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<title type="text">Terence Eden’s Blog</title>
<subtitle type="text">Regular nonsense about tech and its effects 🙃</subtitle>
<updated>2026-09-08T09:42:04Z</updated>
<rights>© Terence Eden. 🄯 CC BY. See https://shkspr.mobi/blog/copyright-and-copyleft/</rights>
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<title type="html"><![CDATA[ActivityPub - Is it worth defending against replay attacks and message/signature time skew?]]></title>
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<id>https://shkspr.mobi/blog/?p=74622</id>
<updated>2026-09-08T09:42:04Z</updated>
<published>2026-09-08T11:34:51Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot"/>
<category scheme="https://shkspr.mobi/blog" term="ActivityPub"/>
<category scheme="https://shkspr.mobi/blog" term="http"/>
<category scheme="https://shkspr.mobi/blog" term="security"/>
<summary type="html"><![CDATA[Here's a problem that I've found with ActivityBot - my little ActivityPub server. Sometimes it receives messages which were originally sent months ago. Why does that happen and is it risky to accept and process them? My tl;dr is that it probably isn't worth worrying about. But I'd love someone to tell me why I'm wrong. Here's my thinking: Table of ContentsCausesIs that a problem?What are we…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/"><![CDATA[<p>Here's a problem that I've found with <a href="https://gitlab.com/edent/activity-bot/">ActivityBot</a> - my little ActivityPub server. Sometimes it receives messages which were originally sent <em>months</em> ago. Why does that happen and is it risky to accept and process them?</p>
<p>My tl;dr is that it <em>probably</em> isn't worth worrying about. But I'd love someone to tell me why I'm wrong.</p>
<p>Here's my thinking:</p>
<p></p><nav role="doc-toc"><menu><li><h2 id="table-of-contents"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#table-of-contents">Table of Contents</a></h2><menu><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes">Causes</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem">Is that a problem?</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against">What are we trying to protect against?</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together">Putting it all together</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it">No! You're wrong and I can prove it!</a></li></menu></li></menu></nav><p></p>
<h2 id="causes"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes">Causes</a></h2>
<p>All ActivityPub messages should have a "published" timestamp in their body. Some will have an "updated" timestamp. That tells you, unsurprisingly, when the message is alleged to have been originally published or updated. That time might be very different to the time you receive the message.</p>
<p>There are, I think, three different reasons why a server might receive a message which has an out-of-date timestamp.</p>
<p>The first is that sometimes servers are just slow. Processing thousands of messages at the same time means that some of those messages take a while to send. <a href="https://shkspr.mobi/blog/2023/09/how-far-did-my-post-go-on-the-fediverse/">ActivityPub is one big chain-mail</a> so it can take several minutes for a message to be sent to all your followers.</p>
<p>Similarly, your server might be slow. If it doesn't acknowledge receipt of a message, the original server will try sending it again. Sometimes that can take a while.</p>
<p>Finally, some servers take a relaxed view of standards. They send an update to an old message but keep the original publication date. Ideally, they'd use an "updated" timestamp but quite often they don't.</p>
<p>For the purposes of checking the legitimacy of the message, <strong>you do not need to check when a message says it was published or updated</strong>. You might want to check it isn't an <em>obviously</em> bogus date like far in the future or impossibly far in the past - but that's up to you.</p>
<p>It is normal that your server receives messages which appear to have been published at a totally different time from now.</p>
<h2 id="is-that-a-problem"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem">Is that a problem?</a></h2>
<p><em>Probably</em> not.</p>
<p>As described above, there are various reasons why a message may be delayed in transit - or may appear to come from the distant past.</p>
<p>What we <em>can</em> check is when the message was cryptographically signed by the sending server. This is independent of its published or updated timestamp.</p>
<p>HTTP requests to your server will have a <code>date</code> header which looks like <code>Tue, 01 Sep 2026 15:54:21 GMT</code> - this is in the slightly peculiar and Anglocentric <a href="https://www.rfc-editor.org/info/rfc5322/#section-3.3">RFC 5322 format</a>.</p>
<p>New style RFC 9421 headers will also have a <code>signature-input</code> header which will contain something like <code>created=1788278061</code>. That uses the slightly obscure <a href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16">UNIX / POSIX time</a> which counts seconds since the "Epoch" of 1st January 1970.</p>
<p>If you <a href="https://www.epochconverter.com/">convert the UNIX time</a> to something more modern, you should get an <em>identical</em> value to the <code>date</code> header.</p>
<p>But that isn't always the case. For example, <a href="https://www.rfc-editor.org/rfc/rfc9421.html#:~:text=Tue%2C%2020%20Apr%202021%2002%3A07%3A55%20GMT,-Content%2DType">the RFC 9421 standard gives this example</a>:</p>
<pre><code class="language-_">Date: Tue, 20 Apr 2021 02:07:55 GMT
"@signature-params": ("@method" "@authority" "@path" \
"content-digest" "content-length" "content-type")\
;created=1618884473;keyid="test-key-rsa-pss"
</code></pre>
<p>Converting <code>1618884473</code> to normal time gives Tue, 20 Apr 2021 02:07:<strong>53</strong> - a two second difference.</p>
<p>If the <code>date</code> and <code>created</code> values differ significantly - that may indicate that the message is untrustworthy. Or that there was a delay between the signing and the sending.</p>
<p>The spec says:</p>
<blockquote><p>The Date header field value represents the timestamp of the HTTP message. However, the creation time of the signature itself is encoded in the created signature parameter. These two values can be different, depending on how the signature and the HTTP message are created and serialized. Applications processing signatures for valid time windows should use the created signature parameter for such calculations. An application could also put limits on how much skew there is between the Date field and the created signature parameter, in order to limit the application of a generated signature to different HTTP messages.</p>
<p><a href="https://www.rfc-editor.org/rfc/rfc9421.html#section-7.2.4">7.2.4. Choosing Signature Parameters and Derived Components over HTTP Fields</a></p></blockquote>
<p>But, of course, it doesn't tell you how much skew is problematic. It's up to you how much skew you're prepared to accept.</p>
<p>So that's the difference between the sent time and the signed time. The next time to check is your own. As we've discussed, sometimes servers are slow sending things out. Would you accept a request that was signed five minutes ago? Five days ago? Five months ago? What amount of difference is dangerous?</p>
<p>Here's what various services and sages have to say:</p>
<h3 id="mastodon"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#mastodon">Mastodon</a></h3>
<blockquote><p>The request contains a Date header. Compare it with current date and time within a reasonable time window to prevent replay attacks.</p>
<p><a href="https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/">How to make friends and verify requests</a></p></blockquote>
<p>What is "reasonable"? The <a href="https://github.com/mastodon/mastodon/blob/89bc0eb42609463d4b11e1604dacc37332a0f5ab/app/lib/signed_request.rb#L5">source code</a> suggests one hour.</p>
<h3 id="grishka"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#grishka">Grishka</a></h3>
<blockquote><p>Time in the Date header must differ from the recipient server’s clock by no more than 30 seconds</p>
<p><a href="https://grishka.me/blog/activitypub-from-scratch/">A bare-minimum ActivityPub server from scratch</a></p></blockquote>
<h3 id="evan-prodromou"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#evan-prodromou">Evan Prodromou</a></h3>
<blockquote><p><code>static #maxDateDiff = 5 * 60 * 1000 // 5 minutes</code></p>
<p><a href="https://github.com/evanp/activitypub-bot/blob/main/lib%2Fhttpsignatureauthenticator.js#L8">activitypub-bot</a></p></blockquote>
<h3 id="swicg"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#swicg">SWICG</a></h3>
<blockquote><p>The standards don't give a concrete time window to use for this comparison. In practice, an hour plus a few minutes buffer in either direction may be a good value, to account for both clock skew and differences in time zone/daylight savings time configuration across systems.</p>
<p><a href="https://swicg.github.io/activitypub-http-signature/#how-to-verify-a-signature">How To Verify a Signature</a></p></blockquote>
<h3 id="others"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#others">Others</a></h3>
<p>Without naming names, it looks like a bunch of popular servers don't check whether there's a significant difference between the date the request was signed and the date it was received.</p>
<h3 id="summary"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#summary">Summary</a></h3>
<p>Various documents and implementations recommend anything between 30 seconds to "a bit more than 60 minutes". Or they just ignore any date difference.</p>
<p>What's the right answer? What happens if the signed date is significantly different from the current date?</p>
<h2 id="what-are-we-trying-to-protect-against"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against">What are we trying to protect against?</a></h2>
<p>Replay Attacks. Suppose someone is listening to the communications between the sending server and your server. They copy the message that is sent to you. Later they send it again!</p>
<p>At this point, you might be thinking "so what?" and… I'm inclined to agree with you!</p>
<p>What's the worst that could happen if you received the same message multiple times? Two things that I can think of.</p>
<p>Firstly, it might <em>not</em> be the same message. It is possible to send a new message but with old headers. An attacker could make someone post "I hate Taylor Swift" against their will and watch as legions of fans disembowel the victim.</p>
<p>Except, I don't think this is likely. The signature in the header contains a hash of the message being sent. If you are properly validating the signature, a changed message will have a different hash from the one in the original message. You don't need to check timestamps, you just need to check if the hashes match.</p>
<p>Secondly, <a href="https://www.freecodecamp.org/news/idempotence-explained">idempotence</a>. That's a fancy word for "pressing the button multiple times should only result in one action".</p>
<p>What happens if a user appears to send you multiple "like" messages for a single post? You only record one like.</p>
<p>What if they send multiple messages with the same content? Well, each will have a unique ID in the message - so you only post it once.</p>
<p>What if they send multiple <em>anythings</em>? I can't think of any ActivityPub action which would not be idempotent.</p>
<p>About the worst thing I can think of is this:</p>
<ul>
<li>Alice sends a message to you saying "I want to follow Bob".</li>
<li>Mallory intercepts this message.</li>
<li>You record Alice is now following Bob.</li>
<li>Alice sends a message to you saying "I want to <em>unfollow</em> Bob".</li>
<li>You record the severed relationship.</li>
<li>Mallory replays the original follow message.</li>
<li>You record Alice is now following Bob.</li>
</ul>
<p>It's also possible the following could happen:</p>
<ul>
<li>Alice posts a message saying "I love The Beatles".</li>
<li>You record Alice's message and display it on the timeline.</li>
<li>Alice updates her post to say "I love the Rolling Stones".</li>
<li>Mallory intercepts this message.</li>
<li>You record Alice's updated message and display the new version on the timeline.</li>
<li>Alice updates her post yet again to say "I love the Spice Girls".</li>
<li>You record Alice's updated message and display the new version on the timeline.</li>
<li>Mallory replays the original update message.</li>
<li>You now display that Alice loves the Stones rather than Spice Girls.</li>
</ul>
<p>Perhaps the same can happen with like/unlike, block/unblock, boost/unboost.</p>
<p>But none of that is significantly prevented by checking the date.</p>
<p>Ultimately, it is up to your sever to check the unique ID of each message and refuse to action any repeated messages. You may not want to trust the unique ID which is sent with the message. If that's the case, you can calculate your own - perhaps using a hash of the contents, the signature, or some other process which will generate an ID based on the message.</p>
<h2 id="putting-it-all-together"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together">Putting it all together</a></h2>
<p>Here's what you need to do to prevent replay attacks:</p>
<ol>
<li>Independently calculate the hash of the message received.</li>
<li>Validate that your calculated hash matches the hash sent in the message's HTTP headers.
<ul>
<li>If not, this is a potential replay attack and the message must be ignored.</li>
</ul></li>
<li>Verify that the signature received in the message's HTTP headers includes the message hash and is cryptographically valid.
<ul>
<li>If not, the signature is invalid and the message must be ignored.</li>
</ul></li>
<li>Has the received message's unique ID already been processed?
<ul>
<li>If so, refuse to process it again.</li>
</ul></li>
</ol>
<p>I don't see what checking the timestamp of the HTTP signature has to do with anything. Someone who has access to the original messages and their headers could send them milliseconds after the original delivery.</p>
<p>I think it is probably <em>pragmatic</em> to give messages 60ish minutes grace before dropping them. Delays happen, but anything more significant than an hour <em>might</em> indicate a attack. But, equally, might just mean that the Internet is having a slow day.</p>
<p>If you are correctly checking signatures and hashes, I don't think you need to worry about skew between signature date and delivery date.</p>
<h2 id="no-youre-wrong-and-i-can-prove-it"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it">No! You're wrong and I can prove it!</a></h2>
<p>Please tell me where I have erred! Stick a comment in the box or drop me an email. If I've made a massive or subtle mistake, I'd love to know what.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74622&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[The purpose of DNS is to spread scams]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/"/>
<id>https://shkspr.mobi/blog/?p=74588</id>
<updated>2026-09-05T17:12:13Z</updated>
<published>2026-09-06T11:34:20Z</published>
<category scheme="https://shkspr.mobi/blog" term="ICANN"/>
<category scheme="https://shkspr.mobi/blog" term="internet"/>
<category scheme="https://shkspr.mobi/blog" term="scam"/>
<category scheme="https://shkspr.mobi/blog" term="spam"/>
<category scheme="https://shkspr.mobi/blog" term="tld"/>
<category scheme="https://shkspr.mobi/blog" term="web"/>
<summary type="html"><![CDATA[I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people …]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/"><![CDATA[<p>I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak</p>
<p>You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people don't. They hastily visit the site, tap in their credit card details, give it their mother's maiden name, confirm address, upload a nude selfie, and only then realise that they've been had.</p>
<p>The Internet works at pretty close to the speed of light. You can register a .uk domain and a minute later it's accessible from the other side of the planet. Brilliant for users who want to quickly launch a website. Also brilliant for abusers who want to launch a spam campaign.</p>
<p>By the time enough people have reported the scammers' domain as suspicious, it is too late. In the time it takes for a registrar to disable the domain, or for its name to make its way to the <a href="https://safebrowsing.google.com/">Safe Browsing List</a>, a million messages have already been sent and enough people have handed over their details.</p>
<p>We're told that "<a href="https://en.wikipedia.org/wiki/The_purpose_of_a_system_is_what_it_does">the purpose of a system is what it does</a>". At the moment, the Domain Name System's purpose seems to be a vector for criminals to run scams on people at a terrifyingly high rate.</p>
<h2 id="how-big-is-this-problem"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#how-big-is-this-problem">How big is this problem?</a></h2>
<p>BIG!</p>
<p>There's a great blog post by Andrew Campling which reports on this startling claim:</p>
<blockquote><p>The study found that at least 10% of all new gTLD domain names registered during the year had subsequently appeared on security blocklists by the time of analysis. It estimated that, taking account of subsequent blocklisting and associated domains not themselves blocklisted, the share of names registered by malicious actors <strong>may be closer to 20%</strong>.</p>
<p><a href="https://labs.ripe.net/author/andrew_campling/dns-abuse-and-criminal-infrastructure-beyond-definitions-and-blocklists/">DNS Abuse and Criminal Infrastructure: Beyond Definitions and Blocklists</a> (emphasis added)</p></blockquote>
<p>That links to a presentation by Interisle which contains some rather shocking statistics (<a href="https://www.icann.org/en/blogs/details/looking-beyond-the-numbers-understanding-malicious-domain-registration-data-10-08-2026-en">albeit with disputed methodology</a>). It looks at <em>generic</em> Top Level Domains (gTLD) - those are things like .com and .fun rather than country code TLDs (ccTLD) like .uk and .de.</p>
<p>It says 85 million new registrations of gTLDs were made in 2025. Of those 8.5 million were added to blocklists by May 2025. It reckons that a 10% abuse rate is the likely floor for these numbers and it's probably closer to 20%. One in five newly registered domains with a gTLD are scams. That's a bloody crisis.</p>
<p>13 TLDs had more than 50% of their registrations blocklisted.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/gTLDs.webp" alt="Table listing the top 13 generic Top-Level Domains (gTLDs) with the highest percentage of blocklisted, malicious new domains created in 2025. Ranked from highest to lowest blocklist percentage, top entries include .LOCKER (72.9%), .LGBT (72.2%), and .TOWN (70.2%). The table detail includes TLD operators, registration totals, and specific malicious domain metrics." width="1162" height="954" class="aligncenter">
<p>I can understand why .bid and .loan are popular with scammers. But why .mobi?! What did I ever do to you, eh?</p>
<p>Who are the scammers registering these through?</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/registrars.webp" alt="List of registrars. NameCheap, Gname, Dynadot, NameSilo, GoDaddy." width="910" height="390" class="aligncenter">
<p>Ah, our old friends at NameCheap. See <a href="https://shkspr.mobi/blog/2021/05/why-do-scammers-love-namecheap/">Why do scammers love NameCheap?</a></p>
<p>If those five registrars had more effective policies, it might significantly dent the scammers' ability to ply their devious wares. Or they might just move on to other registrars.</p>
<p>As the report points out:</p>
<blockquote><p>suspension rates for blocklisted domains were 7.4% to 16.3%.</p></blockquote>
<p><a href="https://interisle.net/s/FullReport_MaliciousRegistrationsintheDomainNameMarket_2026_rev.pdf">The full report is on the Interisle website</a>.</p>
<h2 id="what-can-be-done"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-can-be-done">What can be done?</a></h2>
<p>I don't know.</p>
<p>In the first instance, it might make sense for registrars to do strong Know Your Customer (KYC) checks on anyone buying a domain. But that stops anyone who wants to anonymously register <code>I-Hate-Nintendo.whatever</code> without risking the wrath of Intellectual Property lawyers.</p>
<p>Also, criminals have access to stolen money and stolen cards. They can convince a hapless mule to register a domain on the criminals' behalf.</p>
<p>Registrars could ask for an escrow payment. Pay €9 for the domain name put €900 in escrow. If your domain appears on a blocklist within the year, you forfeit the money. Criminals with stolen funds are unlikely to care but it would probably put off lots of people from getting a new domain.</p>
<p>There are various banned words and phrases depending on the TLD. For example, <a href="https://shkspr.mobi/blog/2024/07/ss-tld-opening-for-direct-registrations/">South Sudan</a> has a list of political words which they don't want associated with their .ss ccTLD.</p>
<p>But if one gTLD bans a word, a different one might not. A scammer doesn't care if the gTLD is .arse or .elbow - they just want the start of the domain to look legitimate.</p>
<p>Some registrars have strings that they don't allow. In fairness to NameCheap, when I tried to register <code>dwp-payments-gov-uk.pizza</code> it told me that domain was banned. It wouldn't let me get any gTLD with that name.</p>
<p>But all it takes is one registrar to be slightly lax and the scammers get through. Increasing the complexity of the rules is also a hell of a burden on smaller registrars.</p>
<p>Besides, it's pretty easy to get a generic enough looking domain and stick the confusing bit on a subdomain. Here are a clutch mentioned in the report:</p>
<ul>
<li><code>https://gov.uk-dwpaph.bond/uk/</code></li>
<li><code>https://gov.uk-dwpcjh.bond/uk/</code></li>
<li><code>https://gov.uk-dwpclc.bond/uk</code></li>
<li><code>https://gov.uk-dwpclw.bond/uk</code></li>
<li><code>https://gov.uk-dwpclj.bond/uk/</code></li>
</ul>
<p>Perhaps there ought to be a delay before a new domain goes live to allow people to object to it? That would give governments, banks, delivery companies, and a dozen more "important" organisations a right to veto any "dodgy" looking domain.</p>
<p>But suppose someone wants to register <code>gov-uk-stole-my-horse.horse</code> to protest the government's cruel policy of stealing horses - is that a legitimate use of a domain? What if the Darwin Pensioner Divas - a group of elderly singers - want to take payments for their new album of goth/punk covers, can the DPD delivery company veto <code>dpd-payments.music</code>?</p>
<p>Do we want a domain name system where powerful companies control exactly which domains we can register? If I have an idea for a domain on a Friday night do I have to wait until Monday before it can be launched? Are those companies realistically able to parse millions of domains per year and have a low false-positive rate?</p>
<p>All of these things are possible - but all of them come with an impact on legitimate users. To be clear, I don't know what the right answer is.</p>
<h2 id="what-is-icann-doing-about-it"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-is-icann-doing-about-it">What is ICANN doing about it?</a></h2>
<p>Lots! It has been a few years since I've been to an ICANN meeting, but even back then the topic of abuse was high on the agenda. They appear to be looking at ways to coordinate abuse reports between various entities, along with some other policies which should hopefully work.</p>
<p>There are two salient points from <a href="https://hosted-files.sched.co/icann86/b3/TRANSC_I86SQV_Mon08June2026__GNSO-DNS%20Abuse%20Mitigation%20PDP%201%20%281%20of%204%29-en.pdf">one of the discussions held at the recent meeting</a></p>
<blockquote><p>If anybody thinks that in our current age of AI and as we move into different kinds of computing, DNS abuse is going to numerically stay steady and we will have a downward effect on that baseline 2027 number. I'm not sure that that's an accurate assumption. I think it's going to be the other thing, which is […] it's going to be easier to abuse the DNS.</p></blockquote>
<p>And</p>
<blockquote><p>Abusers are going to abuse because it's just too lucrative, because no matter what we do, they will find the way to make profit off of that, and will try to circumvent everything that we do. That is not a reason not to do it, though.</p></blockquote>
<p>Quite!</p>
<p>As I said, I don't know the answer to this. What I do know is, much like <a href="https://shkspr.mobi/blog/2025/08/is-it-possible-to-allow-sideloading-and-keep-users-safe/">Android's app ecosystem being a haven for scammers</a>, DNS is facing a crisis. When trust in a system goes, only chaos follows.</p>
<p>I don't want to live in a world where I have to show my passport and pay thousands of pounds to register a domain which is only available after being vetted by private interests. But I also don't want to live in a world where scammers have effectively no deterrent from abusing millions of people.</p>
<p>The purpose of a system is what it does. I hope DNS's purpose can become less dangerous while still remaining open.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74588&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: The Passing of the Dragon and Other Stories by Ken Liu ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/book-review-the-passing-of-the-dragon-and-other-stories-by-ken-liu/"/>
<id>https://shkspr.mobi/blog/?p=74686</id>
<updated>2026-09-05T09:22:57Z</updated>
<published>2026-09-05T11:34:47Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review"/>
<category scheme="https://shkspr.mobi/blog" term="NetGalley"/>
<category scheme="https://shkspr.mobi/blog" term="Sci Fi"/>
<summary type="html"><![CDATA[This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured. What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/book-review-the-passing-of-the-dragon-and-other-stories-by-ken-liu/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/09/9781035929306.webp" alt="Book cover." width="200" class="alignleft">
<p>This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured.</p>
<p>What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a downtown art gallery, the next in the ice-rings of a far-off planet. The creeping feeling of senescence haunts the reader as they flit from story to story.</p>
<p>Much like his full-length novel <a href="https://shkspr.mobi/blog/2025/09/book-review-all-that-we-see-or-seem-by-ken-liu/">All That We See or Seem</a>, Liu has an incredible knack for tapping in to modern fears and weaving tall tales around them. There's a tenderness in all his character - even when a couple of the stories go nowhere, it is still pleasant to spend time in the worlds he has created.</p>
<p>It is, perhaps, missing a cohesive theme - the dragons come and go throughout the stories. Nevertheless, a compelling work chock full of fantastical ideas.</p>
<p>If you're in the mood for a wide and varied selection of stories, this is well worth picking up.</p>
<p>Many thanks to NetGalley for the review copy. Passing of the Dragon is available to buy now.</p>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[A reasonably practical guide to validating RFC 9421 HTTP Signatures for ActivityPub in PHP]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/"/>
<id>https://shkspr.mobi/blog/?p=74429</id>
<updated>2026-09-04T13:36:29Z</updated>
<published>2026-09-03T11:34:12Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot"/>
<category scheme="https://shkspr.mobi/blog" term="ActivityPub"/>
<category scheme="https://shkspr.mobi/blog" term="mastodon"/>
<category scheme="https://shkspr.mobi/blog" term="php"/>
<category scheme="https://shkspr.mobi/blog" term="webdev"/>
<summary type="html"><![CDATA[If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers. This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild. Shut Up And Show Me The Code! OK, wow, no…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/"><![CDATA[<p>If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers.</p>
<p>This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild.</p>
<h2 id="shut-up-and-show-me-the-code"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#shut-up-and-show-me-the-code">Shut Up And Show Me The Code!</a></h2>
<p>OK, wow, no need to be a dick about it! Here's how I validated a real signature that my server received. This requires PHP 8.4 or newer.</p>
<pre><code class="language-php">$verified = openssl_verify(
data: '"@method": POST
"@target-uri": https://example.viii.fi/inbox
"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
"@signature-params": ("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"',
signature: base64_decode( "sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==" ),
public_key: "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\n3QIDAQAB\n-----END PUBLIC KEY-----\n",
algorithm: "sha256"
);
echo $verified;
</code></pre>
<p>Copy and paste that into PHP and you should see that <code>$verified</code> is true.</p>
<h2 id="now-explain-the-code"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#now-explain-the-code">NOW EXPLAIN THE CODE</a></h2>
<p>Say please.</p>
<h2 id="please"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#please">PLEASE!!!</a></h2>
<p>Along with the message sent to your server, you will have received HTTP headers like this:</p>
<pre><code class="language-_">content-digest: sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
signature: sig1=:sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==:
signature-input: sig1=("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"
</code></pre>
<p>The <code>signature-input</code> tells you how to construct a "Signature Base". You have to build a text string which places the various components in the order specified and separated with a newline:</p>
<pre><code class="language-_">"@method": POST
"@target-uri": https://example.viii.fi/inbox
"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
"@signature-params": ("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"
</code></pre>
<p>Where <code>@method</code> is the HTTP method used to send data to your server (usually <code>GET</code> or <code>POST</code>), and <code>@target-uri</code> is the URl the message was sent to (usually your inbox).</p>
<p>The <code>publicKey</code> is slightly trickier. As you can see, the <code>signature-input</code> ends with <code>keyid="https://mastodon.social/users/Edent#main-key</code></p>
<p>If you make a signed request to that URl, you'll get back an ActivityPub Actor document. It will look something like this:</p>
<pre><code class="language-json">{
"@context": [
"https://www.w3.org/ns/activitystreams",
"https://w3id.org/security/v1",
],
"id": "https://mastodon.social/users/Edent",
"webfinger": "Edent@mastodon.social",
"type": "Person",
"name": "Terence Eden",
"publicKey": {
"id": "https://mastodon.social/users/Edent#main-key",
"owner": "https://mastodon.social/users/Edent",
"publicKeyPem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\n3QIDAQAB\n-----END PUBLIC KEY-----\n"
},
</code></pre>
<p>The <code>publicKeyPem</code> is the string you need. There's no need to convert the <code>\n</code> to literal newlines.</p>
<h2 id="is-that-it"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#is-that-it">Is that it?</a></h2>
<p>Not quite! All we've done so far is verify the headers. It is possible that these are genuine headers but attached to a fraudulent body.</p>
<p>This takes us back to the header <code>"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:</code></p>
<p>That says that the body of the message sent has a Base64 encoded SHA256 hash of <code>tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=</code>.</p>
<p>To calculate your own content digest in PHP:</p>
<pre><code class="language-php">$input = file_get_contents( "php://input" );
$digestCalculated = base64_encode(
hash(
algo: "sha256",
data: $input,
binary: true
)
);
</code></pre>
<p>Does your digest match the one sent along with the headers? If not, something dodgy is going on.</p>
<h2 id="putting-it-all-together"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#putting-it-all-together">Putting it all together</a></h2>
<p>The steps are:</p>
<ol>
<li>Get the headers.</li>
<li>Get the body.</li>
<li>From the headers' <code>content-digest</code> extract the algorithm and hash.</li>
<li>Using the body, calculate your own hash using the algorithm from <code>content-digest</code>.</li>
<li>Does your hash match the sent hash? If not, stop. If so, proceed.</li>
<li>From the headers' <code>signature</code> extract the base64 encoded signature.</li>
<li>From the headers' <code>signature-input</code> extract the signature-input string.</li>
<li>From the signature-input string extract the order of the Signature Base.</li>
<li>Construct the Signature Base.</li>
<li>From the signature-input string extract the keyid.</li>
<li>Get the Public Key from the keyid.</li>
<li>Use <code>openssl_verify()</code> to verify the Signature Base and the base64 decoded signature, against the Public Key using SHA256.</li>
</ol>
<p>Note, <a href="https://docs.joinmastodon.org/spec/security/#http-message-signatures">Mastodon <em>only</em> uses SHA256</a>. I think it should explicitly say which algorithm it is using <a href="https://github.com/mastodon/mastodon/issues/29905#issuecomment-5440336919">and have raised the issue</a>.</p>
<h3 id="in-code-form"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#in-code-form">In Code Form</a></h3>
<p>This is how you do it in PHP. Please read this carefully as there are some hard-coded assumptions.</p>
<pre><code class="language-php"><?php
// Validate the Digest.
// It is the hash of the raw input string, in binary, encoded as base64.
// The format is content-digest => <algorithm>=:<base64 encoded hash>:
$digestString = $headers["content-digest"];
// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.
$digestData = explode( separator: "=", string: $digestString, limit: 2 );
// Hashes are in lowercase, but have a `-` in their name.
// This is not what hash_algos() expects.
$digestAlgorithm = str_replace( search: "-", replace: "", subject: $digestData[0] );
// The hash is surrounded by `:` characters.
$digestHash = str_replace( search: ":", replace: "", subject: $digestData[1] );
// Check if the hash algorithm is one known about to PHP.
// If not, reject and record an error.
if ( !in_array( needle:$digestAlgorithm, haystack: hash_algos() ) ) {
return false;
}
// Manually calculate the digest based on the data sent.
$digestCalculated = base64_encode( hash( algo: $digestAlgorithm, data: $input, binary: true ) );
// Does our calculation match what was sent?
if ( !( $digestCalculated == $digestHash ) ) {
return false;
}
// The signature format is signature => <signature name>=:<base64 encoded hash>:
$signatureString = $headers["signature"];
// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.
$signatureData = explode( separator: "=", string: $signatureString, limit: 2 );
$signatureName = $signatureData[0];
// The signature is surrounded by `:` characters.
$signatureB64 = str_replace( search: ":", replace: "", subject: $signatureData[1] );
// The signature-input format is complicated!
$signatureInputString = $headers["signature-input"];
// Get the parameters. Assume there is only one signature.
$signatureParamsString = explode( separator: "=", string: $signatureInputString, limit: 2 )[1];
// Get the different elements of the signature.
$signatureInputData = explode( separator: ";", string: $signatureInputString );
// Construct the data.
$signatureInput = [];
foreach( $signatureInputData as $signatureInputParts ) {
$partsData = explode( separator: "=", string: $signatureInputParts );
// Strip quotes from keyid and parentheses from sig1.
if ( "keyid" == $partsData[0] ) {
$partsData[1] = str_replace( search: "\"", replace: "", subject: $partsData[1] );
}
if ( $signatureName == $partsData[0] ) {
$partsData[1] = str_replace( search: ["(", ")"], replace: "", subject: $partsData[1] );
}
$signatureInput[ $partsData[0] ] = $partsData[1] ;
}
$signatureStructure = $signatureInput[$signatureName];
$signatureKeyID = $signatureInput["keyid"];
// Remove quotes.
$signatureStructure = str_replace( search: "\"", replace: "", subject: $signatureStructure );
$signatureStructureData = explode( separator: " ", string: $signatureStructure );
// https://www.rfc-editor.org/info/rfc9421/#section-2.5
$signatureBase = "";
foreach ( $signatureStructureData as $signatureStructureParts ) {
if ( "@method" == $signatureStructureParts ) {
// https://www.rfc-editor.org/info/rfc9421/#name-method
$signatureBase .= "\"@method\": " . $_SERVER["REQUEST_METHOD"] . "\n";
}
if ( "@target-uri" == $signatureStructureParts ) {
// https://www.rfc-editor.org/info/rfc9421/#section-2.2.2
// Change the domain name to your own.
$signatureBase .= "\"@target-uri\": https://EXAMPLE.COM" . $_SERVER["REQUEST_URI"] . "\n";
}
if ( "content-digest" == $signatureStructureParts ) {
$signatureBase .= "\"content-digest\": $digestString\n";
}
}
// https://victoronsoftware.com/posts/http-message-signatures/#how-the-signature-is-created
$signatureBase .= "\"@signature-params\": $signatureParamsString";
// Get the signing user's public key.
// This is usually in the form `https://example.com/user/username#main-key`
// This is to differentiate if the user has multiple keys.
// This may need to be a signed request. You will need to write your own getDataFromURl() function to get the sending user's key.
$userData = getDataFromURl( $signatureKeyID );
$publicKey = $userData["publicKey"]["publicKeyPem"];
// Verify the request
$verified = openssl_verify(
data: $signatureBase,
signature: base64_decode( $signatureB64 ),
public_key: $publicKey,
algorithm: $digestAlgorithm
);
// Convert the result to boolean.
if ( $verified === 1 ) {
$verified = true;
} elseif ( $verified === 0 ) {
$verified = false;
} else {
$verified = null;
}
return $verified;
</code></pre>
<h2 id="further-reading"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#further-reading">Further Reading</a></h2>
<ul>
<li><a href="https://www.rfc-editor.org/info/rfc9421/">RFC 9421 HTTP Message Signatures</a></li>
<li><a href="https://victoronsoftware.com/posts/http-message-signatures/">Understanding HTTP message signatures: A developer's guide</a></li>
<li><a href="https://www.otoroshi.io/docs/tutorials/http-message-signatures-rfc9421/">Sign and verify HTTP messages (RFC 9421)</a></li>
<li><a href="https://darutk.medium.com/verification-of-http-message-signatures-501bbdc7dfec">Verification of HTTP Message Signatures</a></li>
<li><a href="https://github.com/macgirvin/HTTP-Message-Signer">HTTP-Message-Signer in PHP</a></li>
</ul>
<h2 id="thanks-to-nlnet"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#thanks-to-nlnet">Thanks to NLnet</a></h2>
<p>This blog post was funded in part by the work I'm doing for my NLnet NGI0 grant. Thanks!</p>
<p><a href="https://nlnet.nl/project/ActivityBot/"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp" alt="NLnet logo." width="900" height="200" class="aligncenter"></a></p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74429&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: ActivityPub by Evan Prodromou ★★★★⯪]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/book-review-activitypub-by-evan-prodromou/"/>
<id>https://shkspr.mobi/blog/?p=74414</id>
<updated>2026-08-31T18:53:48Z</updated>
<published>2026-09-01T11:34:18Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityPub"/>
<category scheme="https://shkspr.mobi/blog" term="Book Review"/>
<summary type="html"><![CDATA[As part of my grant from NLnet to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text. Sometimes you just want one book which collates all the info and…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/book-review-activitypub-by-evan-prodromou/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/activitypub.jpg" alt="Book cover with a parrot on it." width="200" class="alignleft">
<p>As part of <a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/">my grant from NLnet</a> to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text.</p>
<p>Sometimes you just want one book which collates all the info and presents it in a consistent format. This is <em>nearly</em> that book.</p>
<p>Evan Prodromou has the unenviable task of making the whole ecosystem easy to understand. Thankfully he does that well. Things are logically laid out, there are comprehensive descriptions of even the most obscure parts of the spec, and it builds up nicely from the fundamentals. Oh, it's also surprisingly light-hearted.</p>
<blockquote><p>This principle is so important and long-winded that web architects have given it an acronym, HATEOAS. (We often pronounce it “HATE-ee-OH-us,” which sounds like a breakfast cereal nobody wants to eat. This is one reason web architects aren’t allowed to name breakfast cereals.)</p></blockquote>
<p>There's an excellent checklist for all the steps needed when building a minimal ActivityPub server.</p>
<p>As with all O'Reilly books, it is a beautifully typeset ePub. Even better, it was supplied DRM-free through Kobo.</p>
<p>About the only significant thing missing is details of how to verify RFC 9421 HTTP Signatures. That's understandable as they're pretty new, but a bit annoying as that's what a lot of servers are sending now. Similarly, there's a good write up of how to publish a poll, but not much about voting or publishing the results.</p>
<p>The "Far Horizons" chapter is particularly exciting - giving a speculative overview of what AP <em>could</em> be used for. I, for one, am particularly looking forward to putting my Internet Connected Fridge on social media 😆</p>
<p>Ultimately ActivityPub is a living and evolving set of standards. No book can possibly keep up with all the changes happening to it - but Evan does a brilliant job of bringing together all the moving parts and creating a coherent picture of the standard.</p>
<p>Highly recommended if you're interested in understanding the fundamentals of the Fediverse!</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74414&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Review: Ruined Theatre's A Midsummer Night's Dream ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/"/>
<id>https://shkspr.mobi/blog/?p=74461</id>
<updated>2026-08-31T09:51:55Z</updated>
<published>2026-08-31T11:34:08Z</published>
<category scheme="https://shkspr.mobi/blog" term="shakespeare"/>
<category scheme="https://shkspr.mobi/blog" term="Theatre Review"/>
<summary type="html"><![CDATA[The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us? Ruined Theatre brings a brilliant cast of seasoned West End performers to strut…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/"><![CDATA[<p>The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us?</p>
<p>Ruined Theatre brings a brilliant cast of seasoned West End performers to strut their hour among the ruins of Abbey Wood. Hey, gentrification has its benefits, OK?</p>
<p><a href="https://www.instagram.com/ruined_theatre/"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/msnd.webp" alt="Poster for the show, an explosion of colour." width="1024" height="527" class="aligncenter"></a></p>
<p>I don't know how many times I've seen "Dream", but I know I've never seen it performed in an actual wood during summer. Booking the tickets a few weeks ago during England's heatwave, it sounded perfect. A warm, dusky evening, accompanied by færies and asses. The British weather, of course, had other ideas.</p>
<h2 id="the-show-must-go-on"><a href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#the-show-must-go-on">The Show <em>Must</em> Go On</a></h2>
<p>The storm clouds were, as the bard wrote, heavy, black and, pendulous. Outside it may be raining, their makeup may be flaking, but everyone knows that Shakespeare is best played when defying the elements, right?</p>
<p>Even in the rain, it was great! Theseus and Hippolyta as selfie-obsessed poseurs made for a delightful start. Recasting Athens as Lesnes was a great touch. And then we were led through the woods. Rather than traipse us from scene to scene, we settled in to a clearing - bringing our own camping chairs with us - and watched the magic unfold.</p>
<p>Half the fun is in watching children and teenagers giggling at Hermia's rage and Bottom's overconfident bombast. But you can't go wrong with actors studiously ignoring the downpour and professing their (misplaced) love for each other. Honestly, who'd lie down in the mud just to make us chuckle? How many laughs can you ring out of a man with an ass's head? Lord, what fools these mortals be!</p>
<p>It is a fairly straightforward production. Aside from modern dress there wasn't much updating of the text other than trimming it down. The smoke machine might have been an eerie touch on a still summer's night, billowing around us, instead the wind took it before it had a chance to settle. The incidental music worked well - especially the intertextuality of Pyramus & Thisbe playing to the Romeo+Juliet soundtrack - but the speakers were over-driven and distorted. A small crimp on an otherwise fine production.</p>
<h2 id="reflections-in-a-dappled-pond"><a href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#reflections-in-a-dappled-pond">Reflections in a dappled pond</a></h2>
<p>I'm fairly sure I once played Demetrius in a youth production. Or possibly Lysander. I know I got to kiss Helena. Or possibly Hermia. The mind plays funny tricks as you age. Some of the more dreary prose becomes light and airy. The laughs which felt forced come more easily. The gender politics a little more nuanced.</p>
<p>You can never go back, of course. But you will always remember your first stage kiss with Hermia (or possibly Helena) with great affection. Seeing Shakespeare again and again and again in a hundred different variations just helps you realise what a master storyteller he was.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74461&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[ActivityBot is the recipient of an NLnet grant!]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/"/>
<id>https://shkspr.mobi/blog/?p=74406</id>
<updated>2026-08-30T10:32:47Z</updated>
<published>2026-08-30T11:34:55Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot"/>
<category scheme="https://shkspr.mobi/blog" term="ActivityPub"/>
<category scheme="https://shkspr.mobi/blog" term="fediverse"/>
<category scheme="https://shkspr.mobi/blog" term="NLnet"/>
<summary type="html"><![CDATA[Back in February, I applied for NLnet's Next Generation Zero grant. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it: Reclaim the public nature of the internet Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up. I run ActivityBot - it is a single-file ActivityPub server suitable for…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/"><![CDATA[<p>Back in February, I applied for <a href="https://nlnet.nl/NGI0/">NLnet's Next Generation Zero grant</a>. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it:</p>
<blockquote><p>Reclaim the public nature of the internet</p>
<p>Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up.</p></blockquote>
<p>I run <a href="https://gitlab.com/edent/activity-bot">ActivityBot</a> - it is a single-file ActivityPub server suitable for launching automated accounts and designed as a learning tool for those who want to understand how the protocol works. Several people have told me how useful it is, but I haven't had the time to make it better. So I decided to stick in a last-minute application to the fund.</p>
<p>I really didn't know how much to apply for - or even if my project would be suitable for funding - so I cheekily asked for €10,000. After a few months of back-and-forth, I'm delighted to announce that I was successful!</p>
<p>In the spirit of openness, this blog post details how the NLnet grant process worked for me and what I'll be using the money for.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp" alt="NLnet logo." width="900" height="200" class="aligncenter">
<h2 id="the-process"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#the-process">The Process</a></h2>
<p>The application was delightfully simple. Here's what it asked for, along with my answers. If you apply, please don't copy these verbatim; use your own words.</p>
<blockquote>
<ul>
<li>Abstract : A single file server for ActivityPub. Designed for write-only bots. Allows any project to quickly and easily start publishing automated content to the Fediverse. Uses PHP, no other dependencies.
</li><li>Experience : I am the sole developer of Single File ActivityPub - https://gitlab.com/edent/activitypub-single-php-file<br>I was formerly the UK Government's representative to the W3C and have contributed to various ActivityPub projects and specifications.
</li><li>Amount : € 10000
</li><li>Use : The fund will be used for development, testing, promotional activity (including conference travel).<br>I anticipate this will fund 6 months of development. I have funded all previous development.<br>
</li><li>Comparison : Most ActivityPub services are complex. They implement a full specification and are designed for multi-user environments. Other projects allow reading and writing. ActivityBot is deliberately designed to be as simple as possible. A single file to upload, one user, publish only.<br>This will enable more projects to be able to instantly start publishing with low development cost and close to zero hosting cost.
</li><li>Challenges : Formal spec verification and a security audit will be the main technical challenges. The ActivityBot software has been running well for over a year. The funding will allow for better compatibility and security.
</li><li>Ecosystem : The project has mostly targeted individuals who want to run small bots. After further development, the project will engage with IoT providers, smaller publishers, open source projects who wish to publish updates, and other relevant parties.
</li></ul>
</blockquote>
<p>I was told there was intense competition. After a couple of months, I received word that I'd made it to the 2nd round.</p>
<p>What then followed was a <em>very</em> polite interrogation about my ideas, how I would develop the project, what I would use the money for, and what my AI usage policy was. They also wanted a breakdown of the main tasks - with the understanding that this would be a provisional document subject to change.</p>
<p>I was on <a href="https://shkspr.mobi/blog/2026/07/another-ridiculous-interrail-holiday-6379km-and-13-countries-over-7-weeks/">a train through Europe</a> when I wrote this. I don't claim it to be a brilliant document - but it got the job done!</p>
<blockquote><p>1. User Research
</p><p>Recruit 2 - 5 potential users. Offer an incentive (approx £20ea) to participate in a user research session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.
</p><p>Total effort 3 - 4 weeks.
</p><p>2. Standards Research
</p><p>Participate in ActivityPub user communities and standardisation groups. Attend virtual conferences (or any local to the UK). Approx 1 day per week for 6 months.
</p><p>3. Test Driven Development
</p><p>Create modern test harness, write test suite, iterate design based on tests. Anticipated effort 2 days per week for approx 3 months.
</p><p>4. Security Testing
</p><p>Work with the community and security professionals to test the resultant code. This will use human testers and normal fuzzers - this will not use AI tools. Anticipated effort 2 days per week for approx 2 months.
</p><p>5. User Acceptance Testing
</p><p>Recruit 2 - 5 potential users (ideally different to the research participants). Offer an incentive (approx £20ea) to participate in a user acceptance session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.
</p><p>Total effort 3 - 4 weeks.
</p><p>6. Updates Based on Research, Testing, and Security
</p><p>While it would be lovely to anticipate getting everything right first time, the reality is that changes will need to be made based on the findings of the above. This will take up the remainder of the allocated time.</p></blockquote>
<p>Again, there was a little more back and forth. But a few weeks later I was informed that I was at the final stage, pending review. And, a few weeks after that, I was told my project had been given the green light.</p>
<p>I was invited to a group call where the very friendly team discussed the practicalities of the grant, what it could and couldn't fund. I also met a bunch of other people who'd also won.</p>
<p>The final stage was writing a proper Memorandum of Understanding. With the help of one of the team (thanks Victoria!) I was able to turn my scrappy plan into something a bit more formal. The project tool NLnet uses made it easy to build up a plan and put € amounts by each task.</p>
<p>The idea is that I will invoice against the grant whenever I have completed a task or sub-task. Obviously I don't want to leave invoicing until the end of the project, but I also need to be mindful of the foreign exchange fees charged by my bank for receiving Euro payments.</p>
<h2 id="final-project-plan"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-project-plan">Final Project Plan</a></h2>
<p>This is the plan I submitted. It represents what I hope to accomplish and how I'll draw down on the grant. I suspect this will change as the months go on.</p>
<hr>
<p>ActivityBot is an Open Source project which aims to develop, maintain, and improve a minimum viable ActivityPub server in a single PHP file.</p>
<p>The project is run by Terence Eden (trading as @edent); a developer residing in England.</p>
<p>This project is expected to run for approximately 6 months. All of the deliverables will be openly licenced using either an OSI approved software licence or a Creative Commons licence.</p>
<p>The high-level aims of the project are for ActivityBot to be:</p>
<ol>
<li><p>A fully compliant ActivityPub server, running in a single PHP file.</p></li>
<li><p>A teaching tool to help developers understand the practical aspects of creating an ActivityPub server.</p></li>
<li><p>A practical method of publishing automated messages to the Fediverse.</p></li>
<li><p>A promotional tool to show how simple and easy ActivityPub development can be.</p></li>
<li><p>A secure and usable tool written in modern PHP.</p></li>
<li><p>Written by humans, with no AI/LLM generated code.</p></li>
</ol>
<p>In light of NLnet's non-profit status, costs assume a discounted rate of €330 per day (£280). Incidentals such as hardware, software, travel, or sundries will be charged at cost with receipts provided.</p>
<h2 id="prepare-for-initial-release"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#prepare-for-initial-release">Prepare for initial release</a></h2>
<p>Ensure that the project is in a suitable state for initial release and future development.</p>
<p>Deliverable: Updates published to GitLab.</p>
<ul>
<li><p>€495 Prepare initial release. Clarify licencing, solicit community engagement, include example usage.</p></li>
<li><p>€495 Standards Research. Collation of standards websites. Ensure code comments refer to specific standards. Publish blog post(s) about findings for others to reference.</p></li>
</ul>
<h2 id="user-research"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-research">User Research</a></h2>
<p>Recruit up to 10 participants for a user-research study. Participants should represent the diversity of the Fediverse.</p>
<p>Investigate what participants want from a tool like ActivityPub. The project plan may be adapted following the results of this study.</p>
<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on the results will be pushed to GitLab.</p>
<ul>
<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>
<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>
</ul>
<h2 id="test-driven-development"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#test-driven-development">Test Driven Development</a></h2>
<p>Create a modern test harness, write test suite, iterate design based on tests.</p>
<p>Deliverable: Tests published to GitLab. Blog posts published about the process and results.</p>
<ul>
<li><p>€330 Set up test suite</p></li>
<li><p>€330 Write tests</p></li>
<li><p>€330 Fixes based on test results</p></li>
</ul>
<h2 id="security-testing"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#security-testing">Security Testing</a></h2>
<p>Working with NLnet's security offering, ensure that the project meets modern security requirements.</p>
<ul>
<li>€720 Work with security team to assess security risks and possible mitigations. Fixes based on security team feedback</li>
</ul>
<p>Deliverable: Updates published to GitLab. Blogs published about the process and results.</p>
<h2 id="user-acceptance-testing"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-acceptance-testing">User Acceptance Testing</a></h2>
<p>Recruit up to 10 participants for a user-acceptance study. Participants should represent the diversity of the Fediverse.</p>
<p>Investigate whether participants are able to use ActivityBot. See which aspects need improvement. The project plan may be adapted following the results of this study.</p>
<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on feedback will be published to GitLab.</p>
<ul>
<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>
<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>
</ul>
<h2 id="conferences-and-standards-work"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#conferences-and-standards-work">Conferences and Standards Work</a></h2>
<p>Open Source participation often depends on attending conferences, either in person or virtually. Getting involved in the standardisation process ensures that future versions of ActivityPub and associated standards will be suitable for the community.</p>
<p>Deliverables: Presentations material (slideware), speaking at conferences (may be published as video), conference outputs. Where possible, these will be available under a suitable Creative Commons licence.</p>
<ul>
<li><p>€700 Travel and accommodation to one EU conference</p></li>
<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>
<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>
</ul>
<h2 id="final-release"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-release">Final release</a></h2>
<p>Creating a final release for this phase of the ActivityBot project. This will involve incorporating all feedback received so far, improving documentation, and publishing code.</p>
<p>Deliverable: Updates published to GitLab. Blog post written. Release announcements.</p>
<ul>
<li><p>€330 Phase 1: Process and implement feedback from users</p></li>
<li><p>€330 Phase 2: Bug fixes</p></li>
<li><p>€330 Phase 3: Features</p></li>
<li><p>€330 Phase 4: Bug fixes</p></li>
<li><p>€330 Phase 5: Features</p></li>
<li><p>€330 Phase 6: Remedial work</p></li>
<li><p>€330 Process and implement feedback from accessibility scan</p></li>
<li><p>€330 Final release</p></li>
</ul>
<h2 id="next-steps"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#next-steps">Next Steps</a></h2>
<p>I've already begun work on updating the code. If you'd like to get involved, or have suggestions or bug reports - please <a href="https://gitlab.com/edent/activity-bot">take a look at ActivityBot on GitLab</a>.</p>
<p>I'll be putting out a call for user-research participants once I've had a chance to catch my breath 😆</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74406&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[A simple "copy this code" button in JavaScript]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/"/>
<id>https://shkspr.mobi/blog/?p=69787</id>
<updated>2026-08-30T18:29:45Z</updated>
<published>2026-08-29T11:34:49Z</published>
<category scheme="https://shkspr.mobi/blog" term="HowTo"/>
<category scheme="https://shkspr.mobi/blog" term="HTML"/>
<category scheme="https://shkspr.mobi/blog" term="javascript"/>
<summary type="html"><![CDATA[Next to all the code samples on this blog is a little "copy" button. That makes it easier to grab any of the code I've shared. The HTML and JS is delightfully simple: <button onclick="navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );" title="Copy code" >⧉</button> The navigator.clipboard.writeText needs a user interaction to w…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/"><![CDATA[<p>Next to all the code samples on this blog is a little "copy" button. That makes it easier to grab any of the code I've shared.</p>
<p>The HTML and JS is delightfully simple:</p>
<pre><code class="language-html"><button
onclick="navigator.clipboard.writeText(
this.parentNode.getElementsByTagName('code')[0].textContent
);"
title="Copy code"
>⧉</button>
</code></pre>
<p>The <code>navigator.clipboard.writeText</code> needs a user interaction to work - so it is tied to a click on the button.</p>
<p>It takes some plaintext content. But how to get that content? My code samples look like this:</p>
<pre><code class="language-html"><pre itemscope itemtype=https://schema.org/SoftwareSourceCode translate=no>
<button onclick="navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );">⧉</button>
<span>
<img alt height=32 src=html.svg width=32>
<span itemprop=programmingLanguage> HTML</span>
</span>
<code itemprop=text>[…]</code>
</pre>
</code></pre>
<p>There are various ways I could get that <code><code></code> element:</p>
<ul>
<li>Give it a unique ID (but that might clutter the code, or conflict with something else).</li>
<li>Use <code>this.nextSibling.nextSibling</code> (but that might not work if the layout changes).</li>
<li>Use <code>this.lastChild.textContent</code> (but, again, depends on the layout staying the same).</li>
<li>Select based on <code>itemprop</code> (could make the code a bit longer).</li>
<li>Complex filtering on a NodeList (urgh).</li>
</ul>
<p>None of those are particularly bad <i lang="la">per se</i>, so I've chosen the method which makes most sense to me.</p>
<p>You can read more about my <a href="https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/">Classless Design</a>, and how I use <a href="https://shkspr.mobi/blog/2024/08/what-programming-language-is-in-this-code-block/">metadata to identify programming languages</a>, including whether <a href="https://shkspr.mobi/blog/2026/01/should-htmls-blocks-be-translated/">HTML's code blocks be translated</a>.</p>
<p>To let people know that it has worked, I've added a little <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/popover">popover</a>.</p>
<p>Every piece of code has it's own <code>dialog</code> element with a unique id:</p>
<pre><code class="language-html"><dialog
id=pop
popover=hint>Copied JS to 📋</dialog>
</code></pre>
<p>No JavaScript is required to show the popover when the copy button is pressed:</p>
<pre><code class="language-html"><button popovertarget=pop popovertargetaction=show>
</code></pre>
<p>Closing the the popover hint doesn't require JS; clicking outside it will dismiss it. But a little scrap of JS on the button's <code>onclick</code> will make it disappear after a few seconds:</p>
<pre><code class="language-js">setTimeout(
function() {
document.getElementById("pop").hidePopover();
},
3000);
</code></pre>
<p>The browser's default is to place it in the middle of the screen.</p>
<p>Positioning the popup so it is in proximity to the button also requires CSS - no JS.</p>
<pre><code class="language-css">dialog[popover] {
inset: unset;
position: absolute;
position-area: top;
padding: .5em;
}
</code></pre>
<p>OK, that started out simple but got a bit more complex. Sorry!</p>
<p><ins datetime="2026-08-30T18:28:40+00:00">Update!</ins> It turns out there are some accessibility issues with this approach. See <a href="https://codepen.io/editor/ccwilcox/pen/01a04d8d-3691-7003-b8f6-df7439ecbd0a">these updates by Curtis Wilcox</a>.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=69787&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<link rel="replies" type="application/atom+xml" href="https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/feed/atom/" thr:count="2"/>
<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA["iT woRKs BeTter in THe aPp!!"]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/"/>
<id>https://shkspr.mobi/blog/?p=73004</id>
<updated>2026-08-25T07:14:14Z</updated>
<published>2026-08-28T11:34:46Z</published>
<category scheme="https://shkspr.mobi/blog" term="android"/>
<category scheme="https://shkspr.mobi/blog" term="Apps"/>
<category scheme="https://shkspr.mobi/blog" term="google"/>
<category scheme="https://shkspr.mobi/blog" term="rant"/>
<summary type="html"><![CDATA[The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation. I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/"><![CDATA[<p>The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation.</p>
<p>I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar app. Is it possible to click on a calendar link and add it to my phone?</p>
<p>No.</p>
<p>Here's what <a href="https://support.google.com/calendar/answer/37100">Google has to say about the matter</a>:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/Google-Calendar-Help.webp" alt="To subscribe to a new calendar, you must use a computer web browser. You can't subscribe to a calendar in the Google Calendar app for Android, iPhone, or iPad." width="920" height="760" class="alignnone size-full wp-image-73005">
<p>Really?!? I mean, fucking <em>really</em>????</p>
<p>This isn't the most complex software engineering task known to humanity. Add a + button. Pop open a text entry field. Validate. Save. Done. I'm sure even the shitty Gemini model can vibe code that in a couple of months, right?</p>
<p>Anyway, I opened calendar.google.com on my phone (using desktop mode), added the calendar, and it magically appeared in the app.</p>
<p>This is just pathetic.</p>
<p>In fairness, this isn't only a Google problem. Many companies want a permanent presence on your homescreen and think you're too thick to use your browser's bookmarks feature. Maybe they're right. Maybe an app <em>is</em> the only way to increase the engagement KPI sufficiently so Quinn in the leadership squad can hit their OKRs and get a bonus.</p>
<p>So they build an app. Or, rather, they half-arse it. I've lost count of the number of times I've been told "it's easier if you use our app" only to be unceremoniously punted back to the web when I try to do anything outside of the app's narrow strictures.</p>
<p>I was there in the early days of phone apps. I built stuff for Symbian, BlackBerry, even the bloody Palm Pilot! The central problem with apps has always been that they are hard to update. Every new bit of functionality - or even a new page - needs to be tested on a thousand devices. Once done, it takes an age to distribute to users. The only way to solve that is to have the app dynamically pull in new functionality from a remote resource.</p>
<p>At which point, you've reinvented the Web browser!</p>
<p>Sure, there are some things you can <em>only</em> do with an app (<a href="https://developer.chrome.com/blog/serial-over-bluetooth/">although browsers are catching up</a>), and having an icon on the homescreen is useful (which is <a href="https://favicon.io/tutorials/favicon-sizes/">easy for sites to add</a>), as is offline functionality (which, again, <a href="https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers">is possible on the web</a>).</p>
<p>Oh.</p>
<p>If you want an app, fine. Do it. Just finish the job please!</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73004&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
<link rel="replies" type="text/html" href="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/#comments" thr:count="10"/>
<link rel="replies" type="application/atom+xml" href="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/feed/atom/" thr:count="10"/>
<thr:total>10</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: The Infinite Sadness of Small Appliances by Glenn Dixon ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/"/>
<id>https://shkspr.mobi/blog/?p=73408</id>
<updated>2026-07-23T22:11:55Z</updated>
<published>2026-08-27T11:34:48Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review"/>
<category scheme="https://shkspr.mobi/blog" term="Sci Fi"/>
<summary type="html"><![CDATA[This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death? It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/Infinite-Sadness-of-Small-Appliances-1-532x815-1.jpg" alt="Book cover." width="200" class="alignleft size-full wp-image-73409">
<p>This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death?</p>
<p>It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a transfem robo-hacker in domestic peril, why clocks are so bossy, and whether art is a cure for grief.</p>
<p>The world-building is a little basic (The Algorithm™ is managing humanity's decline) but the characters are well constructed. A little derivative, it's true. Nevertheless, it is a touching tale, told well, and with a decent pace.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73408&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
<link rel="replies" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/#comments" thr:count="1"/>
<link rel="replies" type="application/atom+xml" href="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/feed/atom/" thr:count="1"/>
<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Gadget Review: Thermal Master P3 Macro Lens ★★★★⯪]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/"/>
<id>https://shkspr.mobi/blog/?p=74230</id>
<updated>2026-08-25T12:37:17Z</updated>
<published>2026-08-26T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="gadget"/>
<category scheme="https://shkspr.mobi/blog" term="infrared"/>
<category scheme="https://shkspr.mobi/blog" term="review"/>
<category scheme="https://shkspr.mobi/blog" term="thermal"/>
<category scheme="https://shkspr.mobi/blog" term="usb-c"/>
<summary type="html"><![CDATA[The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried. Whereas previous cameras are good for bird watching, or wildlife spotting, or finding leaks at home - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics. Yup! See just how hot your CPU is getting…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/"><![CDATA[<p>The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3-thermal-camera-close-up.webp" alt="A small black camera with gold accents. It is held in the fingertips." width="3212" height="2409" class="aligncenter">
<p>Whereas previous cameras are good for <a href="https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/">bird watching</a>, or <a href="https://shkspr.mobi/blog/2026/08/gadget-review-t2-max-plug-in-thermal-camera/">wildlife spotting</a>, or <a href="https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/">finding leaks at home</a> - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics.</p>
<p>Yup! See just how hot your CPU is getting 🥵</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/pi.webp" alt="A thermal image of a raspberry pi. The CPU is in red while the rest of the board is green." width="1344" height="1008" class="aligncenter">
<p>Let's take it for a spin!</p>
<h2 id="unboxing"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#unboxing">Unboxing</a></h2>
<p>As well as the camera (which looks <em>gorgeous</em> with its gold trim) you get a carry-case, USB-C extension cable, and a Lightning converter for older iPhones.</p>
<p>The metal casing of the camera feels delightful and gives it a bit of heft. The focus wheel is reasonably stiff which makes it easier to position just right.</p>
<h2 id="sample-photos"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#sample-photos">Sample Photos</a></h2>
<p>These are the raw images taken directly from the app. I haven't resized or altered them in any way. What you see is what you get. Here's a hot-spot on a circuit board:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/hotspot.webp" alt="A circuit rendered in grey with a bright red line on it." width="1344" height="1008" class="aligncenter">
<p>The natural size of the images is 1344x1008. That's obviously upscaled from the sensor, but there's a surprisingly amount of detail in there.</p>
<p>Here's a small circuit board which has just booted up:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Circuit-long-shot.webp" alt="A small circuit. Two of the chips are noticeably hotter than the rest of the board." width="1344" height="1008" class="aligncenter">
<p>Where the P3 shines is when you twist the manual lens all the way down to macro. You can get about 2cm away from a surface and stay in focus.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Chip-close-up.webp" alt="Close up of a small chip. It is hot, the traces are visible in the background." width="1344" height="1008" class="aligncenter">
<p>Obviously don't get that close to something red hot!</p>
<p>Annoyingly, the images are uncompressed JPEG and weigh in around 6MB each. I've losslessly compressed these to WebP, which is about 10% of the size.</p>
<h3 id="colours"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#colours">Colours</a></h3>
<p>There are a variety of different colour palettes to play with. Some are more useful than others. Here's a mug of hot and delicious matcha rendered in the various colours:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Hot-Tea-Montage.webp" alt="Four photos of a mug. The colours show how hot the tea is." width="2688" height="2016" class="alignleft">
<p>Scrolling through the colours is a little difficult in the app (more on that later) but once you've found one you like, it stays that way for the photography session.</p>
<h3 id="exif"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#exif">EXIF</a></h3>
<p>Geolocation is taken from the phone - there's no GPS chip in the camera. You can refuse location permission to the app and it will work just fine.</p>
<p>That's just about all you get other than the time and the model name of <code>USB_IR_RS300_P2L</code> - the infrared details aren't recorded separately.</p>
<h2 id="video"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#video">Video</a></h2>
<p>The video doesn't upsample the image, it has a resolution of 504x672 playing at 25fps. Audio is recorded from the phone's microphone and is 64kbps mono. A minute of video is around 22MB. I've recompressed this one for the web.</p>
<p></p><div style="width: 620px;" class="wp-video"><video class="wp-video-shortcode" id="video-74230-2" width="620" height="465" preload="metadata" controls="controls"><source type="video/mp4" src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4?_=2"><a href="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4">https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4</a></video></div><p></p>
<h2 id="the-app"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#the-app">The App</a></h2>
<p>It is, sadly, an inevitability that good hardware is always accompanied by a substandard app. The <a href="https://play.google.com/store/apps/details?id=com.thermalmaster.p2telephoto">Thermal Master Android App</a> is the only way to access the camera. It has a relatively easy to use interface with plenty of options.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Camera-interface.webp" alt="Camera interface with janky UI." width="504" class="aligncenter">
<p>As you can see from the word "brightness" the UI is a little janky in places.</p>
<p>There's a decent amount of settings to fiddle with.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/more-settings.webp" alt="Settings screens with various temperature settings." width="504" class="aligncenter">
<p>You can also change which elements get displayed on the final image.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/settings.webp" alt="Settings to control the camera." width="504" class="aligncenter">
<p>Unfortunately, it is also a bit crash-happy. Most times I used it, the app would randomly close. It takes a little while to re-open thanks to a mandatory animation. So it gets a bit annoying. Flicking through some of the options can be slow and tedious. It also doesn't respect the phone's orientation, so images may be 90⁰ off what you expect.</p>
<p>The app updated the firmware on the camera, but didn't say what had changed.</p>
<p>It takes photos and videos, allows you to share them, and has a bunch of options to play with - but it does have a habit of crashing just when you're about to take the perfect shot. There is also zoom available, but it is digital only - so you're just making the pixels bigger rather than getting optically closer to the object you're scanning.</p>
<h2 id="linux-info"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#linux-info">Linux Info</a></h2>
<p>I tried plugging it in to a Linux laptop. It shows up as <code>3474:45a2 Thermal Master Technology Co., Ltd. P3</code> - but that's about it. There's no way I can find to access the thermal images.</p>
<p>To be fair, this is explicitly sold as an Android and iOS device. I'm hopeful someone will be able to reverse engineer it.</p>
<h2 id="cost-and-final-thoughts"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#cost-and-final-thoughts">Cost and Final Thoughts</a></h2>
<p>Thermal cameras are expensive. This will run you about <a href="https://link.amazon/B0aFBVuY9">£280 on Amazon</a> or about <a href="https://thermalmaster.com/en-gb/products/p3-thermal-camera-for-iphone-and-android">£260 direct</a>. Readers of this blog can get 10% off using code <code>THERMALBF10</code></p>
<p>If you run a hackspace, this is a no-brainer. The ability to see hot-spots on your circuits is immediately useful. The detail is impressive, allowing you to see exactly what's causing problems.</p>
<p>If you're a hobbyist, this is definitely in the "ask Santa if you've been good" category. You'll find it handy on any small projects you have, or to diagnose faults with electrical equipment.</p>
<p>For non-macro uses, it's also pretty good. You might be better off with a dedicated device if you want to go <a href="https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/">hunting wildlife</a> or doing <a href="https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/">home surveys</a>.</p>
<p>The only fly in the ointment is the app. While somewhat customisable, it does repeatedly crash and it isn't the easiest to use or set up. I found that pretty frustrating and have fed back the problem to the developers. I appreciate it saving high quality images - but a PNG or lossless WebP would be easier to work with than massive JPGs.</p>
<p>Ultimately, this is an excellent thermal camera. It looks lush, it is customisable, the images are high quality, and the macro-lens is surprisingly useful.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74230&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
<link href="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4" rel="enclosure" length="3235198" type="video/mp4"/>
<link rel="replies" type="text/html" href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#comments" thr:count="0"/>
<link rel="replies" type="application/atom+xml" href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/feed/atom/" thr:count="0"/>
<thr:total>0</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Theatre Review: Cats at Regent's Park Open Air Theatre ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/theatre-review-cats-at-regents-park-open-air-theatre/"/>
<id>https://shkspr.mobi/blog/?p=74380</id>
<updated>2026-09-01T22:02:57Z</updated>
<published>2026-08-25T11:34:22Z</published>
<category scheme="https://shkspr.mobi/blog" term="musical"/>
<category scheme="https://shkspr.mobi/blog" term="Theatre Review"/>
<summary type="html"><![CDATA[Cats is so silly! In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature. Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/theatre-review-cats-at-regents-park-open-air-theatre/"><![CDATA[<p>Cats is so <em>silly!</em></p>
<p>In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature.</p>
<p>Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in service of better understanding the mysteries of our moggies.</p>
<p>Does there need to be so many sequins? So much dry ice? Such a quantity of pyrotechnics?</p>
<p>No, probably not. But it all adds up to a spectacular which will keep you grinning.</p>
<p>The deficiencies in Cats are somewhat inherent. The scrapbook story doesn't make a lick of sense. It is more like a variety show than musical theatre. The lyrics are, at times, utterly asinine. The music soars, until someone starts playing what sounds like a genuine 1980s Casio keyboard - and all you can hear is squelch.</p>
<p>But then Gary Wilmot (!!!) comes on as Gus and all is forgiven on a haze of metatextual glory.</p>
<p>The choreography and dancing are exemplary. The singing occasionally gets muddled but is mostly delightful. The stage is perfect - the wind blowing through the trees and the moon gently rising only helps to accentuate the atmosphere.</p>
<p>The pre-show is good. As well as a variety of food stalls, patrons are encouraged to bring their own food and drink for a picnic. There are plenty of tables and a couple of selfie points.</p>
<p>The programme isn’t horrendous at £6 but still feels like it contains more advertising than content. The queues for the loos were outrageously long and the stalls weren't particularly clean.</p>
<p>There's nothing to do post-show except trudge back through the park. The selfie point is still illuminated if you want to queue for that. Even the t-shirt sales stopped after the interval.</p>
<p>I first saw Cats in the West End some time in the 1980s as a child and loved it. Afterwards my parents asked if I wanted to see a ballet or an opera next. "Eurgh! No! <em>Boring!</em>" I said. They politely informed me that I'd just seen both in one show and my juvenile mind was blown.</p>
<p>A few decades later I saw Cats on Broadway - shortly before it closed, I think. The C90 cassette they used to play the music was warbling like a demented bird and the sets looked equally tired. Despite the half empty auditorium, the cast attacked the songs with vigour. I still loved it.</p>
<p>And, today, I still had goosebumps. Maybe it was the unseasonable chill in the air, maybe it was the moonlight, or maybe it was the magic of Cats!</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Why do audience members choose specific shows at the Edinburgh Fringe?]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/"/>
<id>https://shkspr.mobi/blog/?p=74330</id>
<updated>2026-09-01T22:05:06Z</updated>
<published>2026-08-24T11:34:45Z</published>
<category scheme="https://shkspr.mobi/blog" term="data"/>
<category scheme="https://shkspr.mobi/blog" term="EdFringe"/>
<summary type="html"><![CDATA[On our recent trip to the Edinburgh Fringe, I was bemused by just how little effort performers put in to finding out why people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with some performers paying tens of thousands of pounds. The way performers recoup the costs of performing is by getting people to pay to see a show. Acts are spending huge amounts…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/"><![CDATA[<p>On our <a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/">recent trip to the Edinburgh Fringe</a>, I was bemused by just how little effort performers put in to finding out <em>why</em> people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with <a href="https://www.scotsman.com/business/edinburgh-festival-fringe-2025-the-true-cost-of-performing-at-the-worlds-largest-arts-event-laid-bare-5247134">some performers paying tens of thousands of pounds</a>. The way performers recoup the costs of performing is by getting people to pay to see a show.</p>
<p>Acts are spending huge amounts on flyers, posters, and other promotional activities. But is any of it worthwhile?</p>
<p>The performer Danielle Solof has a fascinating blog post "<a href="https://daniellesolof.substack.com/p/my-real-fringe-budgets-line-by-line">My Real Fringe Budgets, Line-by-Line</a>" which details the actual costs of her taking two solo shows to the Fringe. She meticulously details the price of everything from transport and food, to advertising and graphic design. She says:</p>
<blockquote><p>I paid for outdoor ads because absolutely no one in Edinburgh knew who I was. They <em>did</em> help, but you still have to grind to get an audience in.</p></blockquote>
<p>My question to her - and all performers - is how do you know what drives an audience member to see your show?</p>
<p>It can't have escaped your attention that everything we do online is tracked. If you buy so much as a toothpick, the retailer knows which YouTube reviews you watched, which words you searched for, the other products you considered, and the specific adverts you clicked on.</p>
<p>In Edinburgh, no one knows nothing.</p>
<p>At the end of nearly every show the performer begged us to leave a review on the Fringe website and to tell our friends. In absolutely <em>none</em> of the shows did the performer ask why we were there, how we found out about the show, which poster or leaflet attracted us, or whether we followed them on social media.</p>
<p>All that money spent on posters and no one knows if they work. As the old saying goes "<a href="https://quoteinvestigator.com/2022/04/11/advertising/">Half the money I spend on advertising is wasted, and the trouble is I don’t know which half.</a>".</p>
<p>So, in an attempt to bring a <em>little</em> data to proceedings, here are how we chose the 26 shows we saw. I don't claim this is representative of everyone, but I think it might be illustrative. In rough order of importance were:</p>
<h2 id="proximity"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#proximity">Proximity</a></h2>
<p>The EdFringe app has a "nearby now" feature. Click on it and you get a list of shows starting soon which are only staggering distance away.</p>
<p>I cannot stress enough how much of a motivator that was. When you've spent all day traipsing, the last thing you want to do is <em>another</em> 20 minute walk uphill to see a provocative new piece of challenging theatre told through finger puppets.</p>
<p>About 20% of the shows we saw were via that feature.</p>
<p>Roughly another 40% were because the show was close to something else we really wanted to see. We knew that we wanted to see show X, so we looked for shows which weren't too far away from that venue. Yes, Edinburgh is a compact city with decent public transport, but it is much easier to walk round the corner or stay to have a drink in the venue's bar.</p>
<p>You can <em>really</em> want to see a show, but if it is a 20 minute walk between venues and it starts 15 minutes after your last show ends, you'll skip it. I'd say that location was the key driver in most of our choices.</p>
<p>I guess my top tip to any performer would be to be as near as physically possible to a bigger act!</p>
<h2 id="friends"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#friends">Friends</a></h2>
<p>A quarter of the shows we went to were because either a friend-of-a-friend was performing, or a friend booked tickets and asked if we wanted to tag along.</p>
<p>You are morally obliged to go to your friends' shows. Similarly, if a mate says "Oh, my friend has a show on this year", you have to make the effort to go.</p>
<p>Perhaps it is a bit blasé to say that word-of-mouth works, but it's a cliché becausé it is trué.</p>
<h2 id="flyers-and-leaflets"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#flyers-and-leaflets">Flyers and Leaflets</a></h2>
<p>We collected approximately 5,374 different promotional leaflets during our week there. Most of the time we were handed a leaflet by someone paid to hand out leaflets. They were either wordlessly stuffed into our hands, or delivered with a monotone "wanna see improv comdy?" Bleh.</p>
<p>A few actually spoke to us about the show when we asked questions, which was a deciding factor in seeing a couple of performances.</p>
<p>The best flyerers were, undoubtedly, the performers themselves. Kat Ronson in her <a href="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-kat-ronson-millennial-girl/">Millennial Girl</a> guise drawled at us "You look thin and pretty. You're allowed to come to my show." Instant sale!</p>
<p>Similarly, one rather famous comedian walked up to us and said "You look like theatre people!" and proceeded to pitch their show - which was a delightful encounter and would have sold us a ticket if we weren't leaving that day.</p>
<p>Some flyers had a QR code or URl on them so we could watch a trailer of the show. We didn't watch any of them. Perhaps we should have?</p>
<h2 id="posters"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#posters">Posters</a></h2>
<p>Surprisingly effective at drawing the eye! The ones which were just a photo of the comedian looking a bit "whacky" were dull. The ones of performers in their most seductive poses were a little naff. The ones which were just a close up of someone's face only really work if that person is incredibly famous, otherwise you're just left thinking "who?"</p>
<p>But a few posters made us stop and immediately search for the show. Graphic design is a professional skill and one worth investing in.</p>
<p>Some posters were everywhere. I took an instant (and uncharitable) dislike to one poster featuring a smug-looking twat and I swear he followed me around town. Some posters only appeared near the performance venue.</p>
<p>Incidentally, there were a couple of posters which had clearly just been fed into an AI generator. Lazy and off-putting.</p>
<h2 id="reviews"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#reviews">Reviews</a></h2>
<p>The Fringe doesn't allow weighted star reviews - so you can't immediately see if the consensus is that the show is a hit or a miss. Several of the shows we didn't enjoy got excellent reviews (from morons) and some of the shows we loved were panned (presumably by the same morons).</p>
<p>In truth, I don't think the reviews influenced our decision to see anything.</p>
<h2 id="what-stopped-us-going-to-shows"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#what-stopped-us-going-to-shows">What <em>Stopped</em> Us Going To Shows</a></h2>
<p>For every action there is an equal and opposite reaction. I think it is important for performers to know what stopped someone clicking the "buy" button for their show.</p>
<h3 id="ticket-cost-value-for-money"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#ticket-cost-value-for-money">Ticket Cost / Value For Money</a></h3>
<p>Mondays and Tuesdays saw lots of shows doing a 2-for-1 promotion. I didn't mind spending £30 for two of us to take a risk on something. Come Wednesday, I wasn't prepared to pay £60 for a 45 minute show.</p>
<p>I know "surge pricing" gets a bad rap, but <a href="https://shkspr.mobi/blog/2024/09/why-does-no-one-discuss-negative-dynamic-pricing/">dynamic pricing of underselling shows</a> might help. If you've only sold four seats for today, perhaps drop the price? I don't know if the Fringe software supports that - but it seems obvious to me that having 10 people paying a fiver is better than four people paying a tenner.</p>
<h3 id="crap-signal-long-queues"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#crap-signal-long-queues">Crap Signal / Long Queues</a></h3>
<p>We tried to get in to a circus show. My phone didn't have enough signal for the app to work and the nearest box office had a massive queue. So we bailed.</p>
<p>If the venue had WiFi (not a given, weirdly) it would have gotten them an extra sale. If the ticket staff could take contactless (lots of performers did) we'd have happily paid.</p>
<p>You have to make it easy for people to give you money.</p>
<h3 id="not-enough-time"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#not-enough-time">Not Enough Time</a></h3>
<p>This is completely out of the performers' control. We had 6 days and saw about 4 shows per day. We could have seen more, but we needed to eat, explore, and sleep.</p>
<p>Speaking of which, there were several midnight performances which looked excellent - but I also needed to get up the next day to see more shows. Sleep won!</p>
<h3 id="too-famous"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#too-famous">Too Famous</a></h3>
<p>I'd love to see that guy who's on the telly. But I can watch him on the telly. That show looks like a massive success, so I'm sure it'll tour round London soon.</p>
<h3 id="sell-outs"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#sell-outs">Sell Outs</a></h3>
<p>A few shows sold out before we could get tickets. Good for them! If that was your show, you probably don't need this blog post.</p>
<h2 id="better-art-through-commerce"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#better-art-through-commerce">Better Art Through Commerce</a></h2>
<p>Art should be driven by passion.</p>
<p>But every performer I know listens back to their shows to see what works and what didn't. If a joke falls flat, it's cut. If a riff gets a big laugh, it's incorporated. That's the essence of data driven decision making.</p>
<p>I wish every performer at the Fringe had a sell out audience and were able to recoup their costs. But that is never going to happen unless they spend time understanding what gets bums on seats.</p>
<p>So here are a few scattered thoughts on how they could do that.</p>
<ul>
<li>QR code at the end of the show leading to a survey. Literally ask people "what made you choose this performance?"</li>
<li>In the queue before the show, or as people are taking their seats, hand out a paper questionnaire.</li>
<li>Talk to the audience after the show. See if you can gain any insights about what made them attend.</li>
<li>As people are coming in, have a poster asking people to tick a box based on how they heard about the show.</li>
<li>Give each leaflet a unique code (or a code per person handing them out). Ask people to bring the leaflet with them so you can see which area/person/leaflet was most effective.</li>
<li>Each poster can have a unique QR code on it. Track whether the one by the station led to more ticket sales than the one in the underpass. Did the one in the gents toilets get <em>any</em> scans at all?</li>
</ul>
<p>Of course, all of the above rely on talking to people who made the choice to see you. This is classic <a href="https://en.wikipedia.org/wiki/Survivorship_bias">Survivorship Bias</a>. Sure, it'll help you work out what was <em>successful</em>, but you won't know why people looked at your show and chose something else. That said, it is <em>hard</em>. How do you find people who <i lang="la">ipso facto</i> aren't at your show?</p>
<ul>
<li>That could be as simple as asking people what they dislike about the leaflet when you hand it out.</li>
<li>Each poster or leaflet can have a unique QR code on it. Which ones cause people to scan, but then abandon the idea of buying a ticket?</li>
<li>Speak to people who came to the venue for a show other than yours. They obviously like the location, so non-confrontationally ask them why they didn't pick you?</li>
</ul>
<p>Some of these are easier than others. By themselves, they might give you a slightly misleading view of the data. But surely anything is better than looking at a half empty venue and wondering if those huge advertising costs did any good at all.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Death to px, long live ch!]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/death-to-px-long-live-ch/"/>
<id>https://shkspr.mobi/blog/?p=63847</id>
<updated>2026-08-23T12:45:06Z</updated>
<published>2026-08-23T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="css"/>
<category scheme="https://shkspr.mobi/blog" term="design"/>
<category scheme="https://shkspr.mobi/blog" term="HTML"/>
<summary type="html"><![CDATA[Pixels are a lie. Even if you think you're drawing something with "pixel perfect" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares. In CSS, pixels are a double lie: Note that 1px doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, 1cm in CSS often doesn't correspond to one hundredth of SI…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/death-to-px-long-live-ch/"><![CDATA[<p>Pixels are a lie. Even if you think you're drawing something with "<a href="https://shkspr.mobi/blog/2018/11/the-myth-of-the-pixel-perfect-grid/">pixel perfect</a>" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares.</p>
<p>In CSS, <a href="https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/Values_and_units#lengths">pixels are a double lie</a>:</p>
<blockquote><p>Note that <code>1px</code> doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, <code>1cm</code> in CSS often doesn't correspond to one hundredth of SI meter. On a large TV screen, it typically is longer than that. The lengths are perceptual: <code>16px</code> looks roughly the same on a phone, laptop, or TV screen at typical viewing distance.</p></blockquote>
<p>This blog is primarily text based. I want the <a href="https://journals.uc.edu/index.php/vl/article/view/5765/4629">width of the text to be readable</a> for the average human. So, rather than setting the main width to be a percentage of the screen, I set it based on character width using the <code>ch</code> unit - which <a href="https://meyerweb.com/eric/thoughts/2018/06/28/what-is-the-css-ch-unit/">isn't exactly a character</a> but good enough for my purposes:</p>
<pre><code class="language-css">--width-content: min(75ch, 100%);
main {
max-width: var(--width-content);
}
</code></pre>
<p>When it comes to padding and margins, the same is true. If I want a gap around an element, I want that gap to be in proportion to the text inside it.</p>
<p>For widths, it makes sense to re-use the <code>ch</code> unit. I want the gap to be in proportion to the text.</p>
<p>But for <em>height</em>, perhaps it doesn't make sense to express vertical distance on character width? In which case <a href="https://www.w3.org/Style/Examples/007/units.en.html">the <code>ex</code> unit can be used</a>. It is the size of a typical lower-case letter.</p>
<p>Just like my idea to <a href="https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/">eliminate CSS classes from my HTML</a>, it's possible to go too far with this. I haven't changed <em>every</em> reference from px to ch, I'm just experimenting to see if it works.</p>
<p>There's nothing wrong, immoral, or evil about using px - or any other measure unit. Using ch and ex fit with my particular proclivities.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=63847&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: An Immense World - How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong ★★★☆☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-an-immense-world-how-animal-senses-reveal-the-hidden-realms-around-us-by-ed-yong/"/>
<id>https://shkspr.mobi/blog/?p=72903</id>
<updated>2026-07-29T09:03:25Z</updated>
<published>2026-08-21T11:34:36Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review"/>
<category scheme="https://shkspr.mobi/blog" term="science"/>
<summary type="html"><![CDATA[This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision. This isn't a game of Top Trumps where all the animals are ranked by power.…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-an-immense-world-how-animal-senses-reveal-the-hidden-realms-around-us-by-ed-yong/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/9781473572737-jacket-large.webp" alt="Book cover featuring various animals." width="200" class="alignleft size-full wp-image-72904">
<p>This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision.</p>
<p>This isn't a game of Top Trumps where all the animals are ranked by power. Instead there's a gentle and passionate exploration of what these senses <em>might</em> mean to their owners. It is refreshingly candid about what we don't know, while always trying to convey a sense of wonder about the inherent <a href="https://en.wikipedia.org/wiki/Umwelt"><i lang="de">Umwelt</i></a> experienced by the animal.</p>
<p>But goodness me is it long. It seems that every time the editor told the author to cut out a paragraph, he stuck it in a footnote instead. The text is well referenced, but so are the footnotes, which means occasionally encountering sentences formatted like this:</p>
<blockquote><p>Despite several frustrating false leads, nobody’s ever found them.<sup>fn11,36,37,38,39</sup></p></blockquote>
<p>Speaking of which, the general formatting of the eBook is poor. The CSS contains all sorts of weird stuff which I needed to turn off, and is full of comments which probably should have been stripped before the book was distributed.</p>
<p>Science publishers still haven't grasped that eBooks don't need to relegate glossy images to the back of the book - they can go inline with the text!</p>
<p>This is a funny, heartfelt, and (perhaps overly) thorough book. It will gleefully send you down rabbit holes - even if you're ill-equipped to see in the dark and sense the bugs around you.</p>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Asymmetric Agents]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/asymmetric-agents/"/>
<id>https://shkspr.mobi/blog/?p=73594</id>
<updated>2026-08-20T06:17:00Z</updated>
<published>2026-08-19T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="agentic"/>
<category scheme="https://shkspr.mobi/blog" term="AI"/>
<category scheme="https://shkspr.mobi/blog" term="future"/>
<summary type="html"><![CDATA[One of the promises of the AI-filled future is that we'll all have highly capable autonomous servants "agents" to work for us. Even back in the 1990s, it was a common trope in future-gazing to insist that a person's personal slave agent would negotiate on their behalf. Ask your meek digital pal agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, …]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/asymmetric-agents/"><![CDATA[<p>One of the promises of the AI-filled future is that we'll all have highly capable autonomous <del>servants</del> "agents" to work for us.</p>
<p>Even <a href="https://shkspr.mobi/blog/2026/02/how-close-are-we-to-a-vision-for-2010/">back in the 1990s</a>, it was a common trope in future-gazing to insist that a person's personal <del>slave</del> agent would negotiate on their behalf. Ask your <del>meek digital pal</del> agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, and within your budget. The little <del>butler</del> agent scurries off and, without your intervention, finds the <em>perfect</em> place, negotiates with the restaurant's <del>house boy</del> agent and books you a slap up meal.</p>
<p>Marvellous! You can tell your <del>manservant</del> agent to buy you clothes, reserve a flight, do the grocery shopping, or buy your wife flowers without having to lift a finger.</p>
<p>But, of course, there's a fly in the ointment. Not all <del>valets</del> agents are created equally. You're sending your Raspberry Pi powered <del>peon</del> agent against the full might of Amazon's bazillion datacentres.</p>
<p>Can a low-complexity <del>serf</del> agent be bullied, outwitted, and manipulated by a more capable <del>henchman</del> agent? It seems obvious to me that the answer is yes. Humans have a set of cognitive biases which render us susceptible to advertising tricks. AI may have <a href="https://cacm.acm.org/research/rolling-in-the-deep-of-cognitive-and-ai-biases/"><em>different</em> biases</a> but will still be vulnerable to <a href="https://shkspr.mobi/blog/2017/03/how-to-hypnotise-an-artificial-intelligence/">hypnosis</a> and hacking.</p>
<p>Perhaps having my <del>secretary</del> agent negotiate with your <del>PA</del> agent to find a suitable meeting time for our Q2 KPI Deep Dive doesn't carry this sort of risk. But I'm sure that <del>scumbags</del> advertisers everywhere will be salivating at the thought of waylaying my innocent <del>footman</del> agent on its way to market.</p>
<p>A future where we delegate responsibility to <del>stochastic imbeciles</del> agents is one where we accept that we have no control over their susceptibility to more powerful and malevolent <del>thugs</del> agents.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73594&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[And then the men with guns tell you to do it anyway]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/and-then-the-men-with-guns-tell-you-to-do-it-anyway/"/>
<id>https://shkspr.mobi/blog/?p=74161</id>
<updated>2026-08-17T11:31:25Z</updated>
<published>2026-08-17T11:34:24Z</published>
<category scheme="https://shkspr.mobi/blog" term="politics"/>
<category scheme="https://shkspr.mobi/blog" term="technology"/>
<summary type="html"><![CDATA[In early February 2011 Egypt was in the middle of a political revolution. One morning, everyone's phones suddenly pinged with an alert. The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt. A series of messages arrived all ostensibly from the network provider Vodafone. All pro-regime and all with the…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/and-then-the-men-with-guns-tell-you-to-do-it-anyway/"><![CDATA[<p>In early February 2011 <a href="https://www.aljazeera.com/news/2023/1/25/what-happened-during-egypts-january-25-revolution">Egypt was in the middle of a political revolution</a>. One morning, everyone's phones suddenly pinged with an alert.</p>
<blockquote><p>The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt.</p></blockquote>
<p>A <a href="https://www.flickr.com/photos/59098813@N06/5411904816/in/photostream/">series of messages arrived</a> all ostensibly from the network provider Vodafone. All pro-regime and all with the undercurrent of violence.</p>
<p>Why did Vodafone send these messages? Earlier in the week, <a href="https://www.hrw.org/news/2011/01/28/egypt-nationwide-internet-blackout-endangers-rights">all Internet access was cut off</a> now phones were blasting propaganda to the masses.</p>
<p>After the network went down, Vodafone issued a statement saying:</p>
<blockquote><p>It has been clear to us that there were no legal or practical options open to Vodafone, or any of the mobile operators in Egypt, but to comply with the demands of the authorities.</p></blockquote>
<p>Do you have to follow orders? Do you have to obey the law even when it is unjust? Should multinational corporations instruct local executives to be loyal to their parent company or the rulers of the country they live in?</p>
<p>After the messages came in - including promises that "<a href="https://www.theguardian.com/news/blog/2011/feb/03/egypt-protests-live-updates#block-19">The Armed Forces cares for your safety and well being and will not resort to using force against this great nation</a>" - Vodafone Global, safely ensconced in the UK, put out another statement:</p>
<blockquote><p>Under the emergency powers provisions of the Telecoms Act, the Egyptian authorities can instruct the mobile networks of Mobinil, Etisalat and Vodafone to send messages to the people of Egypt. They have used this since the start of the protests. These messages are not scripted by any of the mobile network operators and we do not have the ability to respond to the authorities on their content.</p>
<p>Vodafone Group has protested to the authorities that the current situation regarding these messages is unacceptable. We have made clear that all messages should be transparent and clearly attributable to the originator.</p>
<p><a href="https://web.archive.org/web/20110307151856/http://www.vodafone.com/content/index/press/press_statements/statement_on_egypt.html">Statements - Vodafone Egypt</a></p></blockquote>
<p>A few years later I was at a networking event chatting to a guy. We'd both previously worked for Vodafone. Me in the UK, he in Egypt. I asked him about the incident - he talked about how they built the SMS infrastructure, what they did to secure it, how they prevented spam, and how one day armed men arrived.</p>
<p>I suspect most of us have seen a movie where some flunky in an office refuses the baddies demands to open the safe, and then gets shot in the head. Perhaps you think that's a noble death? He lived with honour and refused to yield! But, in every movie I've seen, the guy's subordinate opens the safe anyway and gets to live.</p>
<p>But we're technologists, right? We can build fail safes and cryptographic proofs and <a href="https://knowyourmeme.com/memes/i-would-simply">simply build infrastructure that can't be abused</a>.</p>
<p>And then the men with guns come and tell you what to do.</p>
<p>I've written before about <a href="https://shkspr.mobi/blog/2013/11/civic-hygiene/">Civic Hygiene</a> - it's the idea that we should be mindful of the ways that our technologies could be misused. The term was coined back in 2010 by the technologist Bruice Schneier</p>
<blockquote><p><a href="https://www.schneier.com/essays/archives/2010/01/us_enables_chinese_h.html">It's bad civic hygiene to build technologies that could someday be used to facilitate a police state.</a></p></blockquote>
<p>But what do we mean by that?</p>
<p>We don't want backdoors in security products - lest hackers break in or evil governments get elected. But we want a way to access our beloved ones' data after they die. It's important that we know that photos haven't been manipulated by propagandists and saboteurs. But we want to send funny memes about that politician we don't like. We don't want police stalking ex girlfriends' cars - but we want dangerous drivers prosecuted.</p>
<p>We want to be alerted about imminent threats, but don't want Governments to use that power for ill.</p>
<p>Way back in the early 2020s, I had a minor role in the UK Government's adoption of <a href="https://github.com/co-cddo/open-standards/issues/73">Common Alerting Protocol</a> the technology which powers cell-broadcast emergency alerts.</p>
<p>Even back then, one of the discussions was around whether the utility of being able to send an unavoidable push notification was worth the risk that someone would send an inappropriate message. Fresh in everyone's minds was the <a href="https://www.bbc.co.uk/news/world-us-canada-42680070">false alarm saying missiles were heading to Hawaii</a>.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/2018_Hawaii_missile_alert_cropped.jpeg" alt="Emergency alert. BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL." width="768" height="343" class="aligncenter size-full wp-image-74163">
<p>Too many safeguards means that a genuine alert doesn't get sent in time. Too few safeguards and you can blame "<a href="https://shkspr.mobi/blog/2026/08/book-review-the-field-guide-to-understanding-human-error-by-sidney-dekker/">Human Error</a>" for any mistakes.</p>
<p>I don't know which safeguards are in place for the UK's system - <a href="https://www.ofcom.org.uk/siteassets/resources/documents/about-ofcom/foi/2024/march/emergency-broadcasting?v=331069">and most details are exempt from Freedom of Information requests</a>. But it is both easy and fun to speculate on how such a system might be designed.</p>
<p>The Government generates an alert. It specifies where and when the alert should be sent. It sends that message to the network operators via a secure and private channel. Perhaps they also do some out-of-band verification like having the network operator call a pre-determined phone number to check the message's validity.</p>
<p>At which point, the operator can choose to send the message or not.</p>
<p>Or can they?</p>
<p>In August 2026, the UK government instructed network operators to send this message:</p>
<p><a href="https://www.gov.uk/alerts/14-aug-2026-2"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/fire-alert.webp" alt="Alert about fire risk in the UK." title="Screenshot courtesy of Skylar MacDonald" width="1024" height="851" class="aligncenter size-full wp-image-74164"></a></p>
<p>Did the networks <em>have</em> to send that message? If they thought it wasn't serious enough, could they have refused? As far as I can tell, the law only talks about the fact that operators can disregard "spam" laws in order to send a mass message:</p>
<blockquote><p>A relevant public communications provider (P) may, for the purpose of providing an emergency alert service, disregard the restrictions on the processing of data relating to users or subscribers set out in paragraph (2) if the conditions set out in paragraph (3) are met.</p>
<p>[…]</p>
<p>(3) The conditions are—</p>
<p>(a)P is notified by a relevant public authority that—</p>
<p>(i)an emergency within the meaning of section 1(1) of the Civil Contingencies Act 2004 has occurred, is occurring or is about to occur;</p>
<p><a href="https://www.legislation.gov.uk/uksi/2015/355/pdfs/uksi_20150355_en.pdf">Statutory Instrument 2015 No. 355</a></p></blockquote>
<p>I'm no expert, but I can't see anything in <a href="https://www.ofcom.org.uk/siteassets/resources/documents/manage-your-licence/mobile-wireless-and-broadband/cellular/licences/cellular-licence-vodafone-0249664.pdf?v=368347">the spectrum licence</a> nor in the <a href="https://www.legislation.gov.uk/ukpga/2006/36/contents">Wireless Telegraphy Act</a> which <em>compels</em> operators to process these messages.</p>
<p>The usual British way is to ask people to play nicely and threaten them with regulation if they don't.</p>
<p>Could the networks have refused to send the message about wildfires - or indeed any other message? If your least favourite politician gets their hands on the emergency alert system and tries to abuse it, would you want the networks to stand up to them?</p>
<p>What if the network refuses to send the message because they're worried alerting people about a hurricane will lower the company's profits?</p>
<p>What if armed thugs are sent in and the choice is send the message or die?</p>
<p>I don't know what the answer is here. I think most people agree that it is broadly sensible to have a way to alert the population of emergencies. There's no mass media any more, we're not all listening to a single radio channel, or reading newspapers, or even on the same social media platforms. Sometimes there are emergencies and the Government has a duty to alert people to them.</p>
<p>How would you design a system that simultaneously achieved all these goals:</p>
<ul>
<li>Rapid sending of messages</li>
<li>Careful checking of the content of messages</li>
<li>Ability to quickly target a specific geographic area</li>
<li>Inability to mistakenly send a test message</li>
<li>Requiring strong proof that the message is authentic before sending</li>
<li>Resilient enough to work after significant damage to infrastructure</li>
<li>That networks have the ability to vet and ignore</li>
<li>That networks are compelled to send</li>
<li>Which can only be used for good</li>
<li>And cannot be used for evil.</li>
</ul>
<p>In truth, <a href="https://bsky.app/profile/edent.tel/post/3mt2s2puhuk2x">having experienced fire-starters</a>, I'm not bothered about the contents of this latest message from the UK Government. Given the overstretched fire service and the imminent threat across most of the country, my personal opinion is that it is proportionate.</p>
<p>But it is easy to see why some people feel this might open the gateway to messages which, at best, are irrelevant and, at worst, are similar to the insidious propaganda which appeared on the phones of Egyptians:</p>
<blockquote><p>To every mother-father-sister-brother, to every honest citizen. Preserve this country as the nation is forever.</p></blockquote>
<p>Perhaps you can think of a way to design an alerting system which cannot be abused - but I can't.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74161&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>13</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Thoughts on visiting the Edinburgh Fringe as a newbie]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/"/>
<id>https://shkspr.mobi/blog/?p=74021</id>
<updated>2026-08-16T09:29:11Z</updated>
<published>2026-08-16T11:34:21Z</published>
<category scheme="https://shkspr.mobi/blog" term="EdFringe"/>
<summary type="html"><![CDATA[This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer. P…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/"><![CDATA[<p>This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer.</p>
<h2 id="price"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#price">Price</a></h2>
<p>Everything is too expensive. We found student accommodation which was a "mere" £220 per night. I guess that wasn't <em>too</em> exorbitant considering the gouging going on elsewhere - and it did come with a decent breakfast. It was about a 20 minute walk from the Royal Mile, with several performance venues on the way.</p>
<p>The 46 tickets we bought cost us £550 in total - which included a few donations at Free Fringe shows. So an average ticket of £12, which isn't too bad, I guess. You can certainly do things cheaper by only going to free shows and running away when they ask you to pay - but that's a dick move.</p>
<p>£20 for a single hour of stand-up feels like kind of a rip off at times - especially with the mandatory £1.50 booking fee for every ticket. Some shows are a bit cheaper, and Monday/Tuesday has 2-for-1 offers. But it's easy for a couple to spend well over a hundred quid per day seeing 3 or 4 shows.</p>
<p>Festival food and drink prices are inflated - but there's no shortage of supermarkets if you want a meal deal. Restaurants were usual city centre prices. The bars at festival venues were fully taking advantage of their captive audience, but the pubs aren't much cheaper.</p>
<h2 id="the-app"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#the-app">The App</a></h2>
<p>In theory, the app / website is good. In reality they're both a bit frustrating to use. Every time I ticked the box saying "remember my credit card details" and every time it forgot them. Both app and website frequently timed out, failed to add tickets to baskets, and were a bit shonky. The <em>one</em> thing this needs to do is reliably take my money and give it to performers - but it felt like a battle every time.</p>
<p>We missed one show because we couldn't buy a ticket in the app despite being in the queue. The door staff didn't have the ability to sell us a ticket (although some venues can) and directed us to a box office which was dealing with a bunch of people who were bemused that they couldn't pay in dollars.</p>
<p>Inexplicably, the app doesn't have the ability to see show reviews, even though they're present on the website.</p>
<p>There's a good "Nearby Now" feature which is handy when you're exhausted and don't want to trek far. By contrast, there's no easy way to see what's on near the next venue you're going to.</p>
<p>Searching for shows often returns events which are cancelled or sold out.</p>
<p>I wish it were possible to see which shows had undersold and were starting soon. I loved taking a punt on an unknown act who only had half-a-dozen people in the room. Sadly there's no way to grab last-minute deals.</p>
<p>This isn't helped by the total collapse of mobile signal in Edinburgh centre. I tried with a variety of SIMs but frequently only got a trickle of data.</p>
<h2 id="what-to-see"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#what-to-see">What To See</a></h2>
<p>The <abbr title="Fear Of Missing Out">FOMO</abbr> is real! Every show's poster makes it look amazing. The earnest performers desperately handing out leaflets for their own shows are <em>so</em> enthusiastic. Everyone you speak to in a queue has a "must see" which is probably sold out.</p>
<p>We mostly avoided seeing big names. They'll be on telly soon enough or tour down in London. I don't think that act who was big in the 1990s needs my coin as much as some up-and-comer.</p>
<p>You could easily fill a week seeing nothing but Shakespeare in a variety of styles. Or just watch middle-aged white guys have mental breakdowns on stage because they're on their 3rd divorce. Or, as it turns out, fill your boots with Heated Rivalry shows.</p>
<p>We did the tasting menu and had a little bit of everything. It was mostly pretty good with only a few duds.</p>
<h2 id="reviews"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#reviews">Reviews</a></h2>
<p>Even the worst show we saw had a couple of people who declared it the funniest thing ever five stars lol. You can't account for someone else's taste.</p>
<p>I enjoyed <a href="https://shkspr.mobi/blog/tag/EdFringe">writing my reviews</a> - and I hope they were useful to others - but you're mostly on your own when it comes to what's good. I suppose if you wait until later in the festival there will be more of a consensus about what to see.</p>
<p>My philosophy is to take a punt on basically anything that doesn't look too abhorrent. Even if it is shit, there's be something else along in a minute which will be better.</p>
<h2 id="distance"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#distance">Distance</a></h2>
<p>You'll get your 10k steps in before lunchtime - Edinburgh is a delightfully walkable city. With a bit of planning you can walk a straight line from show-to-show. We didn't plan and traipsed back and forth like the little lost tourists we were.</p>
<p>Venues are mostly well sign-posted. Again, the app is a bit crap at pointing them out, but it'll open your mapping app to navigate you there.</p>
<p>Many of the venues are in historic buildings, so don't expect lifts or escalators. Stairs all the way, baby!</p>
<h2 id="harry-potter"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#harry-potter">Harry Potter</a></h2>
<p>Edinburgh seems like an inclusive and trans-friendly city. Half the acts on the Fringe proudly stated their LGBT+ credentials and most venues we went to had gender neutral loos.</p>
<p>And then every other shop proudly boasts it is 100% definitely where JKR got the inspiration for Harry Potter. Tourists are schelpped between "Diagon Alley" and probably-the-cafe-where-she-wrote while slurping down dayglo butterbeers.</p>
<p>Truly the duality of life!</p>
<h2 id="comfort"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#comfort">Comfort</a></h2>
<p>There's an ancient Edinburgh byelaw which prohibits cushions on seats. No chair may be wide enough to accommodate anything other than the skinniest arse. It also places a moratorium on legroom.</p>
<p>Ok, some of the venues were more comfortable than others, but prepare for a bit of backache.</p>
<p>Toilets are plentiful in most venues, and theres no shortage of pubs to pop in to if you need refreshment or relief.</p>
<p>Scotland isn't known for its heat, but some of the venues desperately need air-conditioning in their foyers and auditoriums. A few were handing out free water to the swealtering punters - but probably best to bring your own</p>
<h2 id="would-i-come-here-again"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#would-i-come-here-again">Would I Come Here Again?</a></h2>
<p>Yeah! I reckon so! Probably not next year, and probably with more of a plan about which "must sees" I wanted to see.</p>
<p>Staying closer to the centre is more expensive, but might have made it easier to see some if the shows later in the night.</p>
<p>There is <em>so</em> much talent, <em>so</em> much variety, and <em>so</em> much joy in the city that it becomes rather infectious.</p>
<p>If you can afford the train fare, hotel costs, tickets, booking fees, pints, chips and all the other people desperate to stick their hands into your wallet - then it is a great adventure.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: Slags by Emma Jane Unsworth ★★★⯪☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-slags-by-emma-jane-unsworth/"/>
<id>https://shkspr.mobi/blog/?p=72687</id>
<updated>2026-06-29T19:43:11Z</updated>
<published>2026-08-15T11:34:42Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Club"/>
<category scheme="https://shkspr.mobi/blog" term="Book Review"/>
<summary type="html"><![CDATA[I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia. It reminds me of this excellent essay by Marie Le Conte about consent. What can a teenage girl…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-slags-by-emma-jane-unsworth/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/06/slags.webp" alt="Book cover featuring a teenage girl smoking." width="200" class="alignleft size-full wp-image-72688">
<p>I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia.</p>
<p>It reminds me of this excellent <a href="https://youngvulgarian.substack.com/i/152315586/a-column">essay by Marie Le Conte about consent</a>. What can a teenage girl consent to? What will fuck her up for years to come? What if she doesn't mind being a <em>little</em> fucked up?</p>
<p>The prose is amazing, the plotting perfectly paced, and the denouement satisfying - with lots of retrospectives "Oh! I get it now"s.</p>
<p>Despite the hectic and hilarious story, I still felt a little sordid reading it. There's a streak of sadness running through it, intertwined with some unbearably heartbreaking poetry.</p>
<blockquote><p>It’s always raining and there’s nothing to do except dream and they don’t even give you much time to do that with all the coursework.</p></blockquote>
<p>It is entertaining and fun - but you need a strong stomach and a casual disregard for the overall happiness of your protagonists.</p>
<p>One note - there are a few odd / broken styles in the ePub. Nothing too disruptive, but some passages have a slightly smaller font size for no discernable reason.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=72687&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Edinburgh Fringe: Target Audience ★★★★★]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-target-audience/"/>
<id>https://shkspr.mobi/blog/?p=74018</id>
<updated>2026-08-14T18:10:20Z</updated>
<published>2026-08-14T18:45:41Z</published>
<category scheme="https://shkspr.mobi/blog" term="comedy"/>
<category scheme="https://shkspr.mobi/blog" term="EdFringe"/>
<category scheme="https://shkspr.mobi/blog" term="Theatre Review"/>
<summary type="html"><![CDATA[Easily the best show I've seen at the Fringe. For plot-related reasons, a television company asks a literary genius to create a "pro-weapons sitcom". It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night. All four of the cast are spectacular. Turning the…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-target-audience/"><![CDATA[<p>Easily the best show I've seen at the Fringe.</p>
<p>For plot-related reasons, a television company asks a literary genius to create a "pro-weapons sitcom".</p>
<p>It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night.</p>
<p>All four of the cast are spectacular. Turning the sometimes-stock characters into powerful avatars. The amoral Zuckerbergian horror of data driven decision making is the perfect manure in which to grow comedy roses.</p>
<p>It stands well against any classic farce and I hope it tours until the end of the world.</p>
<p>A special shout out to the Pleasance Above for being the most comfortable venue in Edinburgh! Raked auditorium, cushioned seats, and air conditioning all make for a delightful theatrical experience.</p>
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<title type="text">Terence Eden’s Blog</title>
<subtitle type="text">Regular nonsense about tech and its effects 🙃</subtitle>
<updated>2026-09-08T09:42:04Z</updated>
<rights>© Terence Eden. 🄯 CC BY. See https://shkspr.mobi/blog/copyright-and-copyleft/</rights>
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<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[ActivityPub - Is it worth defending against replay attacks and message/signature time skew?]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/" />
<id>https://shkspr.mobi/blog/?p=74622</id>
<updated>2026-09-08T09:42:04Z</updated>
<published>2026-09-08T11:34:51Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot" /><category scheme="https://shkspr.mobi/blog" term="ActivityPub" /><category scheme="https://shkspr.mobi/blog" term="http" /><category scheme="https://shkspr.mobi/blog" term="security" />
<summary type="html"><![CDATA[Here's a problem that I've found with ActivityBot - my little ActivityPub server. Sometimes it receives messages which were originally sent months ago. Why does that happen and is it risky to accept and process them? My tl;dr is that it probably isn't worth worrying about. But I'd love someone to tell me why I'm wrong. Here's my thinking: Table of ContentsCausesIs that a problem?What are we…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/"><![CDATA[<p>Here's a problem that I've found with <a href="https://gitlab.com/edent/activity-bot/">ActivityBot</a> - my little ActivityPub server. Sometimes it receives messages which were originally sent <em>months</em> ago. Why does that happen and is it risky to accept and process them?</p>
<p>My tl;dr is that it <em>probably</em> isn't worth worrying about. But I'd love someone to tell me why I'm wrong.</p>
<p>Here's my thinking:</p>
<p></p><nav role="doc-toc"><menu><li><h2 id="table-of-contents"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#table-of-contents">Table of Contents</a></h2><menu><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes">Causes</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem">Is that a problem?</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against">What are we trying to protect against?</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together">Putting it all together</a></li><li><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it">No! You're wrong and I can prove it!</a></li></menu></li></menu></nav><p></p>
<h2 id="causes"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes">Causes</a></h2>
<p>All ActivityPub messages should have a "published" timestamp in their body. Some will have an "updated" timestamp. That tells you, unsurprisingly, when the message is alleged to have been originally published or updated. That time might be very different to the time you receive the message.</p>
<p>There are, I think, three different reasons why a server might receive a message which has an out-of-date timestamp.</p>
<p>The first is that sometimes servers are just slow. Processing thousands of messages at the same time means that some of those messages take a while to send. <a href="https://shkspr.mobi/blog/2023/09/how-far-did-my-post-go-on-the-fediverse/">ActivityPub is one big chain-mail</a> so it can take several minutes for a message to be sent to all your followers.</p>
<p>Similarly, your server might be slow. If it doesn't acknowledge receipt of a message, the original server will try sending it again. Sometimes that can take a while.</p>
<p>Finally, some servers take a relaxed view of standards. They send an update to an old message but keep the original publication date. Ideally, they'd use an "updated" timestamp but quite often they don't.</p>
<p>For the purposes of checking the legitimacy of the message, <strong>you do not need to check when a message says it was published or updated</strong>. You might want to check it isn't an <em>obviously</em> bogus date like far in the future or impossibly far in the past - but that's up to you.</p>
<p>It is normal that your server receives messages which appear to have been published at a totally different time from now.</p>
<h2 id="is-that-a-problem"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem">Is that a problem?</a></h2>
<p><em>Probably</em> not.</p>
<p>As described above, there are various reasons why a message may be delayed in transit - or may appear to come from the distant past.</p>
<p>What we <em>can</em> check is when the message was cryptographically signed by the sending server. This is independent of its published or updated timestamp.</p>
<p>HTTP requests to your server will have a <code>date</code> header which looks like <code>Tue, 01 Sep 2026 15:54:21 GMT</code> - this is in the slightly peculiar and Anglocentric <a href="https://www.rfc-editor.org/info/rfc5322/#section-3.3">RFC 5322 format</a>.</p>
<p>New style RFC 9421 headers will also have a <code>signature-input</code> header which will contain something like <code>created=1788278061</code>. That uses the slightly obscure <a href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16">UNIX / POSIX time</a> which counts seconds since the "Epoch" of 1st January 1970.</p>
<p>If you <a href="https://www.epochconverter.com/">convert the UNIX time</a> to something more modern, you should get an <em>identical</em> value to the <code>date</code> header.</p>
<p>But that isn't always the case. For example, <a href="https://www.rfc-editor.org/rfc/rfc9421.html#:~:text=Tue%2C%2020%20Apr%202021%2002%3A07%3A55%20GMT,-Content%2DType">the RFC 9421 standard gives this example</a>:</p>
<pre><code class="language-_">Date: Tue, 20 Apr 2021 02:07:55 GMT
"@signature-params": ("@method" "@authority" "@path" \
"content-digest" "content-length" "content-type")\
;created=1618884473;keyid="test-key-rsa-pss"
</code></pre>
<p>Converting <code>1618884473</code> to normal time gives Tue, 20 Apr 2021 02:07:<strong>53</strong> - a two second difference.</p>
<p>If the <code>date</code> and <code>created</code> values differ significantly - that may indicate that the message is untrustworthy. Or that there was a delay between the signing and the sending.</p>
<p>The spec says:</p>
<blockquote><p>The Date header field value represents the timestamp of the HTTP message. However, the creation time of the signature itself is encoded in the created signature parameter. These two values can be different, depending on how the signature and the HTTP message are created and serialized. Applications processing signatures for valid time windows should use the created signature parameter for such calculations. An application could also put limits on how much skew there is between the Date field and the created signature parameter, in order to limit the application of a generated signature to different HTTP messages.</p>
<p><a href="https://www.rfc-editor.org/rfc/rfc9421.html#section-7.2.4">7.2.4. Choosing Signature Parameters and Derived Components over HTTP Fields</a></p></blockquote>
<p>But, of course, it doesn't tell you how much skew is problematic. It's up to you how much skew you're prepared to accept.</p>
<p>So that's the difference between the sent time and the signed time. The next time to check is your own. As we've discussed, sometimes servers are slow sending things out. Would you accept a request that was signed five minutes ago? Five days ago? Five months ago? What amount of difference is dangerous?</p>
<p>Here's what various services and sages have to say:</p>
<h3 id="mastodon"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#mastodon">Mastodon</a></h3>
<blockquote><p>The request contains a Date header. Compare it with current date and time within a reasonable time window to prevent replay attacks.</p>
<p><a href="https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/">How to make friends and verify requests</a></p></blockquote>
<p>What is "reasonable"? The <a href="https://github.com/mastodon/mastodon/blob/89bc0eb42609463d4b11e1604dacc37332a0f5ab/app/lib/signed_request.rb#L5">source code</a> suggests one hour.</p>
<h3 id="grishka"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#grishka">Grishka</a></h3>
<blockquote><p>Time in the Date header must differ from the recipient server’s clock by no more than 30 seconds</p>
<p><a href="https://grishka.me/blog/activitypub-from-scratch/">A bare-minimum ActivityPub server from scratch</a></p></blockquote>
<h3 id="evan-prodromou"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#evan-prodromou">Evan Prodromou</a></h3>
<blockquote><p><code>static #maxDateDiff = 5 * 60 * 1000 // 5 minutes</code></p>
<p><a href="https://github.com/evanp/activitypub-bot/blob/main/lib%2Fhttpsignatureauthenticator.js#L8">activitypub-bot</a></p></blockquote>
<h3 id="swicg"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#swicg">SWICG</a></h3>
<blockquote><p>The standards don't give a concrete time window to use for this comparison. In practice, an hour plus a few minutes buffer in either direction may be a good value, to account for both clock skew and differences in time zone/daylight savings time configuration across systems.</p>
<p><a href="https://swicg.github.io/activitypub-http-signature/#how-to-verify-a-signature">How To Verify a Signature</a></p></blockquote>
<h3 id="others"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#others">Others</a></h3>
<p>Without naming names, it looks like a bunch of popular servers don't check whether there's a significant difference between the date the request was signed and the date it was received.</p>
<h3 id="summary"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#summary">Summary</a></h3>
<p>Various documents and implementations recommend anything between 30 seconds to "a bit more than 60 minutes". Or they just ignore any date difference.</p>
<p>What's the right answer? What happens if the signed date is significantly different from the current date?</p>
<h2 id="what-are-we-trying-to-protect-against"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against">What are we trying to protect against?</a></h2>
<p>Replay Attacks. Suppose someone is listening to the communications between the sending server and your server. They copy the message that is sent to you. Later they send it again!</p>
<p>At this point, you might be thinking "so what?" and… I'm inclined to agree with you!</p>
<p>What's the worst that could happen if you received the same message multiple times? Two things that I can think of.</p>
<p>Firstly, it might <em>not</em> be the same message. It is possible to send a new message but with old headers. An attacker could make someone post "I hate Taylor Swift" against their will and watch as legions of fans disembowel the victim.</p>
<p>Except, I don't think this is likely. The signature in the header contains a hash of the message being sent. If you are properly validating the signature, a changed message will have a different hash from the one in the original message. You don't need to check timestamps, you just need to check if the hashes match.</p>
<p>Secondly, <a href="https://www.freecodecamp.org/news/idempotence-explained">idempotence</a>. That's a fancy word for "pressing the button multiple times should only result in one action".</p>
<p>What happens if a user appears to send you multiple "like" messages for a single post? You only record one like.</p>
<p>What if they send multiple messages with the same content? Well, each will have a unique ID in the message - so you only post it once.</p>
<p>What if they send multiple <em>anythings</em>? I can't think of any ActivityPub action which would not be idempotent.</p>
<p>About the worst thing I can think of is this:</p>
<ul>
<li>Alice sends a message to you saying "I want to follow Bob".</li>
<li>Mallory intercepts this message.</li>
<li>You record Alice is now following Bob.</li>
<li>Alice sends a message to you saying "I want to <em>unfollow</em> Bob".</li>
<li>You record the severed relationship.</li>
<li>Mallory replays the original follow message.</li>
<li>You record Alice is now following Bob.</li>
</ul>
<p>It's also possible the following could happen:</p>
<ul>
<li>Alice posts a message saying "I love The Beatles".</li>
<li>You record Alice's message and display it on the timeline.</li>
<li>Alice updates her post to say "I love the Rolling Stones".</li>
<li>Mallory intercepts this message.</li>
<li>You record Alice's updated message and display the new version on the timeline.</li>
<li>Alice updates her post yet again to say "I love the Spice Girls".</li>
<li>You record Alice's updated message and display the new version on the timeline.</li>
<li>Mallory replays the original update message.</li>
<li>You now display that Alice loves the Stones rather than Spice Girls.</li>
</ul>
<p>Perhaps the same can happen with like/unlike, block/unblock, boost/unboost.</p>
<p>But none of that is significantly prevented by checking the date.</p>
<p>Ultimately, it is up to your sever to check the unique ID of each message and refuse to action any repeated messages. You may not want to trust the unique ID which is sent with the message. If that's the case, you can calculate your own - perhaps using a hash of the contents, the signature, or some other process which will generate an ID based on the message.</p>
<h2 id="putting-it-all-together"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together">Putting it all together</a></h2>
<p>Here's what you need to do to prevent replay attacks:</p>
<ol>
<li>Independently calculate the hash of the message received.</li>
<li>Validate that your calculated hash matches the hash sent in the message's HTTP headers.
<ul>
<li>If not, this is a potential replay attack and the message must be ignored.</li>
</ul></li>
<li>Verify that the signature received in the message's HTTP headers includes the message hash and is cryptographically valid.
<ul>
<li>If not, the signature is invalid and the message must be ignored.</li>
</ul></li>
<li>Has the received message's unique ID already been processed?
<ul>
<li>If so, refuse to process it again.</li>
</ul></li>
</ol>
<p>I don't see what checking the timestamp of the HTTP signature has to do with anything. Someone who has access to the original messages and their headers could send them milliseconds after the original delivery.</p>
<p>I think it is probably <em>pragmatic</em> to give messages 60ish minutes grace before dropping them. Delays happen, but anything more significant than an hour <em>might</em> indicate a attack. But, equally, might just mean that the Internet is having a slow day.</p>
<p>If you are correctly checking signatures and hashes, I don't think you need to worry about skew between signature date and delivery date.</p>
<h2 id="no-youre-wrong-and-i-can-prove-it"><a href="https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it">No! You're wrong and I can prove it!</a></h2>
<p>Please tell me where I have erred! Stick a comment in the box or drop me an email. If I've made a massive or subtle mistake, I'd love to know what.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74622&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[The purpose of DNS is to spread scams]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/" />
<id>https://shkspr.mobi/blog/?p=74588</id>
<updated>2026-09-05T17:12:13Z</updated>
<published>2026-09-06T11:34:20Z</published>
<category scheme="https://shkspr.mobi/blog" term="ICANN" /><category scheme="https://shkspr.mobi/blog" term="internet" /><category scheme="https://shkspr.mobi/blog" term="scam" /><category scheme="https://shkspr.mobi/blog" term="spam" /><category scheme="https://shkspr.mobi/blog" term="tld" /><category scheme="https://shkspr.mobi/blog" term="web" />
<summary type="html"><![CDATA[I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people …]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/"><![CDATA[<p>I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak</p>
<p>You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people don't. They hastily visit the site, tap in their credit card details, give it their mother's maiden name, confirm address, upload a nude selfie, and only then realise that they've been had.</p>
<p>The Internet works at pretty close to the speed of light. You can register a .uk domain and a minute later it's accessible from the other side of the planet. Brilliant for users who want to quickly launch a website. Also brilliant for abusers who want to launch a spam campaign.</p>
<p>By the time enough people have reported the scammers' domain as suspicious, it is too late. In the time it takes for a registrar to disable the domain, or for its name to make its way to the <a href="https://safebrowsing.google.com/">Safe Browsing List</a>, a million messages have already been sent and enough people have handed over their details.</p>
<p>We're told that "<a href="https://en.wikipedia.org/wiki/The_purpose_of_a_system_is_what_it_does">the purpose of a system is what it does</a>". At the moment, the Domain Name System's purpose seems to be a vector for criminals to run scams on people at a terrifyingly high rate.</p>
<h2 id="how-big-is-this-problem"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#how-big-is-this-problem">How big is this problem?</a></h2>
<p>BIG!</p>
<p>There's a great blog post by Andrew Campling which reports on this startling claim:</p>
<blockquote><p>The study found that at least 10% of all new gTLD domain names registered during the year had subsequently appeared on security blocklists by the time of analysis. It estimated that, taking account of subsequent blocklisting and associated domains not themselves blocklisted, the share of names registered by malicious actors <strong>may be closer to 20%</strong>.</p>
<p><a href="https://labs.ripe.net/author/andrew_campling/dns-abuse-and-criminal-infrastructure-beyond-definitions-and-blocklists/">DNS Abuse and Criminal Infrastructure: Beyond Definitions and Blocklists</a> (emphasis added)</p></blockquote>
<p>That links to a presentation by Interisle which contains some rather shocking statistics (<a href="https://www.icann.org/en/blogs/details/looking-beyond-the-numbers-understanding-malicious-domain-registration-data-10-08-2026-en">albeit with disputed methodology</a>). It looks at <em>generic</em> Top Level Domains (gTLD) - those are things like .com and .fun rather than country code TLDs (ccTLD) like .uk and .de.</p>
<p>It says 85 million new registrations of gTLDs were made in 2025. Of those 8.5 million were added to blocklists by May 2025. It reckons that a 10% abuse rate is the likely floor for these numbers and it's probably closer to 20%. One in five newly registered domains with a gTLD are scams. That's a bloody crisis.</p>
<p>13 TLDs had more than 50% of their registrations blocklisted.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/gTLDs.webp" alt="Table listing the top 13 generic Top-Level Domains (gTLDs) with the highest percentage of blocklisted, malicious new domains created in 2025. Ranked from highest to lowest blocklist percentage, top entries include .LOCKER (72.9%), .LGBT (72.2%), and .TOWN (70.2%). The table detail includes TLD operators, registration totals, and specific malicious domain metrics." width="1162" height="954" class="aligncenter">
<p>I can understand why .bid and .loan are popular with scammers. But why .mobi?! What did I ever do to you, eh?</p>
<p>Who are the scammers registering these through?</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/registrars.webp" alt="List of registrars. NameCheap, Gname, Dynadot, NameSilo, GoDaddy." width="910" height="390" class="aligncenter">
<p>Ah, our old friends at NameCheap. See <a href="https://shkspr.mobi/blog/2021/05/why-do-scammers-love-namecheap/">Why do scammers love NameCheap?</a></p>
<p>If those five registrars had more effective policies, it might significantly dent the scammers' ability to ply their devious wares. Or they might just move on to other registrars.</p>
<p>As the report points out:</p>
<blockquote><p>suspension rates for blocklisted domains were 7.4% to 16.3%.</p></blockquote>
<p><a href="https://interisle.net/s/FullReport_MaliciousRegistrationsintheDomainNameMarket_2026_rev.pdf">The full report is on the Interisle website</a>.</p>
<h2 id="what-can-be-done"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-can-be-done">What can be done?</a></h2>
<p>I don't know.</p>
<p>In the first instance, it might make sense for registrars to do strong Know Your Customer (KYC) checks on anyone buying a domain. But that stops anyone who wants to anonymously register <code>I-Hate-Nintendo.whatever</code> without risking the wrath of Intellectual Property lawyers.</p>
<p>Also, criminals have access to stolen money and stolen cards. They can convince a hapless mule to register a domain on the criminals' behalf.</p>
<p>Registrars could ask for an escrow payment. Pay €9 for the domain name put €900 in escrow. If your domain appears on a blocklist within the year, you forfeit the money. Criminals with stolen funds are unlikely to care but it would probably put off lots of people from getting a new domain.</p>
<p>There are various banned words and phrases depending on the TLD. For example, <a href="https://shkspr.mobi/blog/2024/07/ss-tld-opening-for-direct-registrations/">South Sudan</a> has a list of political words which they don't want associated with their .ss ccTLD.</p>
<p>But if one gTLD bans a word, a different one might not. A scammer doesn't care if the gTLD is .arse or .elbow - they just want the start of the domain to look legitimate.</p>
<p>Some registrars have strings that they don't allow. In fairness to NameCheap, when I tried to register <code>dwp-payments-gov-uk.pizza</code> it told me that domain was banned. It wouldn't let me get any gTLD with that name.</p>
<p>But all it takes is one registrar to be slightly lax and the scammers get through. Increasing the complexity of the rules is also a hell of a burden on smaller registrars.</p>
<p>Besides, it's pretty easy to get a generic enough looking domain and stick the confusing bit on a subdomain. Here are a clutch mentioned in the report:</p>
<ul>
<li><code>https://gov.uk-dwpaph.bond/uk/</code></li>
<li><code>https://gov.uk-dwpcjh.bond/uk/</code></li>
<li><code>https://gov.uk-dwpclc.bond/uk</code></li>
<li><code>https://gov.uk-dwpclw.bond/uk</code></li>
<li><code>https://gov.uk-dwpclj.bond/uk/</code></li>
</ul>
<p>Perhaps there ought to be a delay before a new domain goes live to allow people to object to it? That would give governments, banks, delivery companies, and a dozen more "important" organisations a right to veto any "dodgy" looking domain.</p>
<p>But suppose someone wants to register <code>gov-uk-stole-my-horse.horse</code> to protest the government's cruel policy of stealing horses - is that a legitimate use of a domain? What if the Darwin Pensioner Divas - a group of elderly singers - want to take payments for their new album of goth/punk covers, can the DPD delivery company veto <code>dpd-payments.music</code>?</p>
<p>Do we want a domain name system where powerful companies control exactly which domains we can register? If I have an idea for a domain on a Friday night do I have to wait until Monday before it can be launched? Are those companies realistically able to parse millions of domains per year and have a low false-positive rate?</p>
<p>All of these things are possible - but all of them come with an impact on legitimate users. To be clear, I don't know what the right answer is.</p>
<h2 id="what-is-icann-doing-about-it"><a href="https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-is-icann-doing-about-it">What is ICANN doing about it?</a></h2>
<p>Lots! It has been a few years since I've been to an ICANN meeting, but even back then the topic of abuse was high on the agenda. They appear to be looking at ways to coordinate abuse reports between various entities, along with some other policies which should hopefully work.</p>
<p>There are two salient points from <a href="https://hosted-files.sched.co/icann86/b3/TRANSC_I86SQV_Mon08June2026__GNSO-DNS%20Abuse%20Mitigation%20PDP%201%20%281%20of%204%29-en.pdf">one of the discussions held at the recent meeting</a></p>
<blockquote><p>If anybody thinks that in our current age of AI and as we move into different kinds of computing, DNS abuse is going to numerically stay steady and we will have a downward effect on that baseline 2027 number. I'm not sure that that's an accurate assumption. I think it's going to be the other thing, which is […] it's going to be easier to abuse the DNS.</p></blockquote>
<p>And</p>
<blockquote><p>Abusers are going to abuse because it's just too lucrative, because no matter what we do, they will find the way to make profit off of that, and will try to circumvent everything that we do. That is not a reason not to do it, though.</p></blockquote>
<p>Quite!</p>
<p>As I said, I don't know the answer to this. What I do know is, much like <a href="https://shkspr.mobi/blog/2025/08/is-it-possible-to-allow-sideloading-and-keep-users-safe/">Android's app ecosystem being a haven for scammers</a>, DNS is facing a crisis. When trust in a system goes, only chaos follows.</p>
<p>I don't want to live in a world where I have to show my passport and pay thousands of pounds to register a domain which is only available after being vetted by private interests. But I also don't want to live in a world where scammers have effectively no deterrent from abusing millions of people.</p>
<p>The purpose of a system is what it does. I hope DNS's purpose can become less dangerous while still remaining open.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74588&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>8</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: The Passing of the Dragon and Other Stories by Ken Liu ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/book-review-the-passing-of-the-dragon-and-other-stories-by-ken-liu/" />
<id>https://shkspr.mobi/blog/?p=74686</id>
<updated>2026-09-05T09:22:57Z</updated>
<published>2026-09-05T11:34:47Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review" /><category scheme="https://shkspr.mobi/blog" term="NetGalley" /><category scheme="https://shkspr.mobi/blog" term="Sci Fi" />
<summary type="html"><![CDATA[This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured. What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/book-review-the-passing-of-the-dragon-and-other-stories-by-ken-liu/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/09/9781035929306.webp" alt="Book cover." width="200" class="alignleft">
<p>This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured.</p>
<p>What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a downtown art gallery, the next in the ice-rings of a far-off planet. The creeping feeling of senescence haunts the reader as they flit from story to story.</p>
<p>Much like his full-length novel <a href="https://shkspr.mobi/blog/2025/09/book-review-all-that-we-see-or-seem-by-ken-liu/">All That We See or Seem</a>, Liu has an incredible knack for tapping in to modern fears and weaving tall tales around them. There's a tenderness in all his character - even when a couple of the stories go nowhere, it is still pleasant to spend time in the worlds he has created.</p>
<p>It is, perhaps, missing a cohesive theme - the dragons come and go throughout the stories. Nevertheless, a compelling work chock full of fantastical ideas.</p>
<p>If you're in the mood for a wide and varied selection of stories, this is well worth picking up.</p>
<p>Many thanks to NetGalley for the review copy. Passing of the Dragon is available to buy now.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74686&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[A reasonably practical guide to validating RFC 9421 HTTP Signatures for ActivityPub in PHP]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/" />
<id>https://shkspr.mobi/blog/?p=74429</id>
<updated>2026-09-04T13:36:29Z</updated>
<published>2026-09-03T11:34:12Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot" /><category scheme="https://shkspr.mobi/blog" term="ActivityPub" /><category scheme="https://shkspr.mobi/blog" term="mastodon" /><category scheme="https://shkspr.mobi/blog" term="php" /><category scheme="https://shkspr.mobi/blog" term="webdev" />
<summary type="html"><![CDATA[If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers. This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild. Shut Up And Show Me The Code! OK, wow, no…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/"><![CDATA[<p>If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers.</p>
<p>This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild.</p>
<h2 id="shut-up-and-show-me-the-code"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#shut-up-and-show-me-the-code">Shut Up And Show Me The Code!</a></h2>
<p>OK, wow, no need to be a dick about it! Here's how I validated a real signature that my server received. This requires PHP 8.4 or newer.</p>
<pre><code class="language-php">$verified = openssl_verify(
data: '"@method": POST
"@target-uri": https://example.viii.fi/inbox
"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
"@signature-params": ("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"',
signature: base64_decode( "sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==" ),
public_key: "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\n3QIDAQAB\n-----END PUBLIC KEY-----\n",
algorithm: "sha256"
);
echo $verified;
</code></pre>
<p>Copy and paste that into PHP and you should see that <code>$verified</code> is true.</p>
<h2 id="now-explain-the-code"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#now-explain-the-code">NOW EXPLAIN THE CODE</a></h2>
<p>Say please.</p>
<h2 id="please"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#please">PLEASE!!!</a></h2>
<p>Along with the message sent to your server, you will have received HTTP headers like this:</p>
<pre><code class="language-_">content-digest: sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
signature: sig1=:sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==:
signature-input: sig1=("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"
</code></pre>
<p>The <code>signature-input</code> tells you how to construct a "Signature Base". You have to build a text string which places the various components in the order specified and separated with a newline:</p>
<pre><code class="language-_">"@method": POST
"@target-uri": https://example.viii.fi/inbox
"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:
"@signature-params": ("@method" "@target-uri" "content-digest");created=1787780262;keyid="https://mastodon.social/users/Edent#main-key"
</code></pre>
<p>Where <code>@method</code> is the HTTP method used to send data to your server (usually <code>GET</code> or <code>POST</code>), and <code>@target-uri</code> is the URl the message was sent to (usually your inbox).</p>
<p>The <code>publicKey</code> is slightly trickier. As you can see, the <code>signature-input</code> ends with <code>keyid="https://mastodon.social/users/Edent#main-key</code></p>
<p>If you make a signed request to that URl, you'll get back an ActivityPub Actor document. It will look something like this:</p>
<pre><code class="language-json">{
"@context": [
"https://www.w3.org/ns/activitystreams",
"https://w3id.org/security/v1",
],
"id": "https://mastodon.social/users/Edent",
"webfinger": "Edent@mastodon.social",
"type": "Person",
"name": "Terence Eden",
"publicKey": {
"id": "https://mastodon.social/users/Edent#main-key",
"owner": "https://mastodon.social/users/Edent",
"publicKeyPem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\n3QIDAQAB\n-----END PUBLIC KEY-----\n"
},
</code></pre>
<p>The <code>publicKeyPem</code> is the string you need. There's no need to convert the <code>\n</code> to literal newlines.</p>
<h2 id="is-that-it"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#is-that-it">Is that it?</a></h2>
<p>Not quite! All we've done so far is verify the headers. It is possible that these are genuine headers but attached to a fraudulent body.</p>
<p>This takes us back to the header <code>"content-digest": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:</code></p>
<p>That says that the body of the message sent has a Base64 encoded SHA256 hash of <code>tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=</code>.</p>
<p>To calculate your own content digest in PHP:</p>
<pre><code class="language-php">$input = file_get_contents( "php://input" );
$digestCalculated = base64_encode(
hash(
algo: "sha256",
data: $input,
binary: true
)
);
</code></pre>
<p>Does your digest match the one sent along with the headers? If not, something dodgy is going on.</p>
<h2 id="putting-it-all-together"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#putting-it-all-together">Putting it all together</a></h2>
<p>The steps are:</p>
<ol>
<li>Get the headers.</li>
<li>Get the body.</li>
<li>From the headers' <code>content-digest</code> extract the algorithm and hash.</li>
<li>Using the body, calculate your own hash using the algorithm from <code>content-digest</code>.</li>
<li>Does your hash match the sent hash? If not, stop. If so, proceed.</li>
<li>From the headers' <code>signature</code> extract the base64 encoded signature.</li>
<li>From the headers' <code>signature-input</code> extract the signature-input string.</li>
<li>From the signature-input string extract the order of the Signature Base.</li>
<li>Construct the Signature Base.</li>
<li>From the signature-input string extract the keyid.</li>
<li>Get the Public Key from the keyid.</li>
<li>Use <code>openssl_verify()</code> to verify the Signature Base and the base64 decoded signature, against the Public Key using SHA256.</li>
</ol>
<p>Note, <a href="https://docs.joinmastodon.org/spec/security/#http-message-signatures">Mastodon <em>only</em> uses SHA256</a>. I think it should explicitly say which algorithm it is using <a href="https://github.com/mastodon/mastodon/issues/29905#issuecomment-5440336919">and have raised the issue</a>.</p>
<h3 id="in-code-form"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#in-code-form">In Code Form</a></h3>
<p>This is how you do it in PHP. Please read this carefully as there are some hard-coded assumptions.</p>
<pre><code class="language-php"><?php
// Validate the Digest.
// It is the hash of the raw input string, in binary, encoded as base64.
// The format is content-digest => <algorithm>=:<base64 encoded hash>:
$digestString = $headers["content-digest"];
// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.
$digestData = explode( separator: "=", string: $digestString, limit: 2 );
// Hashes are in lowercase, but have a `-` in their name.
// This is not what hash_algos() expects.
$digestAlgorithm = str_replace( search: "-", replace: "", subject: $digestData[0] );
// The hash is surrounded by `:` characters.
$digestHash = str_replace( search: ":", replace: "", subject: $digestData[1] );
// Check if the hash algorithm is one known about to PHP.
// If not, reject and record an error.
if ( !in_array( needle:$digestAlgorithm, haystack: hash_algos() ) ) {
return false;
}
// Manually calculate the digest based on the data sent.
$digestCalculated = base64_encode( hash( algo: $digestAlgorithm, data: $input, binary: true ) );
// Does our calculation match what was sent?
if ( !( $digestCalculated == $digestHash ) ) {
return false;
}
// The signature format is signature => <signature name>=:<base64 encoded hash>:
$signatureString = $headers["signature"];
// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.
$signatureData = explode( separator: "=", string: $signatureString, limit: 2 );
$signatureName = $signatureData[0];
// The signature is surrounded by `:` characters.
$signatureB64 = str_replace( search: ":", replace: "", subject: $signatureData[1] );
// The signature-input format is complicated!
$signatureInputString = $headers["signature-input"];
// Get the parameters. Assume there is only one signature.
$signatureParamsString = explode( separator: "=", string: $signatureInputString, limit: 2 )[1];
// Get the different elements of the signature.
$signatureInputData = explode( separator: ";", string: $signatureInputString );
// Construct the data.
$signatureInput = [];
foreach( $signatureInputData as $signatureInputParts ) {
$partsData = explode( separator: "=", string: $signatureInputParts );
// Strip quotes from keyid and parentheses from sig1.
if ( "keyid" == $partsData[0] ) {
$partsData[1] = str_replace( search: "\"", replace: "", subject: $partsData[1] );
}
if ( $signatureName == $partsData[0] ) {
$partsData[1] = str_replace( search: ["(", ")"], replace: "", subject: $partsData[1] );
}
$signatureInput[ $partsData[0] ] = $partsData[1] ;
}
$signatureStructure = $signatureInput[$signatureName];
$signatureKeyID = $signatureInput["keyid"];
// Remove quotes.
$signatureStructure = str_replace( search: "\"", replace: "", subject: $signatureStructure );
$signatureStructureData = explode( separator: " ", string: $signatureStructure );
// https://www.rfc-editor.org/info/rfc9421/#section-2.5
$signatureBase = "";
foreach ( $signatureStructureData as $signatureStructureParts ) {
if ( "@method" == $signatureStructureParts ) {
// https://www.rfc-editor.org/info/rfc9421/#name-method
$signatureBase .= "\"@method\": " . $_SERVER["REQUEST_METHOD"] . "\n";
}
if ( "@target-uri" == $signatureStructureParts ) {
// https://www.rfc-editor.org/info/rfc9421/#section-2.2.2
// Change the domain name to your own.
$signatureBase .= "\"@target-uri\": https://EXAMPLE.COM" . $_SERVER["REQUEST_URI"] . "\n";
}
if ( "content-digest" == $signatureStructureParts ) {
$signatureBase .= "\"content-digest\": $digestString\n";
}
}
// https://victoronsoftware.com/posts/http-message-signatures/#how-the-signature-is-created
$signatureBase .= "\"@signature-params\": $signatureParamsString";
// Get the signing user's public key.
// This is usually in the form `https://example.com/user/username#main-key`
// This is to differentiate if the user has multiple keys.
// This may need to be a signed request. You will need to write your own getDataFromURl() function to get the sending user's key.
$userData = getDataFromURl( $signatureKeyID );
$publicKey = $userData["publicKey"]["publicKeyPem"];
// Verify the request
$verified = openssl_verify(
data: $signatureBase,
signature: base64_decode( $signatureB64 ),
public_key: $publicKey,
algorithm: $digestAlgorithm
);
// Convert the result to boolean.
if ( $verified === 1 ) {
$verified = true;
} elseif ( $verified === 0 ) {
$verified = false;
} else {
$verified = null;
}
return $verified;
</code></pre>
<h2 id="further-reading"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#further-reading">Further Reading</a></h2>
<ul>
<li><a href="https://www.rfc-editor.org/info/rfc9421/">RFC 9421 HTTP Message Signatures</a></li>
<li><a href="https://victoronsoftware.com/posts/http-message-signatures/">Understanding HTTP message signatures: A developer's guide</a></li>
<li><a href="https://www.otoroshi.io/docs/tutorials/http-message-signatures-rfc9421/">Sign and verify HTTP messages (RFC 9421)</a></li>
<li><a href="https://darutk.medium.com/verification-of-http-message-signatures-501bbdc7dfec">Verification of HTTP Message Signatures</a></li>
<li><a href="https://github.com/macgirvin/HTTP-Message-Signer">HTTP-Message-Signer in PHP</a></li>
</ul>
<h2 id="thanks-to-nlnet"><a href="https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#thanks-to-nlnet">Thanks to NLnet</a></h2>
<p>This blog post was funded in part by the work I'm doing for my NLnet NGI0 grant. Thanks!</p>
<p><a href="https://nlnet.nl/project/ActivityBot/"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp" alt="NLnet logo." width="900" height="200" class="aligncenter"></a></p>
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<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: ActivityPub by Evan Prodromou ★★★★⯪]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/09/book-review-activitypub-by-evan-prodromou/" />
<id>https://shkspr.mobi/blog/?p=74414</id>
<updated>2026-08-31T18:53:48Z</updated>
<published>2026-09-01T11:34:18Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityPub" /><category scheme="https://shkspr.mobi/blog" term="Book Review" />
<summary type="html"><![CDATA[As part of my grant from NLnet to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text. Sometimes you just want one book which collates all the info and…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/09/book-review-activitypub-by-evan-prodromou/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/activitypub.jpg" alt="Book cover with a parrot on it." width="200" class="alignleft">
<p>As part of <a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/">my grant from NLnet</a> to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text.</p>
<p>Sometimes you just want one book which collates all the info and presents it in a consistent format. This is <em>nearly</em> that book.</p>
<p>Evan Prodromou has the unenviable task of making the whole ecosystem easy to understand. Thankfully he does that well. Things are logically laid out, there are comprehensive descriptions of even the most obscure parts of the spec, and it builds up nicely from the fundamentals. Oh, it's also surprisingly light-hearted.</p>
<blockquote><p>This principle is so important and long-winded that web architects have given it an acronym, HATEOAS. (We often pronounce it “HATE-ee-OH-us,” which sounds like a breakfast cereal nobody wants to eat. This is one reason web architects aren’t allowed to name breakfast cereals.)</p></blockquote>
<p>There's an excellent checklist for all the steps needed when building a minimal ActivityPub server.</p>
<p>As with all O'Reilly books, it is a beautifully typeset ePub. Even better, it was supplied DRM-free through Kobo.</p>
<p>About the only significant thing missing is details of how to verify RFC 9421 HTTP Signatures. That's understandable as they're pretty new, but a bit annoying as that's what a lot of servers are sending now. Similarly, there's a good write up of how to publish a poll, but not much about voting or publishing the results.</p>
<p>The "Far Horizons" chapter is particularly exciting - giving a speculative overview of what AP <em>could</em> be used for. I, for one, am particularly looking forward to putting my Internet Connected Fridge on social media 😆</p>
<p>Ultimately ActivityPub is a living and evolving set of standards. No book can possibly keep up with all the changes happening to it - but Evan does a brilliant job of bringing together all the moving parts and creating a coherent picture of the standard.</p>
<p>Highly recommended if you're interested in understanding the fundamentals of the Fediverse!</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74414&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Review: Ruined Theatre's A Midsummer Night's Dream ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/" />
<id>https://shkspr.mobi/blog/?p=74461</id>
<updated>2026-08-31T09:51:55Z</updated>
<published>2026-08-31T11:34:08Z</published>
<category scheme="https://shkspr.mobi/blog" term="shakespeare" /><category scheme="https://shkspr.mobi/blog" term="Theatre Review" />
<summary type="html"><![CDATA[The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us? Ruined Theatre brings a brilliant cast of seasoned West End performers to strut…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/"><![CDATA[<p>The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us?</p>
<p>Ruined Theatre brings a brilliant cast of seasoned West End performers to strut their hour among the ruins of Abbey Wood. Hey, gentrification has its benefits, OK?</p>
<p><a href="https://www.instagram.com/ruined_theatre/"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/msnd.webp" alt="Poster for the show, an explosion of colour." width="1024" height="527" class="aligncenter"></a></p>
<p>I don't know how many times I've seen "Dream", but I know I've never seen it performed in an actual wood during summer. Booking the tickets a few weeks ago during England's heatwave, it sounded perfect. A warm, dusky evening, accompanied by færies and asses. The British weather, of course, had other ideas.</p>
<h2 id="the-show-must-go-on"><a href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#the-show-must-go-on">The Show <em>Must</em> Go On</a></h2>
<p>The storm clouds were, as the bard wrote, heavy, black and, pendulous. Outside it may be raining, their makeup may be flaking, but everyone knows that Shakespeare is best played when defying the elements, right?</p>
<p>Even in the rain, it was great! Theseus and Hippolyta as selfie-obsessed poseurs made for a delightful start. Recasting Athens as Lesnes was a great touch. And then we were led through the woods. Rather than traipse us from scene to scene, we settled in to a clearing - bringing our own camping chairs with us - and watched the magic unfold.</p>
<p>Half the fun is in watching children and teenagers giggling at Hermia's rage and Bottom's overconfident bombast. But you can't go wrong with actors studiously ignoring the downpour and professing their (misplaced) love for each other. Honestly, who'd lie down in the mud just to make us chuckle? How many laughs can you ring out of a man with an ass's head? Lord, what fools these mortals be!</p>
<p>It is a fairly straightforward production. Aside from modern dress there wasn't much updating of the text other than trimming it down. The smoke machine might have been an eerie touch on a still summer's night, billowing around us, instead the wind took it before it had a chance to settle. The incidental music worked well - especially the intertextuality of Pyramus & Thisbe playing to the Romeo+Juliet soundtrack - but the speakers were over-driven and distorted. A small crimp on an otherwise fine production.</p>
<h2 id="reflections-in-a-dappled-pond"><a href="https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#reflections-in-a-dappled-pond">Reflections in a dappled pond</a></h2>
<p>I'm fairly sure I once played Demetrius in a youth production. Or possibly Lysander. I know I got to kiss Helena. Or possibly Hermia. The mind plays funny tricks as you age. Some of the more dreary prose becomes light and airy. The laughs which felt forced come more easily. The gender politics a little more nuanced.</p>
<p>You can never go back, of course. But you will always remember your first stage kiss with Hermia (or possibly Helena) with great affection. Seeing Shakespeare again and again and again in a hundred different variations just helps you realise what a master storyteller he was.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74461&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[ActivityBot is the recipient of an NLnet grant!]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/" />
<id>https://shkspr.mobi/blog/?p=74406</id>
<updated>2026-08-30T10:32:47Z</updated>
<published>2026-08-30T11:34:55Z</published>
<category scheme="https://shkspr.mobi/blog" term="ActivityBot" /><category scheme="https://shkspr.mobi/blog" term="ActivityPub" /><category scheme="https://shkspr.mobi/blog" term="fediverse" /><category scheme="https://shkspr.mobi/blog" term="NLnet" />
<summary type="html"><![CDATA[Back in February, I applied for NLnet's Next Generation Zero grant. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it: Reclaim the public nature of the internet Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up. I run ActivityBot - it is a single-file ActivityPub server suitable for…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/"><![CDATA[<p>Back in February, I applied for <a href="https://nlnet.nl/NGI0/">NLnet's Next Generation Zero grant</a>. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it:</p>
<blockquote><p>Reclaim the public nature of the internet</p>
<p>Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up.</p></blockquote>
<p>I run <a href="https://gitlab.com/edent/activity-bot">ActivityBot</a> - it is a single-file ActivityPub server suitable for launching automated accounts and designed as a learning tool for those who want to understand how the protocol works. Several people have told me how useful it is, but I haven't had the time to make it better. So I decided to stick in a last-minute application to the fund.</p>
<p>I really didn't know how much to apply for - or even if my project would be suitable for funding - so I cheekily asked for €10,000. After a few months of back-and-forth, I'm delighted to announce that I was successful!</p>
<p>In the spirit of openness, this blog post details how the NLnet grant process worked for me and what I'll be using the money for.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp" alt="NLnet logo." width="900" height="200" class="aligncenter">
<h2 id="the-process"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#the-process">The Process</a></h2>
<p>The application was delightfully simple. Here's what it asked for, along with my answers. If you apply, please don't copy these verbatim; use your own words.</p>
<blockquote>
<ul>
<li>Abstract : A single file server for ActivityPub. Designed for write-only bots. Allows any project to quickly and easily start publishing automated content to the Fediverse. Uses PHP, no other dependencies.
</li><li>Experience : I am the sole developer of Single File ActivityPub - https://gitlab.com/edent/activitypub-single-php-file<br>I was formerly the UK Government's representative to the W3C and have contributed to various ActivityPub projects and specifications.
</li><li>Amount : € 10000
</li><li>Use : The fund will be used for development, testing, promotional activity (including conference travel).<br>I anticipate this will fund 6 months of development. I have funded all previous development.<br>
</li><li>Comparison : Most ActivityPub services are complex. They implement a full specification and are designed for multi-user environments. Other projects allow reading and writing. ActivityBot is deliberately designed to be as simple as possible. A single file to upload, one user, publish only.<br>This will enable more projects to be able to instantly start publishing with low development cost and close to zero hosting cost.
</li><li>Challenges : Formal spec verification and a security audit will be the main technical challenges. The ActivityBot software has been running well for over a year. The funding will allow for better compatibility and security.
</li><li>Ecosystem : The project has mostly targeted individuals who want to run small bots. After further development, the project will engage with IoT providers, smaller publishers, open source projects who wish to publish updates, and other relevant parties.
</li></ul>
</blockquote>
<p>I was told there was intense competition. After a couple of months, I received word that I'd made it to the 2nd round.</p>
<p>What then followed was a <em>very</em> polite interrogation about my ideas, how I would develop the project, what I would use the money for, and what my AI usage policy was. They also wanted a breakdown of the main tasks - with the understanding that this would be a provisional document subject to change.</p>
<p>I was on <a href="https://shkspr.mobi/blog/2026/07/another-ridiculous-interrail-holiday-6379km-and-13-countries-over-7-weeks/">a train through Europe</a> when I wrote this. I don't claim it to be a brilliant document - but it got the job done!</p>
<blockquote><p>1. User Research
</p><p>Recruit 2 - 5 potential users. Offer an incentive (approx £20ea) to participate in a user research session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.
</p><p>Total effort 3 - 4 weeks.
</p><p>2. Standards Research
</p><p>Participate in ActivityPub user communities and standardisation groups. Attend virtual conferences (or any local to the UK). Approx 1 day per week for 6 months.
</p><p>3. Test Driven Development
</p><p>Create modern test harness, write test suite, iterate design based on tests. Anticipated effort 2 days per week for approx 3 months.
</p><p>4. Security Testing
</p><p>Work with the community and security professionals to test the resultant code. This will use human testers and normal fuzzers - this will not use AI tools. Anticipated effort 2 days per week for approx 2 months.
</p><p>5. User Acceptance Testing
</p><p>Recruit 2 - 5 potential users (ideally different to the research participants). Offer an incentive (approx £20ea) to participate in a user acceptance session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.
</p><p>Total effort 3 - 4 weeks.
</p><p>6. Updates Based on Research, Testing, and Security
</p><p>While it would be lovely to anticipate getting everything right first time, the reality is that changes will need to be made based on the findings of the above. This will take up the remainder of the allocated time.</p></blockquote>
<p>Again, there was a little more back and forth. But a few weeks later I was informed that I was at the final stage, pending review. And, a few weeks after that, I was told my project had been given the green light.</p>
<p>I was invited to a group call where the very friendly team discussed the practicalities of the grant, what it could and couldn't fund. I also met a bunch of other people who'd also won.</p>
<p>The final stage was writing a proper Memorandum of Understanding. With the help of one of the team (thanks Victoria!) I was able to turn my scrappy plan into something a bit more formal. The project tool NLnet uses made it easy to build up a plan and put € amounts by each task.</p>
<p>The idea is that I will invoice against the grant whenever I have completed a task or sub-task. Obviously I don't want to leave invoicing until the end of the project, but I also need to be mindful of the foreign exchange fees charged by my bank for receiving Euro payments.</p>
<h2 id="final-project-plan"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-project-plan">Final Project Plan</a></h2>
<p>This is the plan I submitted. It represents what I hope to accomplish and how I'll draw down on the grant. I suspect this will change as the months go on.</p>
<hr>
<p>ActivityBot is an Open Source project which aims to develop, maintain, and improve a minimum viable ActivityPub server in a single PHP file.</p>
<p>The project is run by Terence Eden (trading as @edent); a developer residing in England.</p>
<p>This project is expected to run for approximately 6 months. All of the deliverables will be openly licenced using either an OSI approved software licence or a Creative Commons licence.</p>
<p>The high-level aims of the project are for ActivityBot to be:</p>
<ol>
<li><p>A fully compliant ActivityPub server, running in a single PHP file.</p></li>
<li><p>A teaching tool to help developers understand the practical aspects of creating an ActivityPub server.</p></li>
<li><p>A practical method of publishing automated messages to the Fediverse.</p></li>
<li><p>A promotional tool to show how simple and easy ActivityPub development can be.</p></li>
<li><p>A secure and usable tool written in modern PHP.</p></li>
<li><p>Written by humans, with no AI/LLM generated code.</p></li>
</ol>
<p>In light of NLnet's non-profit status, costs assume a discounted rate of €330 per day (£280). Incidentals such as hardware, software, travel, or sundries will be charged at cost with receipts provided.</p>
<h2 id="prepare-for-initial-release"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#prepare-for-initial-release">Prepare for initial release</a></h2>
<p>Ensure that the project is in a suitable state for initial release and future development.</p>
<p>Deliverable: Updates published to GitLab.</p>
<ul>
<li><p>€495 Prepare initial release. Clarify licencing, solicit community engagement, include example usage.</p></li>
<li><p>€495 Standards Research. Collation of standards websites. Ensure code comments refer to specific standards. Publish blog post(s) about findings for others to reference.</p></li>
</ul>
<h2 id="user-research"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-research">User Research</a></h2>
<p>Recruit up to 10 participants for a user-research study. Participants should represent the diversity of the Fediverse.</p>
<p>Investigate what participants want from a tool like ActivityPub. The project plan may be adapted following the results of this study.</p>
<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on the results will be pushed to GitLab.</p>
<ul>
<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>
<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>
</ul>
<h2 id="test-driven-development"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#test-driven-development">Test Driven Development</a></h2>
<p>Create a modern test harness, write test suite, iterate design based on tests.</p>
<p>Deliverable: Tests published to GitLab. Blog posts published about the process and results.</p>
<ul>
<li><p>€330 Set up test suite</p></li>
<li><p>€330 Write tests</p></li>
<li><p>€330 Fixes based on test results</p></li>
</ul>
<h2 id="security-testing"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#security-testing">Security Testing</a></h2>
<p>Working with NLnet's security offering, ensure that the project meets modern security requirements.</p>
<ul>
<li>€720 Work with security team to assess security risks and possible mitigations. Fixes based on security team feedback</li>
</ul>
<p>Deliverable: Updates published to GitLab. Blogs published about the process and results.</p>
<h2 id="user-acceptance-testing"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-acceptance-testing">User Acceptance Testing</a></h2>
<p>Recruit up to 10 participants for a user-acceptance study. Participants should represent the diversity of the Fediverse.</p>
<p>Investigate whether participants are able to use ActivityBot. See which aspects need improvement. The project plan may be adapted following the results of this study.</p>
<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on feedback will be published to GitLab.</p>
<ul>
<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>
<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>
</ul>
<h2 id="conferences-and-standards-work"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#conferences-and-standards-work">Conferences and Standards Work</a></h2>
<p>Open Source participation often depends on attending conferences, either in person or virtually. Getting involved in the standardisation process ensures that future versions of ActivityPub and associated standards will be suitable for the community.</p>
<p>Deliverables: Presentations material (slideware), speaking at conferences (may be published as video), conference outputs. Where possible, these will be available under a suitable Creative Commons licence.</p>
<ul>
<li><p>€700 Travel and accommodation to one EU conference</p></li>
<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>
<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>
</ul>
<h2 id="final-release"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-release">Final release</a></h2>
<p>Creating a final release for this phase of the ActivityBot project. This will involve incorporating all feedback received so far, improving documentation, and publishing code.</p>
<p>Deliverable: Updates published to GitLab. Blog post written. Release announcements.</p>
<ul>
<li><p>€330 Phase 1: Process and implement feedback from users</p></li>
<li><p>€330 Phase 2: Bug fixes</p></li>
<li><p>€330 Phase 3: Features</p></li>
<li><p>€330 Phase 4: Bug fixes</p></li>
<li><p>€330 Phase 5: Features</p></li>
<li><p>€330 Phase 6: Remedial work</p></li>
<li><p>€330 Process and implement feedback from accessibility scan</p></li>
<li><p>€330 Final release</p></li>
</ul>
<h2 id="next-steps"><a href="https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#next-steps">Next Steps</a></h2>
<p>I've already begun work on updating the code. If you'd like to get involved, or have suggestions or bug reports - please <a href="https://gitlab.com/edent/activity-bot">take a look at ActivityBot on GitLab</a>.</p>
<p>I'll be putting out a call for user-research participants once I've had a chance to catch my breath 😆</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74406&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[A simple "copy this code" button in JavaScript]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/" />
<id>https://shkspr.mobi/blog/?p=69787</id>
<updated>2026-08-30T18:29:45Z</updated>
<published>2026-08-29T11:34:49Z</published>
<category scheme="https://shkspr.mobi/blog" term="HowTo" /><category scheme="https://shkspr.mobi/blog" term="HTML" /><category scheme="https://shkspr.mobi/blog" term="javascript" />
<summary type="html"><![CDATA[Next to all the code samples on this blog is a little "copy" button. That makes it easier to grab any of the code I've shared. The HTML and JS is delightfully simple: <button onclick="navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );" title="Copy code" >⧉</button> The navigator.clipboard.writeText needs a user interaction to w…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/"><![CDATA[<p>Next to all the code samples on this blog is a little "copy" button. That makes it easier to grab any of the code I've shared.</p>
<p>The HTML and JS is delightfully simple:</p>
<pre><code class="language-html"><button
onclick="navigator.clipboard.writeText(
this.parentNode.getElementsByTagName('code')[0].textContent
);"
title="Copy code"
>⧉</button>
</code></pre>
<p>The <code>navigator.clipboard.writeText</code> needs a user interaction to work - so it is tied to a click on the button.</p>
<p>It takes some plaintext content. But how to get that content? My code samples look like this:</p>
<pre><code class="language-html"><pre itemscope itemtype=https://schema.org/SoftwareSourceCode translate=no>
<button onclick="navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );">⧉</button>
<span>
<img alt height=32 src=html.svg width=32>
<span itemprop=programmingLanguage> HTML</span>
</span>
<code itemprop=text>[…]</code>
</pre>
</code></pre>
<p>There are various ways I could get that <code><code></code> element:</p>
<ul>
<li>Give it a unique ID (but that might clutter the code, or conflict with something else).</li>
<li>Use <code>this.nextSibling.nextSibling</code> (but that might not work if the layout changes).</li>
<li>Use <code>this.lastChild.textContent</code> (but, again, depends on the layout staying the same).</li>
<li>Select based on <code>itemprop</code> (could make the code a bit longer).</li>
<li>Complex filtering on a NodeList (urgh).</li>
</ul>
<p>None of those are particularly bad <i lang="la">per se</i>, so I've chosen the method which makes most sense to me.</p>
<p>You can read more about my <a href="https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/">Classless Design</a>, and how I use <a href="https://shkspr.mobi/blog/2024/08/what-programming-language-is-in-this-code-block/">metadata to identify programming languages</a>, including whether <a href="https://shkspr.mobi/blog/2026/01/should-htmls-blocks-be-translated/">HTML's code blocks be translated</a>.</p>
<p>To let people know that it has worked, I've added a little <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/popover">popover</a>.</p>
<p>Every piece of code has it's own <code>dialog</code> element with a unique id:</p>
<pre><code class="language-html"><dialog
id=pop
popover=hint>Copied JS to 📋</dialog>
</code></pre>
<p>No JavaScript is required to show the popover when the copy button is pressed:</p>
<pre><code class="language-html"><button popovertarget=pop popovertargetaction=show>
</code></pre>
<p>Closing the the popover hint doesn't require JS; clicking outside it will dismiss it. But a little scrap of JS on the button's <code>onclick</code> will make it disappear after a few seconds:</p>
<pre><code class="language-js">setTimeout(
function() {
document.getElementById("pop").hidePopover();
},
3000);
</code></pre>
<p>The browser's default is to place it in the middle of the screen.</p>
<p>Positioning the popup so it is in proximity to the button also requires CSS - no JS.</p>
<pre><code class="language-css">dialog[popover] {
inset: unset;
position: absolute;
position-area: top;
padding: .5em;
}
</code></pre>
<p>OK, that started out simple but got a bit more complex. Sorry!</p>
<p><ins datetime="2026-08-30T18:28:40+00:00">Update!</ins> It turns out there are some accessibility issues with this approach. See <a href="https://codepen.io/editor/ccwilcox/pen/01a04d8d-3691-7003-b8f6-df7439ecbd0a">these updates by Curtis Wilcox</a>.</p>
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<thr:total>2</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA["iT woRKs BeTter in THe aPp!!"]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/" />
<id>https://shkspr.mobi/blog/?p=73004</id>
<updated>2026-08-25T07:14:14Z</updated>
<published>2026-08-28T11:34:46Z</published>
<category scheme="https://shkspr.mobi/blog" term="android" /><category scheme="https://shkspr.mobi/blog" term="Apps" /><category scheme="https://shkspr.mobi/blog" term="google" /><category scheme="https://shkspr.mobi/blog" term="rant" />
<summary type="html"><![CDATA[The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation. I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/"><![CDATA[<p>The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation.</p>
<p>I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar app. Is it possible to click on a calendar link and add it to my phone?</p>
<p>No.</p>
<p>Here's what <a href="https://support.google.com/calendar/answer/37100">Google has to say about the matter</a>:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/Google-Calendar-Help.webp" alt="To subscribe to a new calendar, you must use a computer web browser. You can't subscribe to a calendar in the Google Calendar app for Android, iPhone, or iPad." width="920" height="760" class="alignnone size-full wp-image-73005">
<p>Really?!? I mean, fucking <em>really</em>????</p>
<p>This isn't the most complex software engineering task known to humanity. Add a + button. Pop open a text entry field. Validate. Save. Done. I'm sure even the shitty Gemini model can vibe code that in a couple of months, right?</p>
<p>Anyway, I opened calendar.google.com on my phone (using desktop mode), added the calendar, and it magically appeared in the app.</p>
<p>This is just pathetic.</p>
<p>In fairness, this isn't only a Google problem. Many companies want a permanent presence on your homescreen and think you're too thick to use your browser's bookmarks feature. Maybe they're right. Maybe an app <em>is</em> the only way to increase the engagement KPI sufficiently so Quinn in the leadership squad can hit their OKRs and get a bonus.</p>
<p>So they build an app. Or, rather, they half-arse it. I've lost count of the number of times I've been told "it's easier if you use our app" only to be unceremoniously punted back to the web when I try to do anything outside of the app's narrow strictures.</p>
<p>I was there in the early days of phone apps. I built stuff for Symbian, BlackBerry, even the bloody Palm Pilot! The central problem with apps has always been that they are hard to update. Every new bit of functionality - or even a new page - needs to be tested on a thousand devices. Once done, it takes an age to distribute to users. The only way to solve that is to have the app dynamically pull in new functionality from a remote resource.</p>
<p>At which point, you've reinvented the Web browser!</p>
<p>Sure, there are some things you can <em>only</em> do with an app (<a href="https://developer.chrome.com/blog/serial-over-bluetooth/">although browsers are catching up</a>), and having an icon on the homescreen is useful (which is <a href="https://favicon.io/tutorials/favicon-sizes/">easy for sites to add</a>), as is offline functionality (which, again, <a href="https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers">is possible on the web</a>).</p>
<p>Oh.</p>
<p>If you want an app, fine. Do it. Just finish the job please!</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73004&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>10</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: The Infinite Sadness of Small Appliances by Glenn Dixon ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/" />
<id>https://shkspr.mobi/blog/?p=73408</id>
<updated>2026-07-23T22:11:55Z</updated>
<published>2026-08-27T11:34:48Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review" /><category scheme="https://shkspr.mobi/blog" term="Sci Fi" />
<summary type="html"><![CDATA[This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death? It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/Infinite-Sadness-of-Small-Appliances-1-532x815-1.jpg" alt="Book cover." width="200" class="alignleft size-full wp-image-73409">
<p>This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death?</p>
<p>It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a transfem robo-hacker in domestic peril, why clocks are so bossy, and whether art is a cure for grief.</p>
<p>The world-building is a little basic (The Algorithm™ is managing humanity's decline) but the characters are well constructed. A little derivative, it's true. Nevertheless, it is a touching tale, told well, and with a decent pace.</p>
<img src="https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73408&HTTP_REFERER=Atom" alt width="1" height="1" loading="eager">]]></content>
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<thr:total>1</thr:total>
</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Gadget Review: Thermal Master P3 Macro Lens ★★★★⯪]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/" />
<id>https://shkspr.mobi/blog/?p=74230</id>
<updated>2026-08-25T12:37:17Z</updated>
<published>2026-08-26T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="gadget" /><category scheme="https://shkspr.mobi/blog" term="infrared" /><category scheme="https://shkspr.mobi/blog" term="review" /><category scheme="https://shkspr.mobi/blog" term="thermal" /><category scheme="https://shkspr.mobi/blog" term="usb-c" />
<summary type="html"><![CDATA[The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried. Whereas previous cameras are good for bird watching, or wildlife spotting, or finding leaks at home - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics. Yup! See just how hot your CPU is getting…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/"><![CDATA[<p>The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3-thermal-camera-close-up.webp" alt="A small black camera with gold accents. It is held in the fingertips." width="3212" height="2409" class="aligncenter">
<p>Whereas previous cameras are good for <a href="https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/">bird watching</a>, or <a href="https://shkspr.mobi/blog/2026/08/gadget-review-t2-max-plug-in-thermal-camera/">wildlife spotting</a>, or <a href="https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/">finding leaks at home</a> - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics.</p>
<p>Yup! See just how hot your CPU is getting 🥵</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/pi.webp" alt="A thermal image of a raspberry pi. The CPU is in red while the rest of the board is green." width="1344" height="1008" class="aligncenter">
<p>Let's take it for a spin!</p>
<h2 id="unboxing"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#unboxing">Unboxing</a></h2>
<p>As well as the camera (which looks <em>gorgeous</em> with its gold trim) you get a carry-case, USB-C extension cable, and a Lightning converter for older iPhones.</p>
<p>The metal casing of the camera feels delightful and gives it a bit of heft. The focus wheel is reasonably stiff which makes it easier to position just right.</p>
<h2 id="sample-photos"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#sample-photos">Sample Photos</a></h2>
<p>These are the raw images taken directly from the app. I haven't resized or altered them in any way. What you see is what you get. Here's a hot-spot on a circuit board:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/hotspot.webp" alt="A circuit rendered in grey with a bright red line on it." width="1344" height="1008" class="aligncenter">
<p>The natural size of the images is 1344x1008. That's obviously upscaled from the sensor, but there's a surprisingly amount of detail in there.</p>
<p>Here's a small circuit board which has just booted up:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Circuit-long-shot.webp" alt="A small circuit. Two of the chips are noticeably hotter than the rest of the board." width="1344" height="1008" class="aligncenter">
<p>Where the P3 shines is when you twist the manual lens all the way down to macro. You can get about 2cm away from a surface and stay in focus.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Chip-close-up.webp" alt="Close up of a small chip. It is hot, the traces are visible in the background." width="1344" height="1008" class="aligncenter">
<p>Obviously don't get that close to something red hot!</p>
<p>Annoyingly, the images are uncompressed JPEG and weigh in around 6MB each. I've losslessly compressed these to WebP, which is about 10% of the size.</p>
<h3 id="colours"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#colours">Colours</a></h3>
<p>There are a variety of different colour palettes to play with. Some are more useful than others. Here's a mug of hot and delicious matcha rendered in the various colours:</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Hot-Tea-Montage.webp" alt="Four photos of a mug. The colours show how hot the tea is." width="2688" height="2016" class="alignleft">
<p>Scrolling through the colours is a little difficult in the app (more on that later) but once you've found one you like, it stays that way for the photography session.</p>
<h3 id="exif"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#exif">EXIF</a></h3>
<p>Geolocation is taken from the phone - there's no GPS chip in the camera. You can refuse location permission to the app and it will work just fine.</p>
<p>That's just about all you get other than the time and the model name of <code>USB_IR_RS300_P2L</code> - the infrared details aren't recorded separately.</p>
<h2 id="video"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#video">Video</a></h2>
<p>The video doesn't upsample the image, it has a resolution of 504x672 playing at 25fps. Audio is recorded from the phone's microphone and is 64kbps mono. A minute of video is around 22MB. I've recompressed this one for the web.</p>
<p></p><div style="width: 620px;" class="wp-video"><video class="wp-video-shortcode" id="video-74230-2" width="620" height="465" preload="metadata" controls="controls"><source type="video/mp4" src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4?_=2"><a href="https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4">https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4</a></video></div><p></p>
<h2 id="the-app"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#the-app">The App</a></h2>
<p>It is, sadly, an inevitability that good hardware is always accompanied by a substandard app. The <a href="https://play.google.com/store/apps/details?id=com.thermalmaster.p2telephoto">Thermal Master Android App</a> is the only way to access the camera. It has a relatively easy to use interface with plenty of options.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/Camera-interface.webp" alt="Camera interface with janky UI." width="504" class="aligncenter">
<p>As you can see from the word "brightness" the UI is a little janky in places.</p>
<p>There's a decent amount of settings to fiddle with.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/more-settings.webp" alt="Settings screens with various temperature settings." width="504" class="aligncenter">
<p>You can also change which elements get displayed on the final image.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/settings.webp" alt="Settings to control the camera." width="504" class="aligncenter">
<p>Unfortunately, it is also a bit crash-happy. Most times I used it, the app would randomly close. It takes a little while to re-open thanks to a mandatory animation. So it gets a bit annoying. Flicking through some of the options can be slow and tedious. It also doesn't respect the phone's orientation, so images may be 90⁰ off what you expect.</p>
<p>The app updated the firmware on the camera, but didn't say what had changed.</p>
<p>It takes photos and videos, allows you to share them, and has a bunch of options to play with - but it does have a habit of crashing just when you're about to take the perfect shot. There is also zoom available, but it is digital only - so you're just making the pixels bigger rather than getting optically closer to the object you're scanning.</p>
<h2 id="linux-info"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#linux-info">Linux Info</a></h2>
<p>I tried plugging it in to a Linux laptop. It shows up as <code>3474:45a2 Thermal Master Technology Co., Ltd. P3</code> - but that's about it. There's no way I can find to access the thermal images.</p>
<p>To be fair, this is explicitly sold as an Android and iOS device. I'm hopeful someone will be able to reverse engineer it.</p>
<h2 id="cost-and-final-thoughts"><a href="https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#cost-and-final-thoughts">Cost and Final Thoughts</a></h2>
<p>Thermal cameras are expensive. This will run you about <a href="https://link.amazon/B0aFBVuY9">£280 on Amazon</a> or about <a href="https://thermalmaster.com/en-gb/products/p3-thermal-camera-for-iphone-and-android">£260 direct</a>. Readers of this blog can get 10% off using code <code>THERMALBF10</code></p>
<p>If you run a hackspace, this is a no-brainer. The ability to see hot-spots on your circuits is immediately useful. The detail is impressive, allowing you to see exactly what's causing problems.</p>
<p>If you're a hobbyist, this is definitely in the "ask Santa if you've been good" category. You'll find it handy on any small projects you have, or to diagnose faults with electrical equipment.</p>
<p>For non-macro uses, it's also pretty good. You might be better off with a dedicated device if you want to go <a href="https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/">hunting wildlife</a> or doing <a href="https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/">home surveys</a>.</p>
<p>The only fly in the ointment is the app. While somewhat customisable, it does repeatedly crash and it isn't the easiest to use or set up. I found that pretty frustrating and have fed back the problem to the developers. I appreciate it saving high quality images - but a PNG or lossless WebP would be easier to work with than massive JPGs.</p>
<p>Ultimately, this is an excellent thermal camera. It looks lush, it is customisable, the images are high quality, and the macro-lens is surprisingly useful.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Theatre Review: Cats at Regent's Park Open Air Theatre ★★★★☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/theatre-review-cats-at-regents-park-open-air-theatre/" />
<id>https://shkspr.mobi/blog/?p=74380</id>
<updated>2026-09-01T22:02:57Z</updated>
<published>2026-08-25T11:34:22Z</published>
<category scheme="https://shkspr.mobi/blog" term="musical" /><category scheme="https://shkspr.mobi/blog" term="Theatre Review" />
<summary type="html"><![CDATA[Cats is so silly! In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature. Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/theatre-review-cats-at-regents-park-open-air-theatre/"><![CDATA[<p>Cats is so <em>silly!</em></p>
<p>In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature.</p>
<p>Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in service of better understanding the mysteries of our moggies.</p>
<p>Does there need to be so many sequins? So much dry ice? Such a quantity of pyrotechnics?</p>
<p>No, probably not. But it all adds up to a spectacular which will keep you grinning.</p>
<p>The deficiencies in Cats are somewhat inherent. The scrapbook story doesn't make a lick of sense. It is more like a variety show than musical theatre. The lyrics are, at times, utterly asinine. The music soars, until someone starts playing what sounds like a genuine 1980s Casio keyboard - and all you can hear is squelch.</p>
<p>But then Gary Wilmot (!!!) comes on as Gus and all is forgiven on a haze of metatextual glory.</p>
<p>The choreography and dancing are exemplary. The singing occasionally gets muddled but is mostly delightful. The stage is perfect - the wind blowing through the trees and the moon gently rising only helps to accentuate the atmosphere.</p>
<p>The pre-show is good. As well as a variety of food stalls, patrons are encouraged to bring their own food and drink for a picnic. There are plenty of tables and a couple of selfie points.</p>
<p>The programme isn’t horrendous at £6 but still feels like it contains more advertising than content. The queues for the loos were outrageously long and the stalls weren't particularly clean.</p>
<p>There's nothing to do post-show except trudge back through the park. The selfie point is still illuminated if you want to queue for that. Even the t-shirt sales stopped after the interval.</p>
<p>I first saw Cats in the West End some time in the 1980s as a child and loved it. Afterwards my parents asked if I wanted to see a ballet or an opera next. "Eurgh! No! <em>Boring!</em>" I said. They politely informed me that I'd just seen both in one show and my juvenile mind was blown.</p>
<p>A few decades later I saw Cats on Broadway - shortly before it closed, I think. The C90 cassette they used to play the music was warbling like a demented bird and the sets looked equally tired. Despite the half empty auditorium, the cast attacked the songs with vigour. I still loved it.</p>
<p>And, today, I still had goosebumps. Maybe it was the unseasonable chill in the air, maybe it was the moonlight, or maybe it was the magic of Cats!</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Why do audience members choose specific shows at the Edinburgh Fringe?]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/" />
<id>https://shkspr.mobi/blog/?p=74330</id>
<updated>2026-09-01T22:05:06Z</updated>
<published>2026-08-24T11:34:45Z</published>
<category scheme="https://shkspr.mobi/blog" term="data" /><category scheme="https://shkspr.mobi/blog" term="EdFringe" />
<summary type="html"><![CDATA[On our recent trip to the Edinburgh Fringe, I was bemused by just how little effort performers put in to finding out why people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with some performers paying tens of thousands of pounds. The way performers recoup the costs of performing is by getting people to pay to see a show. Acts are spending huge amounts…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/"><![CDATA[<p>On our <a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/">recent trip to the Edinburgh Fringe</a>, I was bemused by just how little effort performers put in to finding out <em>why</em> people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with <a href="https://www.scotsman.com/business/edinburgh-festival-fringe-2025-the-true-cost-of-performing-at-the-worlds-largest-arts-event-laid-bare-5247134">some performers paying tens of thousands of pounds</a>. The way performers recoup the costs of performing is by getting people to pay to see a show.</p>
<p>Acts are spending huge amounts on flyers, posters, and other promotional activities. But is any of it worthwhile?</p>
<p>The performer Danielle Solof has a fascinating blog post "<a href="https://daniellesolof.substack.com/p/my-real-fringe-budgets-line-by-line">My Real Fringe Budgets, Line-by-Line</a>" which details the actual costs of her taking two solo shows to the Fringe. She meticulously details the price of everything from transport and food, to advertising and graphic design. She says:</p>
<blockquote><p>I paid for outdoor ads because absolutely no one in Edinburgh knew who I was. They <em>did</em> help, but you still have to grind to get an audience in.</p></blockquote>
<p>My question to her - and all performers - is how do you know what drives an audience member to see your show?</p>
<p>It can't have escaped your attention that everything we do online is tracked. If you buy so much as a toothpick, the retailer knows which YouTube reviews you watched, which words you searched for, the other products you considered, and the specific adverts you clicked on.</p>
<p>In Edinburgh, no one knows nothing.</p>
<p>At the end of nearly every show the performer begged us to leave a review on the Fringe website and to tell our friends. In absolutely <em>none</em> of the shows did the performer ask why we were there, how we found out about the show, which poster or leaflet attracted us, or whether we followed them on social media.</p>
<p>All that money spent on posters and no one knows if they work. As the old saying goes "<a href="https://quoteinvestigator.com/2022/04/11/advertising/">Half the money I spend on advertising is wasted, and the trouble is I don’t know which half.</a>".</p>
<p>So, in an attempt to bring a <em>little</em> data to proceedings, here are how we chose the 26 shows we saw. I don't claim this is representative of everyone, but I think it might be illustrative. In rough order of importance were:</p>
<h2 id="proximity"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#proximity">Proximity</a></h2>
<p>The EdFringe app has a "nearby now" feature. Click on it and you get a list of shows starting soon which are only staggering distance away.</p>
<p>I cannot stress enough how much of a motivator that was. When you've spent all day traipsing, the last thing you want to do is <em>another</em> 20 minute walk uphill to see a provocative new piece of challenging theatre told through finger puppets.</p>
<p>About 20% of the shows we saw were via that feature.</p>
<p>Roughly another 40% were because the show was close to something else we really wanted to see. We knew that we wanted to see show X, so we looked for shows which weren't too far away from that venue. Yes, Edinburgh is a compact city with decent public transport, but it is much easier to walk round the corner or stay to have a drink in the venue's bar.</p>
<p>You can <em>really</em> want to see a show, but if it is a 20 minute walk between venues and it starts 15 minutes after your last show ends, you'll skip it. I'd say that location was the key driver in most of our choices.</p>
<p>I guess my top tip to any performer would be to be as near as physically possible to a bigger act!</p>
<h2 id="friends"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#friends">Friends</a></h2>
<p>A quarter of the shows we went to were because either a friend-of-a-friend was performing, or a friend booked tickets and asked if we wanted to tag along.</p>
<p>You are morally obliged to go to your friends' shows. Similarly, if a mate says "Oh, my friend has a show on this year", you have to make the effort to go.</p>
<p>Perhaps it is a bit blasé to say that word-of-mouth works, but it's a cliché becausé it is trué.</p>
<h2 id="flyers-and-leaflets"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#flyers-and-leaflets">Flyers and Leaflets</a></h2>
<p>We collected approximately 5,374 different promotional leaflets during our week there. Most of the time we were handed a leaflet by someone paid to hand out leaflets. They were either wordlessly stuffed into our hands, or delivered with a monotone "wanna see improv comdy?" Bleh.</p>
<p>A few actually spoke to us about the show when we asked questions, which was a deciding factor in seeing a couple of performances.</p>
<p>The best flyerers were, undoubtedly, the performers themselves. Kat Ronson in her <a href="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-kat-ronson-millennial-girl/">Millennial Girl</a> guise drawled at us "You look thin and pretty. You're allowed to come to my show." Instant sale!</p>
<p>Similarly, one rather famous comedian walked up to us and said "You look like theatre people!" and proceeded to pitch their show - which was a delightful encounter and would have sold us a ticket if we weren't leaving that day.</p>
<p>Some flyers had a QR code or URl on them so we could watch a trailer of the show. We didn't watch any of them. Perhaps we should have?</p>
<h2 id="posters"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#posters">Posters</a></h2>
<p>Surprisingly effective at drawing the eye! The ones which were just a photo of the comedian looking a bit "whacky" were dull. The ones of performers in their most seductive poses were a little naff. The ones which were just a close up of someone's face only really work if that person is incredibly famous, otherwise you're just left thinking "who?"</p>
<p>But a few posters made us stop and immediately search for the show. Graphic design is a professional skill and one worth investing in.</p>
<p>Some posters were everywhere. I took an instant (and uncharitable) dislike to one poster featuring a smug-looking twat and I swear he followed me around town. Some posters only appeared near the performance venue.</p>
<p>Incidentally, there were a couple of posters which had clearly just been fed into an AI generator. Lazy and off-putting.</p>
<h2 id="reviews"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#reviews">Reviews</a></h2>
<p>The Fringe doesn't allow weighted star reviews - so you can't immediately see if the consensus is that the show is a hit or a miss. Several of the shows we didn't enjoy got excellent reviews (from morons) and some of the shows we loved were panned (presumably by the same morons).</p>
<p>In truth, I don't think the reviews influenced our decision to see anything.</p>
<h2 id="what-stopped-us-going-to-shows"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#what-stopped-us-going-to-shows">What <em>Stopped</em> Us Going To Shows</a></h2>
<p>For every action there is an equal and opposite reaction. I think it is important for performers to know what stopped someone clicking the "buy" button for their show.</p>
<h3 id="ticket-cost-value-for-money"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#ticket-cost-value-for-money">Ticket Cost / Value For Money</a></h3>
<p>Mondays and Tuesdays saw lots of shows doing a 2-for-1 promotion. I didn't mind spending £30 for two of us to take a risk on something. Come Wednesday, I wasn't prepared to pay £60 for a 45 minute show.</p>
<p>I know "surge pricing" gets a bad rap, but <a href="https://shkspr.mobi/blog/2024/09/why-does-no-one-discuss-negative-dynamic-pricing/">dynamic pricing of underselling shows</a> might help. If you've only sold four seats for today, perhaps drop the price? I don't know if the Fringe software supports that - but it seems obvious to me that having 10 people paying a fiver is better than four people paying a tenner.</p>
<h3 id="crap-signal-long-queues"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#crap-signal-long-queues">Crap Signal / Long Queues</a></h3>
<p>We tried to get in to a circus show. My phone didn't have enough signal for the app to work and the nearest box office had a massive queue. So we bailed.</p>
<p>If the venue had WiFi (not a given, weirdly) it would have gotten them an extra sale. If the ticket staff could take contactless (lots of performers did) we'd have happily paid.</p>
<p>You have to make it easy for people to give you money.</p>
<h3 id="not-enough-time"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#not-enough-time">Not Enough Time</a></h3>
<p>This is completely out of the performers' control. We had 6 days and saw about 4 shows per day. We could have seen more, but we needed to eat, explore, and sleep.</p>
<p>Speaking of which, there were several midnight performances which looked excellent - but I also needed to get up the next day to see more shows. Sleep won!</p>
<h3 id="too-famous"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#too-famous">Too Famous</a></h3>
<p>I'd love to see that guy who's on the telly. But I can watch him on the telly. That show looks like a massive success, so I'm sure it'll tour round London soon.</p>
<h3 id="sell-outs"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#sell-outs">Sell Outs</a></h3>
<p>A few shows sold out before we could get tickets. Good for them! If that was your show, you probably don't need this blog post.</p>
<h2 id="better-art-through-commerce"><a href="https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#better-art-through-commerce">Better Art Through Commerce</a></h2>
<p>Art should be driven by passion.</p>
<p>But every performer I know listens back to their shows to see what works and what didn't. If a joke falls flat, it's cut. If a riff gets a big laugh, it's incorporated. That's the essence of data driven decision making.</p>
<p>I wish every performer at the Fringe had a sell out audience and were able to recoup their costs. But that is never going to happen unless they spend time understanding what gets bums on seats.</p>
<p>So here are a few scattered thoughts on how they could do that.</p>
<ul>
<li>QR code at the end of the show leading to a survey. Literally ask people "what made you choose this performance?"</li>
<li>In the queue before the show, or as people are taking their seats, hand out a paper questionnaire.</li>
<li>Talk to the audience after the show. See if you can gain any insights about what made them attend.</li>
<li>As people are coming in, have a poster asking people to tick a box based on how they heard about the show.</li>
<li>Give each leaflet a unique code (or a code per person handing them out). Ask people to bring the leaflet with them so you can see which area/person/leaflet was most effective.</li>
<li>Each poster can have a unique QR code on it. Track whether the one by the station led to more ticket sales than the one in the underpass. Did the one in the gents toilets get <em>any</em> scans at all?</li>
</ul>
<p>Of course, all of the above rely on talking to people who made the choice to see you. This is classic <a href="https://en.wikipedia.org/wiki/Survivorship_bias">Survivorship Bias</a>. Sure, it'll help you work out what was <em>successful</em>, but you won't know why people looked at your show and chose something else. That said, it is <em>hard</em>. How do you find people who <i lang="la">ipso facto</i> aren't at your show?</p>
<ul>
<li>That could be as simple as asking people what they dislike about the leaflet when you hand it out.</li>
<li>Each poster or leaflet can have a unique QR code on it. Which ones cause people to scan, but then abandon the idea of buying a ticket?</li>
<li>Speak to people who came to the venue for a show other than yours. They obviously like the location, so non-confrontationally ask them why they didn't pick you?</li>
</ul>
<p>Some of these are easier than others. By themselves, they might give you a slightly misleading view of the data. But surely anything is better than looking at a half empty venue and wondering if those huge advertising costs did any good at all.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Death to px, long live ch!]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/death-to-px-long-live-ch/" />
<id>https://shkspr.mobi/blog/?p=63847</id>
<updated>2026-08-23T12:45:06Z</updated>
<published>2026-08-23T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="css" /><category scheme="https://shkspr.mobi/blog" term="design" /><category scheme="https://shkspr.mobi/blog" term="HTML" />
<summary type="html"><![CDATA[Pixels are a lie. Even if you think you're drawing something with "pixel perfect" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares. In CSS, pixels are a double lie: Note that 1px doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, 1cm in CSS often doesn't correspond to one hundredth of SI…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/death-to-px-long-live-ch/"><![CDATA[<p>Pixels are a lie. Even if you think you're drawing something with "<a href="https://shkspr.mobi/blog/2018/11/the-myth-of-the-pixel-perfect-grid/">pixel perfect</a>" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares.</p>
<p>In CSS, <a href="https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/Values_and_units#lengths">pixels are a double lie</a>:</p>
<blockquote><p>Note that <code>1px</code> doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, <code>1cm</code> in CSS often doesn't correspond to one hundredth of SI meter. On a large TV screen, it typically is longer than that. The lengths are perceptual: <code>16px</code> looks roughly the same on a phone, laptop, or TV screen at typical viewing distance.</p></blockquote>
<p>This blog is primarily text based. I want the <a href="https://journals.uc.edu/index.php/vl/article/view/5765/4629">width of the text to be readable</a> for the average human. So, rather than setting the main width to be a percentage of the screen, I set it based on character width using the <code>ch</code> unit - which <a href="https://meyerweb.com/eric/thoughts/2018/06/28/what-is-the-css-ch-unit/">isn't exactly a character</a> but good enough for my purposes:</p>
<pre><code class="language-css">--width-content: min(75ch, 100%);
main {
max-width: var(--width-content);
}
</code></pre>
<p>When it comes to padding and margins, the same is true. If I want a gap around an element, I want that gap to be in proportion to the text inside it.</p>
<p>For widths, it makes sense to re-use the <code>ch</code> unit. I want the gap to be in proportion to the text.</p>
<p>But for <em>height</em>, perhaps it doesn't make sense to express vertical distance on character width? In which case <a href="https://www.w3.org/Style/Examples/007/units.en.html">the <code>ex</code> unit can be used</a>. It is the size of a typical lower-case letter.</p>
<p>Just like my idea to <a href="https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/">eliminate CSS classes from my HTML</a>, it's possible to go too far with this. I haven't changed <em>every</em> reference from px to ch, I'm just experimenting to see if it works.</p>
<p>There's nothing wrong, immoral, or evil about using px - or any other measure unit. Using ch and ex fit with my particular proclivities.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: An Immense World - How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong ★★★☆☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-an-immense-world-how-animal-senses-reveal-the-hidden-realms-around-us-by-ed-yong/" />
<id>https://shkspr.mobi/blog/?p=72903</id>
<updated>2026-07-29T09:03:25Z</updated>
<published>2026-08-21T11:34:36Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Review" /><category scheme="https://shkspr.mobi/blog" term="science" />
<summary type="html"><![CDATA[This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision. This isn't a game of Top Trumps where all the animals are ranked by power.…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-an-immense-world-how-animal-senses-reveal-the-hidden-realms-around-us-by-ed-yong/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/07/9781473572737-jacket-large.webp" alt="Book cover featuring various animals." width="200" class="alignleft size-full wp-image-72904">
<p>This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision.</p>
<p>This isn't a game of Top Trumps where all the animals are ranked by power. Instead there's a gentle and passionate exploration of what these senses <em>might</em> mean to their owners. It is refreshingly candid about what we don't know, while always trying to convey a sense of wonder about the inherent <a href="https://en.wikipedia.org/wiki/Umwelt"><i lang="de">Umwelt</i></a> experienced by the animal.</p>
<p>But goodness me is it long. It seems that every time the editor told the author to cut out a paragraph, he stuck it in a footnote instead. The text is well referenced, but so are the footnotes, which means occasionally encountering sentences formatted like this:</p>
<blockquote><p>Despite several frustrating false leads, nobody’s ever found them.<sup>fn11,36,37,38,39</sup></p></blockquote>
<p>Speaking of which, the general formatting of the eBook is poor. The CSS contains all sorts of weird stuff which I needed to turn off, and is full of comments which probably should have been stripped before the book was distributed.</p>
<p>Science publishers still haven't grasped that eBooks don't need to relegate glossy images to the back of the book - they can go inline with the text!</p>
<p>This is a funny, heartfelt, and (perhaps overly) thorough book. It will gleefully send you down rabbit holes - even if you're ill-equipped to see in the dark and sense the bugs around you.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Asymmetric Agents]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/asymmetric-agents/" />
<id>https://shkspr.mobi/blog/?p=73594</id>
<updated>2026-08-20T06:17:00Z</updated>
<published>2026-08-19T11:34:52Z</published>
<category scheme="https://shkspr.mobi/blog" term="agentic" /><category scheme="https://shkspr.mobi/blog" term="AI" /><category scheme="https://shkspr.mobi/blog" term="future" />
<summary type="html"><![CDATA[One of the promises of the AI-filled future is that we'll all have highly capable autonomous servants "agents" to work for us. Even back in the 1990s, it was a common trope in future-gazing to insist that a person's personal slave agent would negotiate on their behalf. Ask your meek digital pal agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, …]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/asymmetric-agents/"><![CDATA[<p>One of the promises of the AI-filled future is that we'll all have highly capable autonomous <del>servants</del> "agents" to work for us.</p>
<p>Even <a href="https://shkspr.mobi/blog/2026/02/how-close-are-we-to-a-vision-for-2010/">back in the 1990s</a>, it was a common trope in future-gazing to insist that a person's personal <del>slave</del> agent would negotiate on their behalf. Ask your <del>meek digital pal</del> agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, and within your budget. The little <del>butler</del> agent scurries off and, without your intervention, finds the <em>perfect</em> place, negotiates with the restaurant's <del>house boy</del> agent and books you a slap up meal.</p>
<p>Marvellous! You can tell your <del>manservant</del> agent to buy you clothes, reserve a flight, do the grocery shopping, or buy your wife flowers without having to lift a finger.</p>
<p>But, of course, there's a fly in the ointment. Not all <del>valets</del> agents are created equally. You're sending your Raspberry Pi powered <del>peon</del> agent against the full might of Amazon's bazillion datacentres.</p>
<p>Can a low-complexity <del>serf</del> agent be bullied, outwitted, and manipulated by a more capable <del>henchman</del> agent? It seems obvious to me that the answer is yes. Humans have a set of cognitive biases which render us susceptible to advertising tricks. AI may have <a href="https://cacm.acm.org/research/rolling-in-the-deep-of-cognitive-and-ai-biases/"><em>different</em> biases</a> but will still be vulnerable to <a href="https://shkspr.mobi/blog/2017/03/how-to-hypnotise-an-artificial-intelligence/">hypnosis</a> and hacking.</p>
<p>Perhaps having my <del>secretary</del> agent negotiate with your <del>PA</del> agent to find a suitable meeting time for our Q2 KPI Deep Dive doesn't carry this sort of risk. But I'm sure that <del>scumbags</del> advertisers everywhere will be salivating at the thought of waylaying my innocent <del>footman</del> agent on its way to market.</p>
<p>A future where we delegate responsibility to <del>stochastic imbeciles</del> agents is one where we accept that we have no control over their susceptibility to more powerful and malevolent <del>thugs</del> agents.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[And then the men with guns tell you to do it anyway]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/and-then-the-men-with-guns-tell-you-to-do-it-anyway/" />
<id>https://shkspr.mobi/blog/?p=74161</id>
<updated>2026-08-17T11:31:25Z</updated>
<published>2026-08-17T11:34:24Z</published>
<category scheme="https://shkspr.mobi/blog" term="politics" /><category scheme="https://shkspr.mobi/blog" term="technology" />
<summary type="html"><![CDATA[In early February 2011 Egypt was in the middle of a political revolution. One morning, everyone's phones suddenly pinged with an alert. The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt. A series of messages arrived all ostensibly from the network provider Vodafone. All pro-regime and all with the…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/and-then-the-men-with-guns-tell-you-to-do-it-anyway/"><![CDATA[<p>In early February 2011 <a href="https://www.aljazeera.com/news/2023/1/25/what-happened-during-egypts-january-25-revolution">Egypt was in the middle of a political revolution</a>. One morning, everyone's phones suddenly pinged with an alert.</p>
<blockquote><p>The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt.</p></blockquote>
<p>A <a href="https://www.flickr.com/photos/59098813@N06/5411904816/in/photostream/">series of messages arrived</a> all ostensibly from the network provider Vodafone. All pro-regime and all with the undercurrent of violence.</p>
<p>Why did Vodafone send these messages? Earlier in the week, <a href="https://www.hrw.org/news/2011/01/28/egypt-nationwide-internet-blackout-endangers-rights">all Internet access was cut off</a> now phones were blasting propaganda to the masses.</p>
<p>After the network went down, Vodafone issued a statement saying:</p>
<blockquote><p>It has been clear to us that there were no legal or practical options open to Vodafone, or any of the mobile operators in Egypt, but to comply with the demands of the authorities.</p></blockquote>
<p>Do you have to follow orders? Do you have to obey the law even when it is unjust? Should multinational corporations instruct local executives to be loyal to their parent company or the rulers of the country they live in?</p>
<p>After the messages came in - including promises that "<a href="https://www.theguardian.com/news/blog/2011/feb/03/egypt-protests-live-updates#block-19">The Armed Forces cares for your safety and well being and will not resort to using force against this great nation</a>" - Vodafone Global, safely ensconced in the UK, put out another statement:</p>
<blockquote><p>Under the emergency powers provisions of the Telecoms Act, the Egyptian authorities can instruct the mobile networks of Mobinil, Etisalat and Vodafone to send messages to the people of Egypt. They have used this since the start of the protests. These messages are not scripted by any of the mobile network operators and we do not have the ability to respond to the authorities on their content.</p>
<p>Vodafone Group has protested to the authorities that the current situation regarding these messages is unacceptable. We have made clear that all messages should be transparent and clearly attributable to the originator.</p>
<p><a href="https://web.archive.org/web/20110307151856/http://www.vodafone.com/content/index/press/press_statements/statement_on_egypt.html">Statements - Vodafone Egypt</a></p></blockquote>
<p>A few years later I was at a networking event chatting to a guy. We'd both previously worked for Vodafone. Me in the UK, he in Egypt. I asked him about the incident - he talked about how they built the SMS infrastructure, what they did to secure it, how they prevented spam, and how one day armed men arrived.</p>
<p>I suspect most of us have seen a movie where some flunky in an office refuses the baddies demands to open the safe, and then gets shot in the head. Perhaps you think that's a noble death? He lived with honour and refused to yield! But, in every movie I've seen, the guy's subordinate opens the safe anyway and gets to live.</p>
<p>But we're technologists, right? We can build fail safes and cryptographic proofs and <a href="https://knowyourmeme.com/memes/i-would-simply">simply build infrastructure that can't be abused</a>.</p>
<p>And then the men with guns come and tell you what to do.</p>
<p>I've written before about <a href="https://shkspr.mobi/blog/2013/11/civic-hygiene/">Civic Hygiene</a> - it's the idea that we should be mindful of the ways that our technologies could be misused. The term was coined back in 2010 by the technologist Bruice Schneier</p>
<blockquote><p><a href="https://www.schneier.com/essays/archives/2010/01/us_enables_chinese_h.html">It's bad civic hygiene to build technologies that could someday be used to facilitate a police state.</a></p></blockquote>
<p>But what do we mean by that?</p>
<p>We don't want backdoors in security products - lest hackers break in or evil governments get elected. But we want a way to access our beloved ones' data after they die. It's important that we know that photos haven't been manipulated by propagandists and saboteurs. But we want to send funny memes about that politician we don't like. We don't want police stalking ex girlfriends' cars - but we want dangerous drivers prosecuted.</p>
<p>We want to be alerted about imminent threats, but don't want Governments to use that power for ill.</p>
<p>Way back in the early 2020s, I had a minor role in the UK Government's adoption of <a href="https://github.com/co-cddo/open-standards/issues/73">Common Alerting Protocol</a> the technology which powers cell-broadcast emergency alerts.</p>
<p>Even back then, one of the discussions was around whether the utility of being able to send an unavoidable push notification was worth the risk that someone would send an inappropriate message. Fresh in everyone's minds was the <a href="https://www.bbc.co.uk/news/world-us-canada-42680070">false alarm saying missiles were heading to Hawaii</a>.</p>
<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/2018_Hawaii_missile_alert_cropped.jpeg" alt="Emergency alert. BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL." width="768" height="343" class="aligncenter size-full wp-image-74163">
<p>Too many safeguards means that a genuine alert doesn't get sent in time. Too few safeguards and you can blame "<a href="https://shkspr.mobi/blog/2026/08/book-review-the-field-guide-to-understanding-human-error-by-sidney-dekker/">Human Error</a>" for any mistakes.</p>
<p>I don't know which safeguards are in place for the UK's system - <a href="https://www.ofcom.org.uk/siteassets/resources/documents/about-ofcom/foi/2024/march/emergency-broadcasting?v=331069">and most details are exempt from Freedom of Information requests</a>. But it is both easy and fun to speculate on how such a system might be designed.</p>
<p>The Government generates an alert. It specifies where and when the alert should be sent. It sends that message to the network operators via a secure and private channel. Perhaps they also do some out-of-band verification like having the network operator call a pre-determined phone number to check the message's validity.</p>
<p>At which point, the operator can choose to send the message or not.</p>
<p>Or can they?</p>
<p>In August 2026, the UK government instructed network operators to send this message:</p>
<p><a href="https://www.gov.uk/alerts/14-aug-2026-2"><img src="https://shkspr.mobi/blog/wp-content/uploads/2026/08/fire-alert.webp" alt="Alert about fire risk in the UK." title="Screenshot courtesy of Skylar MacDonald" width="1024" height="851" class="aligncenter size-full wp-image-74164"></a></p>
<p>Did the networks <em>have</em> to send that message? If they thought it wasn't serious enough, could they have refused? As far as I can tell, the law only talks about the fact that operators can disregard "spam" laws in order to send a mass message:</p>
<blockquote><p>A relevant public communications provider (P) may, for the purpose of providing an emergency alert service, disregard the restrictions on the processing of data relating to users or subscribers set out in paragraph (2) if the conditions set out in paragraph (3) are met.</p>
<p>[…]</p>
<p>(3) The conditions are—</p>
<p>(a)P is notified by a relevant public authority that—</p>
<p>(i)an emergency within the meaning of section 1(1) of the Civil Contingencies Act 2004 has occurred, is occurring or is about to occur;</p>
<p><a href="https://www.legislation.gov.uk/uksi/2015/355/pdfs/uksi_20150355_en.pdf">Statutory Instrument 2015 No. 355</a></p></blockquote>
<p>I'm no expert, but I can't see anything in <a href="https://www.ofcom.org.uk/siteassets/resources/documents/manage-your-licence/mobile-wireless-and-broadband/cellular/licences/cellular-licence-vodafone-0249664.pdf?v=368347">the spectrum licence</a> nor in the <a href="https://www.legislation.gov.uk/ukpga/2006/36/contents">Wireless Telegraphy Act</a> which <em>compels</em> operators to process these messages.</p>
<p>The usual British way is to ask people to play nicely and threaten them with regulation if they don't.</p>
<p>Could the networks have refused to send the message about wildfires - or indeed any other message? If your least favourite politician gets their hands on the emergency alert system and tries to abuse it, would you want the networks to stand up to them?</p>
<p>What if the network refuses to send the message because they're worried alerting people about a hurricane will lower the company's profits?</p>
<p>What if armed thugs are sent in and the choice is send the message or die?</p>
<p>I don't know what the answer is here. I think most people agree that it is broadly sensible to have a way to alert the population of emergencies. There's no mass media any more, we're not all listening to a single radio channel, or reading newspapers, or even on the same social media platforms. Sometimes there are emergencies and the Government has a duty to alert people to them.</p>
<p>How would you design a system that simultaneously achieved all these goals:</p>
<ul>
<li>Rapid sending of messages</li>
<li>Careful checking of the content of messages</li>
<li>Ability to quickly target a specific geographic area</li>
<li>Inability to mistakenly send a test message</li>
<li>Requiring strong proof that the message is authentic before sending</li>
<li>Resilient enough to work after significant damage to infrastructure</li>
<li>That networks have the ability to vet and ignore</li>
<li>That networks are compelled to send</li>
<li>Which can only be used for good</li>
<li>And cannot be used for evil.</li>
</ul>
<p>In truth, <a href="https://bsky.app/profile/edent.tel/post/3mt2s2puhuk2x">having experienced fire-starters</a>, I'm not bothered about the contents of this latest message from the UK Government. Given the overstretched fire service and the imminent threat across most of the country, my personal opinion is that it is proportionate.</p>
<p>But it is easy to see why some people feel this might open the gateway to messages which, at best, are irrelevant and, at worst, are similar to the insidious propaganda which appeared on the phones of Egyptians:</p>
<blockquote><p>To every mother-father-sister-brother, to every honest citizen. Preserve this country as the nation is forever.</p></blockquote>
<p>Perhaps you can think of a way to design an alerting system which cannot be abused - but I can't.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Thoughts on visiting the Edinburgh Fringe as a newbie]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/" />
<id>https://shkspr.mobi/blog/?p=74021</id>
<updated>2026-08-16T09:29:11Z</updated>
<published>2026-08-16T11:34:21Z</published>
<category scheme="https://shkspr.mobi/blog" term="EdFringe" />
<summary type="html"><![CDATA[This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer. P…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/"><![CDATA[<p>This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer.</p>
<h2 id="price"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#price">Price</a></h2>
<p>Everything is too expensive. We found student accommodation which was a "mere" £220 per night. I guess that wasn't <em>too</em> exorbitant considering the gouging going on elsewhere - and it did come with a decent breakfast. It was about a 20 minute walk from the Royal Mile, with several performance venues on the way.</p>
<p>The 46 tickets we bought cost us £550 in total - which included a few donations at Free Fringe shows. So an average ticket of £12, which isn't too bad, I guess. You can certainly do things cheaper by only going to free shows and running away when they ask you to pay - but that's a dick move.</p>
<p>£20 for a single hour of stand-up feels like kind of a rip off at times - especially with the mandatory £1.50 booking fee for every ticket. Some shows are a bit cheaper, and Monday/Tuesday has 2-for-1 offers. But it's easy for a couple to spend well over a hundred quid per day seeing 3 or 4 shows.</p>
<p>Festival food and drink prices are inflated - but there's no shortage of supermarkets if you want a meal deal. Restaurants were usual city centre prices. The bars at festival venues were fully taking advantage of their captive audience, but the pubs aren't much cheaper.</p>
<h2 id="the-app"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#the-app">The App</a></h2>
<p>In theory, the app / website is good. In reality they're both a bit frustrating to use. Every time I ticked the box saying "remember my credit card details" and every time it forgot them. Both app and website frequently timed out, failed to add tickets to baskets, and were a bit shonky. The <em>one</em> thing this needs to do is reliably take my money and give it to performers - but it felt like a battle every time.</p>
<p>We missed one show because we couldn't buy a ticket in the app despite being in the queue. The door staff didn't have the ability to sell us a ticket (although some venues can) and directed us to a box office which was dealing with a bunch of people who were bemused that they couldn't pay in dollars.</p>
<p>Inexplicably, the app doesn't have the ability to see show reviews, even though they're present on the website.</p>
<p>There's a good "Nearby Now" feature which is handy when you're exhausted and don't want to trek far. By contrast, there's no easy way to see what's on near the next venue you're going to.</p>
<p>Searching for shows often returns events which are cancelled or sold out.</p>
<p>I wish it were possible to see which shows had undersold and were starting soon. I loved taking a punt on an unknown act who only had half-a-dozen people in the room. Sadly there's no way to grab last-minute deals.</p>
<p>This isn't helped by the total collapse of mobile signal in Edinburgh centre. I tried with a variety of SIMs but frequently only got a trickle of data.</p>
<h2 id="what-to-see"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#what-to-see">What To See</a></h2>
<p>The <abbr title="Fear Of Missing Out">FOMO</abbr> is real! Every show's poster makes it look amazing. The earnest performers desperately handing out leaflets for their own shows are <em>so</em> enthusiastic. Everyone you speak to in a queue has a "must see" which is probably sold out.</p>
<p>We mostly avoided seeing big names. They'll be on telly soon enough or tour down in London. I don't think that act who was big in the 1990s needs my coin as much as some up-and-comer.</p>
<p>You could easily fill a week seeing nothing but Shakespeare in a variety of styles. Or just watch middle-aged white guys have mental breakdowns on stage because they're on their 3rd divorce. Or, as it turns out, fill your boots with Heated Rivalry shows.</p>
<p>We did the tasting menu and had a little bit of everything. It was mostly pretty good with only a few duds.</p>
<h2 id="reviews"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#reviews">Reviews</a></h2>
<p>Even the worst show we saw had a couple of people who declared it the funniest thing ever five stars lol. You can't account for someone else's taste.</p>
<p>I enjoyed <a href="https://shkspr.mobi/blog/tag/EdFringe">writing my reviews</a> - and I hope they were useful to others - but you're mostly on your own when it comes to what's good. I suppose if you wait until later in the festival there will be more of a consensus about what to see.</p>
<p>My philosophy is to take a punt on basically anything that doesn't look too abhorrent. Even if it is shit, there's be something else along in a minute which will be better.</p>
<h2 id="distance"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#distance">Distance</a></h2>
<p>You'll get your 10k steps in before lunchtime - Edinburgh is a delightfully walkable city. With a bit of planning you can walk a straight line from show-to-show. We didn't plan and traipsed back and forth like the little lost tourists we were.</p>
<p>Venues are mostly well sign-posted. Again, the app is a bit crap at pointing them out, but it'll open your mapping app to navigate you there.</p>
<p>Many of the venues are in historic buildings, so don't expect lifts or escalators. Stairs all the way, baby!</p>
<h2 id="harry-potter"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#harry-potter">Harry Potter</a></h2>
<p>Edinburgh seems like an inclusive and trans-friendly city. Half the acts on the Fringe proudly stated their LGBT+ credentials and most venues we went to had gender neutral loos.</p>
<p>And then every other shop proudly boasts it is 100% definitely where JKR got the inspiration for Harry Potter. Tourists are schelpped between "Diagon Alley" and probably-the-cafe-where-she-wrote while slurping down dayglo butterbeers.</p>
<p>Truly the duality of life!</p>
<h2 id="comfort"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#comfort">Comfort</a></h2>
<p>There's an ancient Edinburgh byelaw which prohibits cushions on seats. No chair may be wide enough to accommodate anything other than the skinniest arse. It also places a moratorium on legroom.</p>
<p>Ok, some of the venues were more comfortable than others, but prepare for a bit of backache.</p>
<p>Toilets are plentiful in most venues, and theres no shortage of pubs to pop in to if you need refreshment or relief.</p>
<p>Scotland isn't known for its heat, but some of the venues desperately need air-conditioning in their foyers and auditoriums. A few were handing out free water to the swealtering punters - but probably best to bring your own</p>
<h2 id="would-i-come-here-again"><a href="https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#would-i-come-here-again">Would I Come Here Again?</a></h2>
<p>Yeah! I reckon so! Probably not next year, and probably with more of a plan about which "must sees" I wanted to see.</p>
<p>Staying closer to the centre is more expensive, but might have made it easier to see some if the shows later in the night.</p>
<p>There is <em>so</em> much talent, <em>so</em> much variety, and <em>so</em> much joy in the city that it becomes rather infectious.</p>
<p>If you can afford the train fare, hotel costs, tickets, booking fees, pints, chips and all the other people desperate to stick their hands into your wallet - then it is a great adventure.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Book Review: Slags by Emma Jane Unsworth ★★★⯪☆]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/book-review-slags-by-emma-jane-unsworth/" />
<id>https://shkspr.mobi/blog/?p=72687</id>
<updated>2026-06-29T19:43:11Z</updated>
<published>2026-08-15T11:34:42Z</published>
<category scheme="https://shkspr.mobi/blog" term="Book Club" /><category scheme="https://shkspr.mobi/blog" term="Book Review" />
<summary type="html"><![CDATA[I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia. It reminds me of this excellent essay by Marie Le Conte about consent. What can a teenage girl…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/book-review-slags-by-emma-jane-unsworth/"><![CDATA[<img src="https://shkspr.mobi/blog/wp-content/uploads/2026/06/slags.webp" alt="Book cover featuring a teenage girl smoking." width="200" class="alignleft size-full wp-image-72688">
<p>I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia.</p>
<p>It reminds me of this excellent <a href="https://youngvulgarian.substack.com/i/152315586/a-column">essay by Marie Le Conte about consent</a>. What can a teenage girl consent to? What will fuck her up for years to come? What if she doesn't mind being a <em>little</em> fucked up?</p>
<p>The prose is amazing, the plotting perfectly paced, and the denouement satisfying - with lots of retrospectives "Oh! I get it now"s.</p>
<p>Despite the hectic and hilarious story, I still felt a little sordid reading it. There's a streak of sadness running through it, intertwined with some unbearably heartbreaking poetry.</p>
<blockquote><p>It’s always raining and there’s nothing to do except dream and they don’t even give you much time to do that with all the coursework.</p></blockquote>
<p>It is entertaining and fun - but you need a strong stomach and a casual disregard for the overall happiness of your protagonists.</p>
<p>One note - there are a few odd / broken styles in the ePub. Nothing too disruptive, but some passages have a slightly smaller font size for no discernable reason.</p>
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</entry>
<entry>
<author>
<name>Terence Eden</name>
<uri>https://edent.tel/</uri>
</author>
<title type="html"><![CDATA[Edinburgh Fringe: Target Audience ★★★★★]]></title>
<link rel="alternate" type="text/html" href="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-target-audience/" />
<id>https://shkspr.mobi/blog/?p=74018</id>
<updated>2026-08-14T18:10:20Z</updated>
<published>2026-08-14T18:45:41Z</published>
<category scheme="https://shkspr.mobi/blog" term="comedy" /><category scheme="https://shkspr.mobi/blog" term="EdFringe" /><category scheme="https://shkspr.mobi/blog" term="Theatre Review" />
<summary type="html"><![CDATA[Easily the best show I've seen at the Fringe. For plot-related reasons, a television company asks a literary genius to create a "pro-weapons sitcom". It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night. All four of the cast are spectacular. Turning the…]]></summary>
<content type="html" xml:base="https://shkspr.mobi/blog/2026/08/edinburgh-fringe-target-audience/"><![CDATA[<p>Easily the best show I've seen at the Fringe.</p>
<p>For plot-related reasons, a television company asks a literary genius to create a "pro-weapons sitcom".</p>
<p>It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night.</p>
<p>All four of the cast are spectacular. Turning the sometimes-stock characters into powerful avatars. The amoral Zuckerbergian horror of data driven decision making is the perfect manure in which to grow comedy roses.</p>
<p>It stands well against any classic farce and I hope it tours until the end of the world.</p>
<p>A special shout out to the Pleasance Above for being the most comfortable venue in Edinburgh! Raked auditorium, cushioned seats, and air conditioning all make for a delightful theatrical experience.</p>
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"id": "https://shkspr.mobi/blog/?p=74622",
"title": "ActivityPub - Is it worth defending against replay attacks and message/signature time skew?",
"description": "Here's a problem that I've found with ActivityBot - my little ActivityPub server. Sometimes it receives messages which were originally sent months ago. Why does that happen and is it risky to accept and process them? My tl;dr is that it probably isn't worth worrying about. But I'd love someone to tell me why I'm wrong. Here's my thinking: Table of ContentsCausesIs that a problem?What are we…",
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"published": "2026-09-08T11:34:51.000Z",
"updated": "2026-09-08T09:42:04.000Z",
"content": "<p>Here's a problem that I've found with <a href=\"https://gitlab.com/edent/activity-bot/\">ActivityBot</a> - my little ActivityPub server. Sometimes it receives messages which were originally sent <em>months</em> ago. Why does that happen and is it risky to accept and process them?</p>\n\n<p>My tl;dr is that it <em>probably</em> isn't worth worrying about. But I'd love someone to tell me why I'm wrong.</p>\n\n<p>Here's my thinking:</p>\n\n<p></p><nav role=\"doc-toc\"><menu><li><h2 id=\"table-of-contents\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#table-of-contents\">Table of Contents</a></h2><menu><li><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes\">Causes</a></li><li><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem\">Is that a problem?</a></li><li><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against\">What are we trying to protect against?</a></li><li><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together\">Putting it all together</a></li><li><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it\">No! You're wrong and I can prove it!</a></li></menu></li></menu></nav><p></p>\n\n<h2 id=\"causes\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#causes\">Causes</a></h2>\n\n<p>All ActivityPub messages should have a \"published\" timestamp in their body. Some will have an \"updated\" timestamp. That tells you, unsurprisingly, when the message is alleged to have been originally published or updated. That time might be very different to the time you receive the message.</p>\n\n<p>There are, I think, three different reasons why a server might receive a message which has an out-of-date timestamp.</p>\n\n<p>The first is that sometimes servers are just slow. Processing thousands of messages at the same time means that some of those messages take a while to send. <a href=\"https://shkspr.mobi/blog/2023/09/how-far-did-my-post-go-on-the-fediverse/\">ActivityPub is one big chain-mail</a> so it can take several minutes for a message to be sent to all your followers.</p>\n\n<p>Similarly, your server might be slow. If it doesn't acknowledge receipt of a message, the original server will try sending it again. Sometimes that can take a while.</p>\n\n<p>Finally, some servers take a relaxed view of standards. They send an update to an old message but keep the original publication date. Ideally, they'd use an \"updated\" timestamp but quite often they don't.</p>\n\n<p>For the purposes of checking the legitimacy of the message, <strong>you do not need to check when a message says it was published or updated</strong>. You might want to check it isn't an <em>obviously</em> bogus date like far in the future or impossibly far in the past - but that's up to you.</p>\n\n<p>It is normal that your server receives messages which appear to have been published at a totally different time from now.</p>\n\n<h2 id=\"is-that-a-problem\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#is-that-a-problem\">Is that a problem?</a></h2>\n\n<p><em>Probably</em> not.</p>\n\n<p>As described above, there are various reasons why a message may be delayed in transit - or may appear to come from the distant past.</p>\n\n<p>What we <em>can</em> check is when the message was cryptographically signed by the sending server. This is independent of its published or updated timestamp.</p>\n\n<p>HTTP requests to your server will have a <code>date</code> header which looks like <code>Tue, 01 Sep 2026 15:54:21 GMT</code> - this is in the slightly peculiar and Anglocentric <a href=\"https://www.rfc-editor.org/info/rfc5322/#section-3.3\">RFC 5322 format</a>.</p>\n\n<p>New style RFC 9421 headers will also have a <code>signature-input</code> header which will contain something like <code>created=1788278061</code>. That uses the slightly obscure <a href=\"https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16\">UNIX / POSIX time</a> which counts seconds since the \"Epoch\" of 1st January 1970.</p>\n\n<p>If you <a href=\"https://www.epochconverter.com/\">convert the UNIX time</a> to something more modern, you should get an <em>identical</em> value to the <code>date</code> header.</p>\n\n<p>But that isn't always the case. For example, <a href=\"https://www.rfc-editor.org/rfc/rfc9421.html#:~:text=Tue%2C%2020%20Apr%202021%2002%3A07%3A55%20GMT,-Content%2DType\">the RFC 9421 standard gives this example</a>:</p>\n\n<pre><code class=\"language-_\">Date: Tue, 20 Apr 2021 02:07:55 GMT\n\"@signature-params\": (\"@method\" \"@authority\" \"@path\" \\\n \"content-digest\" \"content-length\" \"content-type\")\\\n ;created=1618884473;keyid=\"test-key-rsa-pss\"\n</code></pre>\n\n<p>Converting <code>1618884473</code> to normal time gives Tue, 20 Apr 2021 02:07:<strong>53</strong> - a two second difference.</p>\n\n<p>If the <code>date</code> and <code>created</code> values differ significantly - that may indicate that the message is untrustworthy. Or that there was a delay between the signing and the sending.</p>\n\n<p>The spec says:</p>\n\n<blockquote><p>The Date header field value represents the timestamp of the HTTP message. However, the creation time of the signature itself is encoded in the created signature parameter. These two values can be different, depending on how the signature and the HTTP message are created and serialized. Applications processing signatures for valid time windows should use the created signature parameter for such calculations. An application could also put limits on how much skew there is between the Date field and the created signature parameter, in order to limit the application of a generated signature to different HTTP messages.</p>\n\n<p><a href=\"https://www.rfc-editor.org/rfc/rfc9421.html#section-7.2.4\">7.2.4. Choosing Signature Parameters and Derived Components over HTTP Fields</a></p></blockquote>\n\n<p>But, of course, it doesn't tell you how much skew is problematic. It's up to you how much skew you're prepared to accept.</p>\n\n<p>So that's the difference between the sent time and the signed time. The next time to check is your own. As we've discussed, sometimes servers are slow sending things out. Would you accept a request that was signed five minutes ago? Five days ago? Five months ago? What amount of difference is dangerous?</p>\n\n<p>Here's what various services and sages have to say:</p>\n\n<h3 id=\"mastodon\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#mastodon\">Mastodon</a></h3>\n\n<blockquote><p>The request contains a Date header. Compare it with current date and time within a reasonable time window to prevent replay attacks.</p>\n\n<p><a href=\"https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/\">How to make friends and verify requests</a></p></blockquote>\n\n<p>What is \"reasonable\"? The <a href=\"https://github.com/mastodon/mastodon/blob/89bc0eb42609463d4b11e1604dacc37332a0f5ab/app/lib/signed_request.rb#L5\">source code</a> suggests one hour.</p>\n\n<h3 id=\"grishka\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#grishka\">Grishka</a></h3>\n\n<blockquote><p>Time in the Date header must differ from the recipient server’s clock by no more than 30 seconds</p>\n\n<p><a href=\"https://grishka.me/blog/activitypub-from-scratch/\">A bare-minimum ActivityPub server from scratch</a></p></blockquote>\n\n<h3 id=\"evan-prodromou\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#evan-prodromou\">Evan Prodromou</a></h3>\n\n<blockquote><p><code>static #maxDateDiff = 5 * 60 * 1000 // 5 minutes</code></p>\n\n<p><a href=\"https://github.com/evanp/activitypub-bot/blob/main/lib%2Fhttpsignatureauthenticator.js#L8\">activitypub-bot</a></p></blockquote>\n\n<h3 id=\"swicg\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#swicg\">SWICG</a></h3>\n\n<blockquote><p>The standards don't give a concrete time window to use for this comparison. In practice, an hour plus a few minutes buffer in either direction may be a good value, to account for both clock skew and differences in time zone/daylight savings time configuration across systems.</p>\n\n<p><a href=\"https://swicg.github.io/activitypub-http-signature/#how-to-verify-a-signature\">How To Verify a Signature</a></p></blockquote>\n\n<h3 id=\"others\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#others\">Others</a></h3>\n\n<p>Without naming names, it looks like a bunch of popular servers don't check whether there's a significant difference between the date the request was signed and the date it was received.</p>\n\n<h3 id=\"summary\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#summary\">Summary</a></h3>\n\n<p>Various documents and implementations recommend anything between 30 seconds to \"a bit more than 60 minutes\". Or they just ignore any date difference.</p>\n\n<p>What's the right answer? What happens if the signed date is significantly different from the current date?</p>\n\n<h2 id=\"what-are-we-trying-to-protect-against\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#what-are-we-trying-to-protect-against\">What are we trying to protect against?</a></h2>\n\n<p>Replay Attacks. Suppose someone is listening to the communications between the sending server and your server. They copy the message that is sent to you. Later they send it again!</p>\n\n<p>At this point, you might be thinking \"so what?\" and… I'm inclined to agree with you!</p>\n\n<p>What's the worst that could happen if you received the same message multiple times? Two things that I can think of.</p>\n\n<p>Firstly, it might <em>not</em> be the same message. It is possible to send a new message but with old headers. An attacker could make someone post \"I hate Taylor Swift\" against their will and watch as legions of fans disembowel the victim.</p>\n\n<p>Except, I don't think this is likely. The signature in the header contains a hash of the message being sent. If you are properly validating the signature, a changed message will have a different hash from the one in the original message. You don't need to check timestamps, you just need to check if the hashes match.</p>\n\n<p>Secondly, <a href=\"https://www.freecodecamp.org/news/idempotence-explained\">idempotence</a>. That's a fancy word for \"pressing the button multiple times should only result in one action\".</p>\n\n<p>What happens if a user appears to send you multiple \"like\" messages for a single post? You only record one like.</p>\n\n<p>What if they send multiple messages with the same content? Well, each will have a unique ID in the message - so you only post it once.</p>\n\n<p>What if they send multiple <em>anythings</em>? I can't think of any ActivityPub action which would not be idempotent.</p>\n\n<p>About the worst thing I can think of is this:</p>\n\n<ul>\n<li>Alice sends a message to you saying \"I want to follow Bob\".</li>\n<li>Mallory intercepts this message.</li>\n<li>You record Alice is now following Bob.</li>\n<li>Alice sends a message to you saying \"I want to <em>unfollow</em> Bob\".</li>\n<li>You record the severed relationship.</li>\n<li>Mallory replays the original follow message.</li>\n<li>You record Alice is now following Bob.</li>\n</ul>\n\n<p>It's also possible the following could happen:</p>\n\n<ul>\n<li>Alice posts a message saying \"I love The Beatles\".</li>\n<li>You record Alice's message and display it on the timeline.</li>\n<li>Alice updates her post to say \"I love the Rolling Stones\".</li>\n<li>Mallory intercepts this message.</li>\n<li>You record Alice's updated message and display the new version on the timeline.</li>\n<li>Alice updates her post yet again to say \"I love the Spice Girls\".</li>\n<li>You record Alice's updated message and display the new version on the timeline.</li>\n<li>Mallory replays the original update message.</li>\n<li>You now display that Alice loves the Stones rather than Spice Girls.</li>\n</ul>\n\n<p>Perhaps the same can happen with like/unlike, block/unblock, boost/unboost.</p>\n\n<p>But none of that is significantly prevented by checking the date.</p>\n\n<p>Ultimately, it is up to your sever to check the unique ID of each message and refuse to action any repeated messages. You may not want to trust the unique ID which is sent with the message. If that's the case, you can calculate your own - perhaps using a hash of the contents, the signature, or some other process which will generate an ID based on the message.</p>\n\n<h2 id=\"putting-it-all-together\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#putting-it-all-together\">Putting it all together</a></h2>\n\n<p>Here's what you need to do to prevent replay attacks:</p>\n\n<ol>\n<li>Independently calculate the hash of the message received.</li>\n<li>Validate that your calculated hash matches the hash sent in the message's HTTP headers.\n\n<ul>\n<li>If not, this is a potential replay attack and the message must be ignored.</li>\n</ul></li>\n<li>Verify that the signature received in the message's HTTP headers includes the message hash and is cryptographically valid.\n\n<ul>\n<li>If not, the signature is invalid and the message must be ignored.</li>\n</ul></li>\n<li>Has the received message's unique ID already been processed?\n\n<ul>\n<li>If so, refuse to process it again.</li>\n</ul></li>\n</ol>\n\n<p>I don't see what checking the timestamp of the HTTP signature has to do with anything. Someone who has access to the original messages and their headers could send them milliseconds after the original delivery.</p>\n\n<p>I think it is probably <em>pragmatic</em> to give messages 60ish minutes grace before dropping them. Delays happen, but anything more significant than an hour <em>might</em> indicate a attack. But, equally, might just mean that the Internet is having a slow day.</p>\n\n<p>If you are correctly checking signatures and hashes, I don't think you need to worry about skew between signature date and delivery date.</p>\n\n<h2 id=\"no-youre-wrong-and-i-can-prove-it\"><a href=\"https://shkspr.mobi/blog/2026/09/activitypub-is-it-worth-defending-against-replay-attacks-and-message-signature-time-skew/#no-youre-wrong-and-i-can-prove-it\">No! You're wrong and I can prove it!</a></h2>\n\n<p>Please tell me where I have erred! Stick a comment in the box or drop me an email. If I've made a massive or subtle mistake, I'd love to know what.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74622&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "ActivityBot",
"term": "ActivityBot",
"url": "https://shkspr.mobi/blog"
},
{
"label": "ActivityPub",
"term": "ActivityPub",
"url": "https://shkspr.mobi/blog"
},
{
"label": "http",
"term": "http",
"url": "https://shkspr.mobi/blog"
},
{
"label": "security",
"term": "security",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74588",
"title": "The purpose of DNS is to spread scams",
"description": "I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people …",
"url": "https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/",
"published": "2026-09-06T11:34:20.000Z",
"updated": "2026-09-05T17:12:13.000Z",
"content": "<p>I imagine everyone here has received an unsolicited message telling them that their tax is overdue and that they urgently need to visit Genuine-Tax-Payment-Website.fart or that a parcel is delayed at customs and you can pay a small sum for its release at Almost-The-Right-Acronym.ak</p>\n\n<p>You know it is a scam. Most people just mark as spam and move on with their day. But a significant number of people don't. They hastily visit the site, tap in their credit card details, give it their mother's maiden name, confirm address, upload a nude selfie, and only then realise that they've been had.</p>\n\n<p>The Internet works at pretty close to the speed of light. You can register a .uk domain and a minute later it's accessible from the other side of the planet. Brilliant for users who want to quickly launch a website. Also brilliant for abusers who want to launch a spam campaign.</p>\n\n<p>By the time enough people have reported the scammers' domain as suspicious, it is too late. In the time it takes for a registrar to disable the domain, or for its name to make its way to the <a href=\"https://safebrowsing.google.com/\">Safe Browsing List</a>, a million messages have already been sent and enough people have handed over their details.</p>\n\n<p>We're told that \"<a href=\"https://en.wikipedia.org/wiki/The_purpose_of_a_system_is_what_it_does\">the purpose of a system is what it does</a>\". At the moment, the Domain Name System's purpose seems to be a vector for criminals to run scams on people at a terrifyingly high rate.</p>\n\n<h2 id=\"how-big-is-this-problem\"><a href=\"https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#how-big-is-this-problem\">How big is this problem?</a></h2>\n\n<p>BIG!</p>\n\n<p>There's a great blog post by Andrew Campling which reports on this startling claim:</p>\n\n<blockquote><p>The study found that at least 10% of all new gTLD domain names registered during the year had subsequently appeared on security blocklists by the time of analysis. It estimated that, taking account of subsequent blocklisting and associated domains not themselves blocklisted, the share of names registered by malicious actors <strong>may be closer to 20%</strong>.</p>\n\n<p><a href=\"https://labs.ripe.net/author/andrew_campling/dns-abuse-and-criminal-infrastructure-beyond-definitions-and-blocklists/\">DNS Abuse and Criminal Infrastructure: Beyond Definitions and Blocklists</a> (emphasis added)</p></blockquote>\n\n<p>That links to a presentation by Interisle which contains some rather shocking statistics (<a href=\"https://www.icann.org/en/blogs/details/looking-beyond-the-numbers-understanding-malicious-domain-registration-data-10-08-2026-en\">albeit with disputed methodology</a>). It looks at <em>generic</em> Top Level Domains (gTLD) - those are things like .com and .fun rather than country code TLDs (ccTLD) like .uk and .de.</p>\n\n<p>It says 85 million new registrations of gTLDs were made in 2025. Of those 8.5 million were added to blocklists by May 2025. It reckons that a 10% abuse rate is the likely floor for these numbers and it's probably closer to 20%. One in five newly registered domains with a gTLD are scams. That's a bloody crisis.</p>\n\n<p>13 TLDs had more than 50% of their registrations blocklisted.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/gTLDs.webp\" alt=\"Table listing the top 13 generic Top-Level Domains (gTLDs) with the highest percentage of blocklisted, malicious new domains created in 2025. Ranked from highest to lowest blocklist percentage, top entries include .LOCKER (72.9%), .LGBT (72.2%), and .TOWN (70.2%). The table detail includes TLD operators, registration totals, and specific malicious domain metrics.\" width=\"1162\" height=\"954\" class=\"aligncenter\">\n\n<p>I can understand why .bid and .loan are popular with scammers. But why .mobi?! What did I ever do to you, eh?</p>\n\n<p>Who are the scammers registering these through?</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/registrars.webp\" alt=\"List of registrars. NameCheap, Gname, Dynadot, NameSilo, GoDaddy.\" width=\"910\" height=\"390\" class=\"aligncenter\">\n\n<p>Ah, our old friends at NameCheap. See <a href=\"https://shkspr.mobi/blog/2021/05/why-do-scammers-love-namecheap/\">Why do scammers love NameCheap?</a></p>\n\n<p>If those five registrars had more effective policies, it might significantly dent the scammers' ability to ply their devious wares. Or they might just move on to other registrars.</p>\n\n<p>As the report points out:</p>\n\n<blockquote><p>suspension rates for blocklisted domains were 7.4% to 16.3%.</p></blockquote>\n\n<p><a href=\"https://interisle.net/s/FullReport_MaliciousRegistrationsintheDomainNameMarket_2026_rev.pdf\">The full report is on the Interisle website</a>.</p>\n\n<h2 id=\"what-can-be-done\"><a href=\"https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-can-be-done\">What can be done?</a></h2>\n\n<p>I don't know.</p>\n\n<p>In the first instance, it might make sense for registrars to do strong Know Your Customer (KYC) checks on anyone buying a domain. But that stops anyone who wants to anonymously register <code>I-Hate-Nintendo.whatever</code> without risking the wrath of Intellectual Property lawyers.</p>\n\n<p>Also, criminals have access to stolen money and stolen cards. They can convince a hapless mule to register a domain on the criminals' behalf.</p>\n\n<p>Registrars could ask for an escrow payment. Pay €9 for the domain name put €900 in escrow. If your domain appears on a blocklist within the year, you forfeit the money. Criminals with stolen funds are unlikely to care but it would probably put off lots of people from getting a new domain.</p>\n\n<p>There are various banned words and phrases depending on the TLD. For example, <a href=\"https://shkspr.mobi/blog/2024/07/ss-tld-opening-for-direct-registrations/\">South Sudan</a> has a list of political words which they don't want associated with their .ss ccTLD.</p>\n\n<p>But if one gTLD bans a word, a different one might not. A scammer doesn't care if the gTLD is .arse or .elbow - they just want the start of the domain to look legitimate.</p>\n\n<p>Some registrars have strings that they don't allow. In fairness to NameCheap, when I tried to register <code>dwp-payments-gov-uk.pizza</code> it told me that domain was banned. It wouldn't let me get any gTLD with that name.</p>\n\n<p>But all it takes is one registrar to be slightly lax and the scammers get through. Increasing the complexity of the rules is also a hell of a burden on smaller registrars.</p>\n\n<p>Besides, it's pretty easy to get a generic enough looking domain and stick the confusing bit on a subdomain. Here are a clutch mentioned in the report:</p>\n\n<ul>\n<li><code>https://gov.uk-dwpaph.bond/uk/</code></li>\n<li><code>https://gov.uk-dwpcjh.bond/uk/</code></li>\n<li><code>https://gov.uk-dwpclc.bond/uk</code></li>\n<li><code>https://gov.uk-dwpclw.bond/uk</code></li>\n<li><code>https://gov.uk-dwpclj.bond/uk/</code></li>\n</ul>\n\n<p>Perhaps there ought to be a delay before a new domain goes live to allow people to object to it? That would give governments, banks, delivery companies, and a dozen more \"important\" organisations a right to veto any \"dodgy\" looking domain.</p>\n\n<p>But suppose someone wants to register <code>gov-uk-stole-my-horse.horse</code> to protest the government's cruel policy of stealing horses - is that a legitimate use of a domain? What if the Darwin Pensioner Divas - a group of elderly singers - want to take payments for their new album of goth/punk covers, can the DPD delivery company veto <code>dpd-payments.music</code>?</p>\n\n<p>Do we want a domain name system where powerful companies control exactly which domains we can register? If I have an idea for a domain on a Friday night do I have to wait until Monday before it can be launched? Are those companies realistically able to parse millions of domains per year and have a low false-positive rate?</p>\n\n<p>All of these things are possible - but all of them come with an impact on legitimate users. To be clear, I don't know what the right answer is.</p>\n\n<h2 id=\"what-is-icann-doing-about-it\"><a href=\"https://shkspr.mobi/blog/2026/09/the-purpose-of-dns-is-to-spread-scams/#what-is-icann-doing-about-it\">What is ICANN doing about it?</a></h2>\n\n<p>Lots! It has been a few years since I've been to an ICANN meeting, but even back then the topic of abuse was high on the agenda. They appear to be looking at ways to coordinate abuse reports between various entities, along with some other policies which should hopefully work.</p>\n\n<p>There are two salient points from <a href=\"https://hosted-files.sched.co/icann86/b3/TRANSC_I86SQV_Mon08June2026__GNSO-DNS%20Abuse%20Mitigation%20PDP%201%20%281%20of%204%29-en.pdf\">one of the discussions held at the recent meeting</a></p>\n\n<blockquote><p>If anybody thinks that in our current age of AI and as we move into different kinds of computing, DNS abuse is going to numerically stay steady and we will have a downward effect on that baseline 2027 number. I'm not sure that that's an accurate assumption. I think it's going to be the other thing, which is […] it's going to be easier to abuse the DNS.</p></blockquote>\n\n<p>And</p>\n\n<blockquote><p>Abusers are going to abuse because it's just too lucrative, because no matter what we do, they will find the way to make profit off of that, and will try to circumvent everything that we do. That is not a reason not to do it, though.</p></blockquote>\n\n<p>Quite!</p>\n\n<p>As I said, I don't know the answer to this. What I do know is, much like <a href=\"https://shkspr.mobi/blog/2025/08/is-it-possible-to-allow-sideloading-and-keep-users-safe/\">Android's app ecosystem being a haven for scammers</a>, DNS is facing a crisis. When trust in a system goes, only chaos follows.</p>\n\n<p>I don't want to live in a world where I have to show my passport and pay thousands of pounds to register a domain which is only available after being vetted by private interests. But I also don't want to live in a world where scammers have effectively no deterrent from abusing millions of people.</p>\n\n<p>The purpose of a system is what it does. I hope DNS's purpose can become less dangerous while still remaining open.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74588&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "ICANN",
"term": "ICANN",
"url": "https://shkspr.mobi/blog"
},
{
"label": "internet",
"term": "internet",
"url": "https://shkspr.mobi/blog"
},
{
"label": "scam",
"term": "scam",
"url": "https://shkspr.mobi/blog"
},
{
"label": "spam",
"term": "spam",
"url": "https://shkspr.mobi/blog"
},
{
"label": "tld",
"term": "tld",
"url": "https://shkspr.mobi/blog"
},
{
"label": "web",
"term": "web",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74686",
"title": "Book Review: The Passing of the Dragon and Other Stories by Ken Liu ★★★★☆",
"description": "This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured. What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a…",
"url": "https://shkspr.mobi/blog/2026/09/book-review-the-passing-of-the-dragon-and-other-stories-by-ken-liu/",
"published": "2026-09-05T11:34:47.000Z",
"updated": "2026-09-05T09:22:57.000Z",
"content": "<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/09/9781035929306.webp\" alt=\"Book cover.\" width=\"200\" class=\"alignleft\">\n\n<p>This is a gorgeous set of short stories - and a good deal more accessible than some of the heavyweight prose Liu has previously been involved with. Some of the stories contain sentences which are complex jewels to be savoured.</p>\n\n<p>What I particularly like is the way he moves between almost-prosaic Earth-bound stories to the the most extraordinary flights of fancy. One story might be set in a downtown art gallery, the next in the ice-rings of a far-off planet. The creeping feeling of senescence haunts the reader as they flit from story to story.</p>\n\n<p>Much like his full-length novel <a href=\"https://shkspr.mobi/blog/2025/09/book-review-all-that-we-see-or-seem-by-ken-liu/\">All That We See or Seem</a>, Liu has an incredible knack for tapping in to modern fears and weaving tall tales around them. There's a tenderness in all his character - even when a couple of the stories go nowhere, it is still pleasant to spend time in the worlds he has created.</p>\n\n<p>It is, perhaps, missing a cohesive theme - the dragons come and go throughout the stories. Nevertheless, a compelling work chock full of fantastical ideas.</p>\n\n<p>If you're in the mood for a wide and varied selection of stories, this is well worth picking up.</p>\n\n<p>Many thanks to NetGalley for the review copy. Passing of the Dragon is available to buy now.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74686&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "Book Review",
"term": "Book Review",
"url": "https://shkspr.mobi/blog"
},
{
"label": "NetGalley",
"term": "NetGalley",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Sci Fi",
"term": "Sci Fi",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74429",
"title": "A reasonably practical guide to validating RFC 9421 HTTP Signatures for ActivityPub in PHP",
"description": "If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers. This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild. Shut Up And Show Me The Code! OK, wow, no…",
"url": "https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/",
"published": "2026-09-03T11:34:12.000Z",
"updated": "2026-09-04T13:36:29.000Z",
"content": "<p>If you're reading this, you've probably been hitting your head against a brick wall trying to parse and decipher the new HTTP Signatures sent by Mastodon and other Fediverse servers.</p>\n\n<p>This is a basic and somewhat incomplete guide to accepting these signatures. I'm sure there are various gotchas, but it works with the signatures I've seen in the wild.</p>\n\n<h2 id=\"shut-up-and-show-me-the-code\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#shut-up-and-show-me-the-code\">Shut Up And Show Me The Code!</a></h2>\n\n<p>OK, wow, no need to be a dick about it! Here's how I validated a real signature that my server received. This requires PHP 8.4 or newer.</p>\n\n<pre><code class=\"language-php\">$verified = openssl_verify(\n data: '\"@method\": POST\n\"@target-uri\": https://example.viii.fi/inbox\n\"content-digest\": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:\n\"@signature-params\": (\"@method\" \"@target-uri\" \"content-digest\");created=1787780262;keyid=\"https://mastodon.social/users/Edent#main-key\"',\n signature: base64_decode( \"sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==\" ),\n public_key: \"-----BEGIN PUBLIC KEY-----\\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\\n3QIDAQAB\\n-----END PUBLIC KEY-----\\n\",\n algorithm: \"sha256\"\n);\n\necho $verified;\n</code></pre>\n\n<p>Copy and paste that into PHP and you should see that <code>$verified</code> is true.</p>\n\n<h2 id=\"now-explain-the-code\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#now-explain-the-code\">NOW EXPLAIN THE CODE</a></h2>\n\n<p>Say please.</p>\n\n<h2 id=\"please\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#please\">PLEASE!!!</a></h2>\n\n<p>Along with the message sent to your server, you will have received HTTP headers like this:</p>\n\n<pre><code class=\"language-_\">content-digest: sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:\nsignature: sig1=:sIfmNsM/Q8iG6AJlne1IkZVjQSVFDEYIPsnoSOXQY+W3Eb4+SOn9o4J5SQmFOP+Jecjf3ioFwUdsrFjAGkUUOHPvSbNWkGKtNuGm+C6r3aI3JBCFGPqX3ITgZYV76CF7JJJ5hPGaG8YH/XdmxVIeFfD3M39FQCncMyyq7xJJvwKKP1mzS5s1vNQie8hbQ9owRjtqvoWcmM9GEYCUHNcMPLjZc+CBrj8sfBbNTYgIFI4UtirOaRJvYymxXjmXuzeVYxQujMjAjgobxQ8QFv0zlYsHk+gS5EYyafpJG9zmfCFSoF9+ZwqKNADmuADbISD9LZIH/bmkPoNXhxaeFPqYog==:\nsignature-input: sig1=(\"@method\" \"@target-uri\" \"content-digest\");created=1787780262;keyid=\"https://mastodon.social/users/Edent#main-key\"\n</code></pre>\n\n<p>The <code>signature-input</code> tells you how to construct a \"Signature Base\". You have to build a text string which places the various components in the order specified and separated with a newline:</p>\n\n<pre><code class=\"language-_\">\"@method\": POST\n\"@target-uri\": https://example.viii.fi/inbox\n\"content-digest\": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:\n\"@signature-params\": (\"@method\" \"@target-uri\" \"content-digest\");created=1787780262;keyid=\"https://mastodon.social/users/Edent#main-key\"\n</code></pre>\n\n<p>Where <code>@method</code> is the HTTP method used to send data to your server (usually <code>GET</code> or <code>POST</code>), and <code>@target-uri</code> is the URl the message was sent to (usually your inbox).</p>\n\n<p>The <code>publicKey</code> is slightly trickier. As you can see, the <code>signature-input</code> ends with <code>keyid=\"https://mastodon.social/users/Edent#main-key</code></p>\n\n<p>If you make a signed request to that URl, you'll get back an ActivityPub Actor document. It will look something like this:</p>\n\n<pre><code class=\"language-json\">{\n \"@context\": [\n \"https://www.w3.org/ns/activitystreams\",\n \"https://w3id.org/security/v1\",\n ],\n \"id\": \"https://mastodon.social/users/Edent\",\n \"webfinger\": \"Edent@mastodon.social\",\n \"type\": \"Person\",\n \"name\": \"Terence Eden\",\n \"publicKey\": {\n \"id\": \"https://mastodon.social/users/Edent#main-key\",\n \"owner\": \"https://mastodon.social/users/Edent\",\n \"publicKeyPem\": \"-----BEGIN PUBLIC KEY-----\\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsYMEs4waqk/6gaS+xn1T\\nYygElTtNIFNkBcEdEBMaeoGVhyZiVKtSjJCS4z+X+394PKvcfSTcFILIt2GI2jOB\\nHD0M2fFgxc8mmdSdCQkgEh9jF3bFI3kopDvzYf726iioYKlHXKpfPKvFt7EJgKH7\\naCtS25NQkek3YUd6y3VBcT3R6Xhze9P3QNoZMIsFXklgXDKj+EllfbUqLf1vxt3s\\nmD9ETxy2bJi9FheE0uY2WhARn49XAvwczM5Wzt+zqxVEtgpi5v2+ZZAVKhDnJkiC\\nCCuI6hrSnKNIx/5mSlX0a0S5h5d03djrCkYsqmwelu01rhOXP2grsz4BXp0y2wrO\\n3QIDAQAB\\n-----END PUBLIC KEY-----\\n\"\n },\n</code></pre>\n\n<p>The <code>publicKeyPem</code> is the string you need. There's no need to convert the <code>\\n</code> to literal newlines.</p>\n\n<h2 id=\"is-that-it\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#is-that-it\">Is that it?</a></h2>\n\n<p>Not quite! All we've done so far is verify the headers. It is possible that these are genuine headers but attached to a fraudulent body.</p>\n\n<p>This takes us back to the header <code>\"content-digest\": sha-256=:tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=:</code></p>\n\n<p>That says that the body of the message sent has a Base64 encoded SHA256 hash of <code>tFdB/ENGczHMlZMDb66pXoUi2d0OqH2iBHdnN/WV1mc=</code>.</p>\n\n<p>To calculate your own content digest in PHP:</p>\n\n<pre><code class=\"language-php\">$input = file_get_contents( \"php://input\" );\n$digestCalculated = base64_encode(\n hash(\n algo: \"sha256\",\n data: $input,\n binary: true\n )\n);\n</code></pre>\n\n<p>Does your digest match the one sent along with the headers? If not, something dodgy is going on.</p>\n\n<h2 id=\"putting-it-all-together\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#putting-it-all-together\">Putting it all together</a></h2>\n\n<p>The steps are:</p>\n\n<ol>\n<li>Get the headers.</li>\n<li>Get the body.</li>\n<li>From the headers' <code>content-digest</code> extract the algorithm and hash.</li>\n<li>Using the body, calculate your own hash using the algorithm from <code>content-digest</code>.</li>\n<li>Does your hash match the sent hash? If not, stop. If so, proceed.</li>\n<li>From the headers' <code>signature</code> extract the base64 encoded signature.</li>\n<li>From the headers' <code>signature-input</code> extract the signature-input string.</li>\n<li>From the signature-input string extract the order of the Signature Base.</li>\n<li>Construct the Signature Base.</li>\n<li>From the signature-input string extract the keyid.</li>\n<li>Get the Public Key from the keyid.</li>\n<li>Use <code>openssl_verify()</code> to verify the Signature Base and the base64 decoded signature, against the Public Key using SHA256.</li>\n</ol>\n\n<p>Note, <a href=\"https://docs.joinmastodon.org/spec/security/#http-message-signatures\">Mastodon <em>only</em> uses SHA256</a>. I think it should explicitly say which algorithm it is using <a href=\"https://github.com/mastodon/mastodon/issues/29905#issuecomment-5440336919\">and have raised the issue</a>.</p>\n\n<h3 id=\"in-code-form\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#in-code-form\">In Code Form</a></h3>\n\n<p>This is how you do it in PHP. Please read this carefully as there are some hard-coded assumptions.</p>\n\n<pre><code class=\"language-php\"><?php\n\n// Validate the Digest.\n// It is the hash of the raw input string, in binary, encoded as base64.\n\n// The format is content-digest => <algorithm>=:<base64 encoded hash>:\n$digestString = $headers[\"content-digest\"];\n// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.\n$digestData = explode( separator: \"=\", string: $digestString, limit: 2 );\n\n// Hashes are in lowercase, but have a `-` in their name.\n// This is not what hash_algos() expects.\n$digestAlgorithm = str_replace( search: \"-\", replace: \"\", subject: $digestData[0] );\n\n// The hash is surrounded by `:` characters.\n$digestHash = str_replace( search: \":\", replace: \"\", subject: $digestData[1] );\n\n// Check if the hash algorithm is one known about to PHP.\n// If not, reject and record an error.\nif ( !in_array( needle:$digestAlgorithm, haystack: hash_algos() ) ) {\n return false;\n}\n\n// Manually calculate the digest based on the data sent.\n$digestCalculated = base64_encode( hash( algo: $digestAlgorithm, data: $input, binary: true ) );\n\n// Does our calculation match what was sent?\nif ( !( $digestCalculated == $digestHash ) ) {\n return false;\n}\n\n// The signature format is signature => <signature name>=:<base64 encoded hash>:\n$signatureString = $headers[\"signature\"];\n// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`.\n$signatureData = explode( separator: \"=\", string: $signatureString, limit: 2 );\n$signatureName = $signatureData[0];\n\n// The signature is surrounded by `:` characters.\n$signatureB64 = str_replace( search: \":\", replace: \"\", subject: $signatureData[1] );\n\n// The signature-input format is complicated!\n$signatureInputString = $headers[\"signature-input\"];\n\n// Get the parameters. Assume there is only one signature.\n$signatureParamsString = explode( separator: \"=\", string: $signatureInputString, limit: 2 )[1];\n\n// Get the different elements of the signature.\n$signatureInputData = explode( separator: \";\", string: $signatureInputString );\n\n// Construct the data.\n$signatureInput = [];\nforeach( $signatureInputData as $signatureInputParts ) {\n $partsData = explode( separator: \"=\", string: $signatureInputParts );\n // Strip quotes from keyid and parentheses from sig1.\n if ( \"keyid\" == $partsData[0] ) {\n $partsData[1] = str_replace( search: \"\\\"\", replace: \"\", subject: $partsData[1] );\n }\n\n if ( $signatureName == $partsData[0] ) {\n $partsData[1] = str_replace( search: [\"(\", \")\"], replace: \"\", subject: $partsData[1] );\n }\n\n $signatureInput[ $partsData[0] ] = $partsData[1] ;\n}\n\n$signatureStructure = $signatureInput[$signatureName];\n$signatureKeyID = $signatureInput[\"keyid\"];\n\n// Remove quotes.\n$signatureStructure = str_replace( search: \"\\\"\", replace: \"\", subject: $signatureStructure );\n$signatureStructureData = explode( separator: \" \", string: $signatureStructure );\n\n// https://www.rfc-editor.org/info/rfc9421/#section-2.5\n$signatureBase = \"\";\nforeach ( $signatureStructureData as $signatureStructureParts ) {\n if ( \"@method\" == $signatureStructureParts ) {\n // https://www.rfc-editor.org/info/rfc9421/#name-method\n $signatureBase .= \"\\\"@method\\\": \" . $_SERVER[\"REQUEST_METHOD\"] . \"\\n\";\n }\n if ( \"@target-uri\" == $signatureStructureParts ) {\n // https://www.rfc-editor.org/info/rfc9421/#section-2.2.2\n // Change the domain name to your own.\n $signatureBase .= \"\\\"@target-uri\\\": https://EXAMPLE.COM\" . $_SERVER[\"REQUEST_URI\"] . \"\\n\";\n }\n if ( \"content-digest\" == $signatureStructureParts ) {\n $signatureBase .= \"\\\"content-digest\\\": $digestString\\n\";\n }\n}\n\n// https://victoronsoftware.com/posts/http-message-signatures/#how-the-signature-is-created\n$signatureBase .= \"\\\"@signature-params\\\": $signatureParamsString\";\n\n// Get the signing user's public key.\n// This is usually in the form `https://example.com/user/username#main-key`\n// This is to differentiate if the user has multiple keys.\n// This may need to be a signed request. You will need to write your own getDataFromURl() function to get the sending user's key.\n$userData = getDataFromURl( $signatureKeyID );\n$publicKey = $userData[\"publicKey\"][\"publicKeyPem\"];\n\n// Verify the request\n$verified = openssl_verify(\n data: $signatureBase,\n signature: base64_decode( $signatureB64 ),\n public_key: $publicKey,\n algorithm: $digestAlgorithm\n);\n\n// Convert the result to boolean.\nif ( $verified === 1 ) {\n $verified = true;\n} elseif ( $verified === 0 ) {\n $verified = false;\n} else {\n $verified = null;\n}\n\nreturn $verified;\n</code></pre>\n\n<h2 id=\"further-reading\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#further-reading\">Further Reading</a></h2>\n\n<ul>\n<li><a href=\"https://www.rfc-editor.org/info/rfc9421/\">RFC 9421 HTTP Message Signatures</a></li>\n<li><a href=\"https://victoronsoftware.com/posts/http-message-signatures/\">Understanding HTTP message signatures: A developer's guide</a></li>\n<li><a href=\"https://www.otoroshi.io/docs/tutorials/http-message-signatures-rfc9421/\">Sign and verify HTTP messages (RFC 9421)</a></li>\n<li><a href=\"https://darutk.medium.com/verification-of-http-message-signatures-501bbdc7dfec\">Verification of HTTP Message Signatures</a></li>\n<li><a href=\"https://github.com/macgirvin/HTTP-Message-Signer\">HTTP-Message-Signer in PHP</a></li>\n</ul>\n\n<h2 id=\"thanks-to-nlnet\"><a href=\"https://shkspr.mobi/blog/2026/09/a-reasonably-practical-guide-to-validating-rfc-9421-http-signatures-for-activitypub-in-php/#thanks-to-nlnet\">Thanks to NLnet</a></h2>\n\n<p>This blog post was funded in part by the work I'm doing for my NLnet NGI0 grant. Thanks!</p>\n\n<p><a href=\"https://nlnet.nl/project/ActivityBot/\"><img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp\" alt=\"NLnet logo.\" width=\"900\" height=\"200\" class=\"aligncenter\"></a></p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74429&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "ActivityBot",
"term": "ActivityBot",
"url": "https://shkspr.mobi/blog"
},
{
"label": "ActivityPub",
"term": "ActivityPub",
"url": "https://shkspr.mobi/blog"
},
{
"label": "mastodon",
"term": "mastodon",
"url": "https://shkspr.mobi/blog"
},
{
"label": "php",
"term": "php",
"url": "https://shkspr.mobi/blog"
},
{
"label": "webdev",
"term": "webdev",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74414",
"title": "Book Review: ActivityPub by Evan Prodromou ★★★★⯪",
"description": "As part of my grant from NLnet to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text. Sometimes you just want one book which collates all the info and…",
"url": "https://shkspr.mobi/blog/2026/09/book-review-activitypub-by-evan-prodromou/",
"published": "2026-09-01T11:34:18.000Z",
"updated": "2026-08-31T18:53:48.000Z",
"content": "<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/activitypub.jpg\" alt=\"Book cover with a parrot on it.\" width=\"200\" class=\"alignleft\">\n\n<p>As part of <a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/\">my grant from NLnet</a> to improve my Fediverse bot project, I'm spending time making sure I understand all the fundamentals of ActivityPub. The problem with Internet standards is they're scattered all over the place. Abandoned forums, half-maintained wikis, mailing lists with obscure rules, and monolithic blocks of text.</p>\n\n<p>Sometimes you just want one book which collates all the info and presents it in a consistent format. This is <em>nearly</em> that book.</p>\n\n<p>Evan Prodromou has the unenviable task of making the whole ecosystem easy to understand. Thankfully he does that well. Things are logically laid out, there are comprehensive descriptions of even the most obscure parts of the spec, and it builds up nicely from the fundamentals. Oh, it's also surprisingly light-hearted.</p>\n\n<blockquote><p>This principle is so important and long-winded that web architects have given it an acronym, HATEOAS. (We often pronounce it “HATE-ee-OH-us,” which sounds like a breakfast cereal nobody wants to eat. This is one reason web architects aren’t allowed to name breakfast cereals.)</p></blockquote>\n\n<p>There's an excellent checklist for all the steps needed when building a minimal ActivityPub server.</p>\n\n<p>As with all O'Reilly books, it is a beautifully typeset ePub. Even better, it was supplied DRM-free through Kobo.</p>\n\n<p>About the only significant thing missing is details of how to verify RFC 9421 HTTP Signatures. That's understandable as they're pretty new, but a bit annoying as that's what a lot of servers are sending now. Similarly, there's a good write up of how to publish a poll, but not much about voting or publishing the results.</p>\n\n<p>The \"Far Horizons\" chapter is particularly exciting - giving a speculative overview of what AP <em>could</em> be used for. I, for one, am particularly looking forward to putting my Internet Connected Fridge on social media 😆</p>\n\n<p>Ultimately ActivityPub is a living and evolving set of standards. No book can possibly keep up with all the changes happening to it - but Evan does a brilliant job of bringing together all the moving parts and creating a coherent picture of the standard.</p>\n\n<p>Highly recommended if you're interested in understanding the fundamentals of the Fediverse!</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74414&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "ActivityPub",
"term": "ActivityPub",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Book Review",
"term": "Book Review",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74461",
"title": "Review: Ruined Theatre's A Midsummer Night's Dream ★★★★☆",
"description": "The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us? Ruined Theatre brings a brilliant cast of seasoned West End performers to strut…",
"url": "https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/",
"published": "2026-08-31T11:34:08.000Z",
"updated": "2026-08-31T09:51:55.000Z",
"content": "<p>The whole point about Shakespeare is that you can set the play on an intergalactic space station or an American high school and keep virtually the rest unchanged. What happens when you transpose Dream from a proscenium arch to a living wood? As the sun sets over the trees, what sprites will come out to entertain us?</p>\n\n<p>Ruined Theatre brings a brilliant cast of seasoned West End performers to strut their hour among the ruins of Abbey Wood. Hey, gentrification has its benefits, OK?</p>\n\n<p><a href=\"https://www.instagram.com/ruined_theatre/\"><img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/msnd.webp\" alt=\"Poster for the show, an explosion of colour.\" width=\"1024\" height=\"527\" class=\"aligncenter\"></a></p>\n\n<p>I don't know how many times I've seen \"Dream\", but I know I've never seen it performed in an actual wood during summer. Booking the tickets a few weeks ago during England's heatwave, it sounded perfect. A warm, dusky evening, accompanied by færies and asses. The British weather, of course, had other ideas.</p>\n\n<h2 id=\"the-show-must-go-on\"><a href=\"https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#the-show-must-go-on\">The Show <em>Must</em> Go On</a></h2>\n\n<p>The storm clouds were, as the bard wrote, heavy, black and, pendulous. Outside it may be raining, their makeup may be flaking, but everyone knows that Shakespeare is best played when defying the elements, right?</p>\n\n<p>Even in the rain, it was great! Theseus and Hippolyta as selfie-obsessed poseurs made for a delightful start. Recasting Athens as Lesnes was a great touch. And then we were led through the woods. Rather than traipse us from scene to scene, we settled in to a clearing - bringing our own camping chairs with us - and watched the magic unfold.</p>\n\n<p>Half the fun is in watching children and teenagers giggling at Hermia's rage and Bottom's overconfident bombast. But you can't go wrong with actors studiously ignoring the downpour and professing their (misplaced) love for each other. Honestly, who'd lie down in the mud just to make us chuckle? How many laughs can you ring out of a man with an ass's head? Lord, what fools these mortals be!</p>\n\n<p>It is a fairly straightforward production. Aside from modern dress there wasn't much updating of the text other than trimming it down. The smoke machine might have been an eerie touch on a still summer's night, billowing around us, instead the wind took it before it had a chance to settle. The incidental music worked well - especially the intertextuality of Pyramus & Thisbe playing to the Romeo+Juliet soundtrack - but the speakers were over-driven and distorted. A small crimp on an otherwise fine production.</p>\n\n<h2 id=\"reflections-in-a-dappled-pond\"><a href=\"https://shkspr.mobi/blog/2026/08/review-ruined-theatres-a-midsummer-nights-dream/#reflections-in-a-dappled-pond\">Reflections in a dappled pond</a></h2>\n\n<p>I'm fairly sure I once played Demetrius in a youth production. Or possibly Lysander. I know I got to kiss Helena. Or possibly Hermia. The mind plays funny tricks as you age. Some of the more dreary prose becomes light and airy. The laughs which felt forced come more easily. The gender politics a little more nuanced.</p>\n\n<p>You can never go back, of course. But you will always remember your first stage kiss with Hermia (or possibly Helena) with great affection. Seeing Shakespeare again and again and again in a hundred different variations just helps you realise what a master storyteller he was.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74461&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "shakespeare",
"term": "shakespeare",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Theatre Review",
"term": "Theatre Review",
"url": "https://shkspr.mobi/blog"
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},
{
"id": "https://shkspr.mobi/blog/?p=74406",
"title": "ActivityBot is the recipient of an NLnet grant!",
"description": "Back in February, I applied for NLnet's Next Generation Zero grant. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it: Reclaim the public nature of the internet Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up. I run ActivityBot - it is a single-file ActivityPub server suitable for…",
"url": "https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/",
"published": "2026-08-30T11:34:55.000Z",
"updated": "2026-08-30T10:32:47.000Z",
"content": "<p>Back in February, I applied for <a href=\"https://nlnet.nl/NGI0/\">NLnet's Next Generation Zero grant</a>. They were looking for Fediverse projects to help rewild the social media landscape. Or, as they describe it:</p>\n\n<blockquote><p>Reclaim the public nature of the internet</p>\n\n<p>Small and medium-sized R&D grants between 5.000 and 50.000 euro, with the possibility to scale up.</p></blockquote>\n\n<p>I run <a href=\"https://gitlab.com/edent/activity-bot\">ActivityBot</a> - it is a single-file ActivityPub server suitable for launching automated accounts and designed as a learning tool for those who want to understand how the protocol works. Several people have told me how useful it is, but I haven't had the time to make it better. So I decided to stick in a last-minute application to the fund.</p>\n\n<p>I really didn't know how much to apply for - or even if my project would be suitable for funding - so I cheekily asked for €10,000. After a few months of back-and-forth, I'm delighted to announce that I was successful!</p>\n\n<p>In the spirit of openness, this blog post details how the NLnet grant process worked for me and what I'll be using the money for.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/NGI-logos.webp\" alt=\"NLnet logo.\" width=\"900\" height=\"200\" class=\"aligncenter\">\n\n<h2 id=\"the-process\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#the-process\">The Process</a></h2>\n\n<p>The application was delightfully simple. Here's what it asked for, along with my answers. If you apply, please don't copy these verbatim; use your own words.</p>\n\n<blockquote>\n<ul>\n<li>Abstract : A single file server for ActivityPub. Designed for write-only bots. Allows any project to quickly and easily start publishing automated content to the Fediverse. Uses PHP, no other dependencies.\n</li><li>Experience : I am the sole developer of Single File ActivityPub - https://gitlab.com/edent/activitypub-single-php-file<br>I was formerly the UK Government's representative to the W3C and have contributed to various ActivityPub projects and specifications.\n</li><li>Amount : € 10000\n</li><li>Use : The fund will be used for development, testing, promotional activity (including conference travel).<br>I anticipate this will fund 6 months of development. I have funded all previous development.<br>\n</li><li>Comparison : Most ActivityPub services are complex. They implement a full specification and are designed for multi-user environments. Other projects allow reading and writing. ActivityBot is deliberately designed to be as simple as possible. A single file to upload, one user, publish only.<br>This will enable more projects to be able to instantly start publishing with low development cost and close to zero hosting cost.\n</li><li>Challenges : Formal spec verification and a security audit will be the main technical challenges. The ActivityBot software has been running well for over a year. The funding will allow for better compatibility and security.\n</li><li>Ecosystem : The project has mostly targeted individuals who want to run small bots. After further development, the project will engage with IoT providers, smaller publishers, open source projects who wish to publish updates, and other relevant parties.\n</li></ul>\n</blockquote>\n\n<p>I was told there was intense competition. After a couple of months, I received word that I'd made it to the 2nd round.</p>\n\n<p>What then followed was a <em>very</em> polite interrogation about my ideas, how I would develop the project, what I would use the money for, and what my AI usage policy was. They also wanted a breakdown of the main tasks - with the understanding that this would be a provisional document subject to change.</p>\n\n<p>I was on <a href=\"https://shkspr.mobi/blog/2026/07/another-ridiculous-interrail-holiday-6379km-and-13-countries-over-7-weeks/\">a train through Europe</a> when I wrote this. I don't claim it to be a brilliant document - but it got the job done!</p>\n\n<blockquote><p>1. User Research\n\n</p><p>Recruit 2 - 5 potential users. Offer an incentive (approx £20ea) to participate in a user research session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.\n\n</p><p>Total effort 3 - 4 weeks.\n\n</p><p>2. Standards Research\n\n</p><p>Participate in ActivityPub user communities and standardisation groups. Attend virtual conferences (or any local to the UK). Approx 1 day per week for 6 months.\n\n</p><p>3. Test Driven Development\n\n</p><p>Create modern test harness, write test suite, iterate design based on tests. Anticipated effort 2 days per week for approx 3 months.\n\n</p><p>4. Security Testing\n\n</p><p>Work with the community and security professionals to test the resultant code. This will use human testers and normal fuzzers - this will not use AI tools. Anticipated effort 2 days per week for approx 2 months.\n\n</p><p>5. User Acceptance Testing\n\n</p><p>Recruit 2 - 5 potential users (ideally different to the research participants). Offer an incentive (approx £20ea) to participate in a user acceptance session. Study design will take 1 - 2 days. Each interview and write up to take 1 day. Consolidation and report 2 days.\n\n</p><p>Total effort 3 - 4 weeks.\n\n</p><p>6. Updates Based on Research, Testing, and Security\n\n</p><p>While it would be lovely to anticipate getting everything right first time, the reality is that changes will need to be made based on the findings of the above. This will take up the remainder of the allocated time.</p></blockquote>\n\n<p>Again, there was a little more back and forth. But a few weeks later I was informed that I was at the final stage, pending review. And, a few weeks after that, I was told my project had been given the green light.</p>\n\n<p>I was invited to a group call where the very friendly team discussed the practicalities of the grant, what it could and couldn't fund. I also met a bunch of other people who'd also won.</p>\n\n<p>The final stage was writing a proper Memorandum of Understanding. With the help of one of the team (thanks Victoria!) I was able to turn my scrappy plan into something a bit more formal. The project tool NLnet uses made it easy to build up a plan and put € amounts by each task.</p>\n\n<p>The idea is that I will invoice against the grant whenever I have completed a task or sub-task. Obviously I don't want to leave invoicing until the end of the project, but I also need to be mindful of the foreign exchange fees charged by my bank for receiving Euro payments.</p>\n\n<h2 id=\"final-project-plan\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-project-plan\">Final Project Plan</a></h2>\n\n<p>This is the plan I submitted. It represents what I hope to accomplish and how I'll draw down on the grant. I suspect this will change as the months go on.</p>\n\n<hr>\n\n<p>ActivityBot is an Open Source project which aims to develop, maintain, and improve a minimum viable ActivityPub server in a single PHP file.</p>\n\n<p>The project is run by Terence Eden (trading as @edent); a developer residing in England.</p>\n\n<p>This project is expected to run for approximately 6 months. All of the deliverables will be openly licenced using either an OSI approved software licence or a Creative Commons licence.</p>\n\n<p>The high-level aims of the project are for ActivityBot to be:</p>\n\n<ol>\n<li><p>A fully compliant ActivityPub server, running in a single PHP file.</p></li>\n<li><p>A teaching tool to help developers understand the practical aspects of creating an ActivityPub server.</p></li>\n<li><p>A practical method of publishing automated messages to the Fediverse.</p></li>\n<li><p>A promotional tool to show how simple and easy ActivityPub development can be.</p></li>\n<li><p>A secure and usable tool written in modern PHP.</p></li>\n<li><p>Written by humans, with no AI/LLM generated code.</p></li>\n</ol>\n\n<p>In light of NLnet's non-profit status, costs assume a discounted rate of €330 per day (£280). Incidentals such as hardware, software, travel, or sundries will be charged at cost with receipts provided.</p>\n\n<h2 id=\"prepare-for-initial-release\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#prepare-for-initial-release\">Prepare for initial release</a></h2>\n\n<p>Ensure that the project is in a suitable state for initial release and future development.</p>\n\n<p>Deliverable: Updates published to GitLab.</p>\n\n<ul>\n<li><p>€495 Prepare initial release. Clarify licencing, solicit community engagement, include example usage.</p></li>\n<li><p>€495 Standards Research. Collation of standards websites. Ensure code comments refer to specific standards. Publish blog post(s) about findings for others to reference.</p></li>\n</ul>\n\n<h2 id=\"user-research\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-research\">User Research</a></h2>\n\n<p>Recruit up to 10 participants for a user-research study. Participants should represent the diversity of the Fediverse.</p>\n\n<p>Investigate what participants want from a tool like ActivityPub. The project plan may be adapted following the results of this study.</p>\n\n<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on the results will be pushed to GitLab.</p>\n\n<ul>\n<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>\n<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>\n</ul>\n\n<h2 id=\"test-driven-development\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#test-driven-development\">Test Driven Development</a></h2>\n\n<p>Create a modern test harness, write test suite, iterate design based on tests.</p>\n\n<p>Deliverable: Tests published to GitLab. Blog posts published about the process and results.</p>\n\n<ul>\n<li><p>€330 Set up test suite</p></li>\n<li><p>€330 Write tests</p></li>\n<li><p>€330 Fixes based on test results</p></li>\n</ul>\n\n<h2 id=\"security-testing\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#security-testing\">Security Testing</a></h2>\n\n<p>Working with NLnet's security offering, ensure that the project meets modern security requirements.</p>\n\n<ul>\n<li>€720 Work with security team to assess security risks and possible mitigations. Fixes based on security team feedback</li>\n</ul>\n\n<p>Deliverable: Updates published to GitLab. Blogs published about the process and results.</p>\n\n<h2 id=\"user-acceptance-testing\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#user-acceptance-testing\">User Acceptance Testing</a></h2>\n\n<p>Recruit up to 10 participants for a user-acceptance study. Participants should represent the diversity of the Fediverse.</p>\n\n<p>Investigate whether participants are able to use ActivityBot. See which aspects need improvement. The project plan may be adapted following the results of this study.</p>\n\n<p>Deliverable: Study plan and results will be published and given a Creative Commons licence. Changes based on feedback will be published to GitLab.</p>\n\n<ul>\n<li><p>€660 Study Design and recruitment of participants (blog post published as deliverable).</p></li>\n<li><p>€990 Two days of user interviews, write up and publish results as blog post.</p></li>\n</ul>\n\n<h2 id=\"conferences-and-standards-work\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#conferences-and-standards-work\">Conferences and Standards Work</a></h2>\n\n<p>Open Source participation often depends on attending conferences, either in person or virtually. Getting involved in the standardisation process ensures that future versions of ActivityPub and associated standards will be suitable for the community.</p>\n\n<p>Deliverables: Presentations material (slideware), speaking at conferences (may be published as video), conference outputs. Where possible, these will be available under a suitable Creative Commons licence.</p>\n\n<ul>\n<li><p>€700 Travel and accommodation to one EU conference</p></li>\n<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>\n<li><p>€330 Publishing blog posts about ActivityPub standards work.</p></li>\n</ul>\n\n<h2 id=\"final-release\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#final-release\">Final release</a></h2>\n\n<p>Creating a final release for this phase of the ActivityBot project. This will involve incorporating all feedback received so far, improving documentation, and publishing code.</p>\n\n<p>Deliverable: Updates published to GitLab. Blog post written. Release announcements.</p>\n\n<ul>\n<li><p>€330 Phase 1: Process and implement feedback from users</p></li>\n<li><p>€330 Phase 2: Bug fixes</p></li>\n<li><p>€330 Phase 3: Features</p></li>\n<li><p>€330 Phase 4: Bug fixes</p></li>\n<li><p>€330 Phase 5: Features</p></li>\n<li><p>€330 Phase 6: Remedial work</p></li>\n<li><p>€330 Process and implement feedback from accessibility scan</p></li>\n<li><p>€330 Final release</p></li>\n</ul>\n\n<h2 id=\"next-steps\"><a href=\"https://shkspr.mobi/blog/2026/08/activitybot-is-the-recipient-of-an-nlnet-grant/#next-steps\">Next Steps</a></h2>\n\n<p>I've already begun work on updating the code. If you'd like to get involved, or have suggestions or bug reports - please <a href=\"https://gitlab.com/edent/activity-bot\">take a look at ActivityBot on GitLab</a>.</p>\n\n<p>I'll be putting out a call for user-research participants once I've had a chance to catch my breath 😆</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74406&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "ActivityBot",
"term": "ActivityBot",
"url": "https://shkspr.mobi/blog"
},
{
"label": "ActivityPub",
"term": "ActivityPub",
"url": "https://shkspr.mobi/blog"
},
{
"label": "fediverse",
"term": "fediverse",
"url": "https://shkspr.mobi/blog"
},
{
"label": "NLnet",
"term": "NLnet",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=69787",
"title": "A simple \"copy this code\" button in JavaScript",
"description": "Next to all the code samples on this blog is a little \"copy\" button. That makes it easier to grab any of the code I've shared. The HTML and JS is delightfully simple: <button onclick=\"navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );\" title=\"Copy code\" >⧉</button> The navigator.clipboard.writeText needs a user interaction to w…",
"url": "https://shkspr.mobi/blog/2026/08/a-simple-copy-this-code-button-in-javascript/",
"published": "2026-08-29T11:34:49.000Z",
"updated": "2026-08-30T18:29:45.000Z",
"content": "<p>Next to all the code samples on this blog is a little \"copy\" button. That makes it easier to grab any of the code I've shared.</p>\n\n<p>The HTML and JS is delightfully simple:</p>\n\n<pre><code class=\"language-html\"><button\n onclick=\"navigator.clipboard.writeText(\n this.parentNode.getElementsByTagName('code')[0].textContent\n );\" \n title=\"Copy code\"\n>⧉</button>\n</code></pre>\n\n<p>The <code>navigator.clipboard.writeText</code> needs a user interaction to work - so it is tied to a click on the button.</p>\n\n<p>It takes some plaintext content. But how to get that content? My code samples look like this:</p>\n\n<pre><code class=\"language-html\"><pre itemscope itemtype=https://schema.org/SoftwareSourceCode translate=no>\n <button onclick=\"navigator.clipboard.writeText( this.parentNode.getElementsByTagName('code')[0].textContent );\">⧉</button>\n <span>\n <img alt height=32 src=html.svg width=32>\n <span itemprop=programmingLanguage> HTML</span>\n </span>\n <code itemprop=text>[…]</code>\n</pre>\n</code></pre>\n\n<p>There are various ways I could get that <code><code></code> element:</p>\n\n<ul>\n<li>Give it a unique ID (but that might clutter the code, or conflict with something else).</li>\n<li>Use <code>this.nextSibling.nextSibling</code> (but that might not work if the layout changes).</li>\n<li>Use <code>this.lastChild.textContent</code> (but, again, depends on the layout staying the same).</li>\n<li>Select based on <code>itemprop</code> (could make the code a bit longer).</li>\n<li>Complex filtering on a NodeList (urgh).</li>\n</ul>\n\n<p>None of those are particularly bad <i lang=\"la\">per se</i>, so I've chosen the method which makes most sense to me.</p>\n\n<p>You can read more about my <a href=\"https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/\">Classless Design</a>, and how I use <a href=\"https://shkspr.mobi/blog/2024/08/what-programming-language-is-in-this-code-block/\">metadata to identify programming languages</a>, including whether <a href=\"https://shkspr.mobi/blog/2026/01/should-htmls-blocks-be-translated/\">HTML's code blocks be translated</a>.</p>\n\n<p>To let people know that it has worked, I've added a little <a href=\"https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/popover\">popover</a>.</p>\n\n<p>Every piece of code has it's own <code>dialog</code> element with a unique id:</p>\n\n<pre><code class=\"language-html\"><dialog\n id=pop\n popover=hint>Copied JS to 📋</dialog>\n</code></pre>\n\n<p>No JavaScript is required to show the popover when the copy button is pressed:</p>\n\n<pre><code class=\"language-html\"><button popovertarget=pop popovertargetaction=show>\n</code></pre>\n\n<p>Closing the the popover hint doesn't require JS; clicking outside it will dismiss it. But a little scrap of JS on the button's <code>onclick</code> will make it disappear after a few seconds:</p>\n\n<pre><code class=\"language-js\">setTimeout(\n function() {\n document.getElementById(\"pop\").hidePopover();\n }, \n3000);\n</code></pre>\n\n<p>The browser's default is to place it in the middle of the screen.</p>\n\n<p>Positioning the popup so it is in proximity to the button also requires CSS - no JS.</p>\n\n<pre><code class=\"language-css\">dialog[popover] {\n inset: unset;\n position: absolute;\n position-area: top;\n padding: .5em;\n}\n</code></pre>\n\n<p>OK, that started out simple but got a bit more complex. Sorry!</p>\n\n<p><ins datetime=\"2026-08-30T18:28:40+00:00\">Update!</ins> It turns out there are some accessibility issues with this approach. See <a href=\"https://codepen.io/editor/ccwilcox/pen/01a04d8d-3691-7003-b8f6-df7439ecbd0a\">these updates by Curtis Wilcox</a>.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=69787&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "HowTo",
"term": "HowTo",
"url": "https://shkspr.mobi/blog"
},
{
"label": "HTML",
"term": "HTML",
"url": "https://shkspr.mobi/blog"
},
{
"label": "javascript",
"term": "javascript",
"url": "https://shkspr.mobi/blog"
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]
},
{
"id": "https://shkspr.mobi/blog/?p=73004",
"title": "\"iT woRKs BeTter in THe aPp!!\"",
"description": "The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation. I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar a…",
"url": "https://shkspr.mobi/blog/2026/08/it-works-better-in-the-app/",
"published": "2026-08-28T11:34:46.000Z",
"updated": "2026-08-25T07:14:14.000Z",
"content": "<p>The monkey-punchers at Google never quite seem to finish any of their apps. There's always some useful bit of work left undone, or showstopping bug which remains unfixed, a thousand jagged edges as yet unsolved by the greatest minds of their generation.</p>\n\n<p>I wanted to subscribe to an events calendar. I had a URl. I had my Google™ Pixel® phone running the latest Android© 17 with an updated calendar app. Is it possible to click on a calendar link and add it to my phone?</p>\n\n<p>No.</p>\n\n<p>Here's what <a href=\"https://support.google.com/calendar/answer/37100\">Google has to say about the matter</a>:</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/07/Google-Calendar-Help.webp\" alt=\"To subscribe to a new calendar, you must use a computer web browser. You can't subscribe to a calendar in the Google Calendar app for Android, iPhone, or iPad.\" width=\"920\" height=\"760\" class=\"alignnone size-full wp-image-73005\">\n\n<p>Really?!? I mean, fucking <em>really</em>????</p>\n\n<p>This isn't the most complex software engineering task known to humanity. Add a + button. Pop open a text entry field. Validate. Save. Done. I'm sure even the shitty Gemini model can vibe code that in a couple of months, right?</p>\n\n<p>Anyway, I opened calendar.google.com on my phone (using desktop mode), added the calendar, and it magically appeared in the app.</p>\n\n<p>This is just pathetic.</p>\n\n<p>In fairness, this isn't only a Google problem. Many companies want a permanent presence on your homescreen and think you're too thick to use your browser's bookmarks feature. Maybe they're right. Maybe an app <em>is</em> the only way to increase the engagement KPI sufficiently so Quinn in the leadership squad can hit their OKRs and get a bonus.</p>\n\n<p>So they build an app. Or, rather, they half-arse it. I've lost count of the number of times I've been told \"it's easier if you use our app\" only to be unceremoniously punted back to the web when I try to do anything outside of the app's narrow strictures.</p>\n\n<p>I was there in the early days of phone apps. I built stuff for Symbian, BlackBerry, even the bloody Palm Pilot! The central problem with apps has always been that they are hard to update. Every new bit of functionality - or even a new page - needs to be tested on a thousand devices. Once done, it takes an age to distribute to users. The only way to solve that is to have the app dynamically pull in new functionality from a remote resource.</p>\n\n<p>At which point, you've reinvented the Web browser!</p>\n\n<p>Sure, there are some things you can <em>only</em> do with an app (<a href=\"https://developer.chrome.com/blog/serial-over-bluetooth/\">although browsers are catching up</a>), and having an icon on the homescreen is useful (which is <a href=\"https://favicon.io/tutorials/favicon-sizes/\">easy for sites to add</a>), as is offline functionality (which, again, <a href=\"https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers\">is possible on the web</a>).</p>\n\n<p>Oh.</p>\n\n<p>If you want an app, fine. Do it. Just finish the job please!</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73004&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "android",
"term": "android",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Apps",
"term": "Apps",
"url": "https://shkspr.mobi/blog"
},
{
"label": "google",
"term": "google",
"url": "https://shkspr.mobi/blog"
},
{
"label": "rant",
"term": "rant",
"url": "https://shkspr.mobi/blog"
}
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},
{
"id": "https://shkspr.mobi/blog/?p=73408",
"title": "Book Review: The Infinite Sadness of Small Appliances by Glenn Dixon ★★★★☆",
"description": "This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death? It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a…",
"url": "https://shkspr.mobi/blog/2026/08/book-review-the-infinite-sadness-of-small-appliances-by-glenn-dixon/",
"published": "2026-08-27T11:34:48.000Z",
"updated": "2026-07-23T22:11:55.000Z",
"content": "<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/07/Infinite-Sadness-of-Small-Appliances-1-532x815-1.jpg\" alt=\"Book cover.\" width=\"200\" class=\"alignleft size-full wp-image-73409\">\n\n<p>This is a charming and zeitgeisty novel which has a strong start and fulfils the promise of its blurb. What if your autonomous vacuum cleaner was sentient and was very sad about your wife's death?</p>\n\n<p>It pays obvious homage to the Brave Little Toaster, 100 Acre Woods, Beauty and The Beast, and hundred other what-if-your-toys-came-to-life stories. Along the way we discover what it is like to be a transfem robo-hacker in domestic peril, why clocks are so bossy, and whether art is a cure for grief.</p>\n\n<p>The world-building is a little basic (The Algorithm™ is managing humanity's decline) but the characters are well constructed. A little derivative, it's true. Nevertheless, it is a touching tale, told well, and with a decent pace.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73408&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "Book Review",
"term": "Book Review",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Sci Fi",
"term": "Sci Fi",
"url": "https://shkspr.mobi/blog"
}
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},
{
"id": "https://shkspr.mobi/blog/?p=74230",
"title": "Gadget Review: Thermal Master P3 Macro Lens ★★★★⯪",
"description": "The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried. Whereas previous cameras are good for bird watching, or wildlife spotting, or finding leaks at home - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics. Yup! See just how hot your CPU is getting…",
"url": "https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/",
"published": "2026-08-26T11:34:52.000Z",
"updated": "2026-08-25T12:37:17.000Z",
"content": "<p>The good folks at Thermal Master have sent me their latest camera to review - and it is a bit different to all the others I've tried.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3-thermal-camera-close-up.webp\" alt=\"A small black camera with gold accents. It is held in the fingertips.\" width=\"3212\" height=\"2409\" class=\"aligncenter\">\n\n<p>Whereas previous cameras are good for <a href=\"https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/\">bird watching</a>, or <a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-t2-max-plug-in-thermal-camera/\">wildlife spotting</a>, or <a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/\">finding leaks at home</a> - the P3 has a manual macro lens and is specifically designed for getting close-up and personal with your electronics.</p>\n\n<p>Yup! See just how hot your CPU is getting 🥵</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/pi.webp\" alt=\"A thermal image of a raspberry pi. The CPU is in red while the rest of the board is green.\" width=\"1344\" height=\"1008\" class=\"aligncenter\">\n\n<p>Let's take it for a spin!</p>\n\n<h2 id=\"unboxing\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#unboxing\">Unboxing</a></h2>\n\n<p>As well as the camera (which looks <em>gorgeous</em> with its gold trim) you get a carry-case, USB-C extension cable, and a Lightning converter for older iPhones.</p>\n\n<p>The metal casing of the camera feels delightful and gives it a bit of heft. The focus wheel is reasonably stiff which makes it easier to position just right.</p>\n\n<h2 id=\"sample-photos\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#sample-photos\">Sample Photos</a></h2>\n\n<p>These are the raw images taken directly from the app. I haven't resized or altered them in any way. What you see is what you get. Here's a hot-spot on a circuit board:</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/hotspot.webp\" alt=\"A circuit rendered in grey with a bright red line on it.\" width=\"1344\" height=\"1008\" class=\"aligncenter\">\n\n<p>The natural size of the images is 1344x1008. That's obviously upscaled from the sensor, but there's a surprisingly amount of detail in there.</p>\n\n<p>Here's a small circuit board which has just booted up:</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/Circuit-long-shot.webp\" alt=\"A small circuit. Two of the chips are noticeably hotter than the rest of the board.\" width=\"1344\" height=\"1008\" class=\"aligncenter\">\n\n<p>Where the P3 shines is when you twist the manual lens all the way down to macro. You can get about 2cm away from a surface and stay in focus.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/Chip-close-up.webp\" alt=\"Close up of a small chip. It is hot, the traces are visible in the background.\" width=\"1344\" height=\"1008\" class=\"aligncenter\">\n\n<p>Obviously don't get that close to something red hot!</p>\n\n<p>Annoyingly, the images are uncompressed JPEG and weigh in around 6MB each. I've losslessly compressed these to WebP, which is about 10% of the size.</p>\n\n<h3 id=\"colours\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#colours\">Colours</a></h3>\n\n<p>There are a variety of different colour palettes to play with. Some are more useful than others. Here's a mug of hot and delicious matcha rendered in the various colours:</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/Hot-Tea-Montage.webp\" alt=\"Four photos of a mug. The colours show how hot the tea is.\" width=\"2688\" height=\"2016\" class=\"alignleft\">\n\n<p>Scrolling through the colours is a little difficult in the app (more on that later) but once you've found one you like, it stays that way for the photography session.</p>\n\n<h3 id=\"exif\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#exif\">EXIF</a></h3>\n\n<p>Geolocation is taken from the phone - there's no GPS chip in the camera. You can refuse location permission to the app and it will work just fine.</p>\n\n<p>That's just about all you get other than the time and the model name of <code>USB_IR_RS300_P2L</code> - the infrared details aren't recorded separately.</p>\n\n<h2 id=\"video\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#video\">Video</a></h2>\n\n<p>The video doesn't upsample the image, it has a resolution of 504x672 playing at 25fps. Audio is recorded from the phone's microphone and is 64kbps mono. A minute of video is around 22MB. I've recompressed this one for the web.</p>\n\n<p></p><div style=\"width: 620px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-74230-2\" width=\"620\" height=\"465\" preload=\"metadata\" controls=\"controls\"><source type=\"video/mp4\" src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4?_=2\"><a href=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4\">https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4</a></video></div><p></p>\n\n<h2 id=\"the-app\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#the-app\">The App</a></h2>\n\n<p>It is, sadly, an inevitability that good hardware is always accompanied by a substandard app. The <a href=\"https://play.google.com/store/apps/details?id=com.thermalmaster.p2telephoto\">Thermal Master Android App</a> is the only way to access the camera. It has a relatively easy to use interface with plenty of options.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/Camera-interface.webp\" alt=\"Camera interface with janky UI.\" width=\"504\" class=\"aligncenter\">\n\n<p>As you can see from the word \"brightness\" the UI is a little janky in places.</p>\n\n<p>There's a decent amount of settings to fiddle with.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/more-settings.webp\" alt=\"Settings screens with various temperature settings.\" width=\"504\" class=\"aligncenter\">\n\n<p>You can also change which elements get displayed on the final image.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/settings.webp\" alt=\"Settings to control the camera.\" width=\"504\" class=\"aligncenter\">\n\n<p>Unfortunately, it is also a bit crash-happy. Most times I used it, the app would randomly close. It takes a little while to re-open thanks to a mandatory animation. So it gets a bit annoying. Flicking through some of the options can be slow and tedious. It also doesn't respect the phone's orientation, so images may be 90⁰ off what you expect.</p>\n\n<p>The app updated the firmware on the camera, but didn't say what had changed.</p>\n\n<p>It takes photos and videos, allows you to share them, and has a bunch of options to play with - but it does have a habit of crashing just when you're about to take the perfect shot. There is also zoom available, but it is digital only - so you're just making the pixels bigger rather than getting optically closer to the object you're scanning.</p>\n\n<h2 id=\"linux-info\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#linux-info\">Linux Info</a></h2>\n\n<p>I tried plugging it in to a Linux laptop. It shows up as <code>3474:45a2 Thermal Master Technology Co., Ltd. P3</code> - but that's about it. There's no way I can find to access the thermal images.</p>\n\n<p>To be fair, this is explicitly sold as an Android and iOS device. I'm hopeful someone will be able to reverse engineer it.</p>\n\n<h2 id=\"cost-and-final-thoughts\"><a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-thermal-master-p3-macro-lens/#cost-and-final-thoughts\">Cost and Final Thoughts</a></h2>\n\n<p>Thermal cameras are expensive. This will run you about <a href=\"https://link.amazon/B0aFBVuY9\">£280 on Amazon</a> or about <a href=\"https://thermalmaster.com/en-gb/products/p3-thermal-camera-for-iphone-and-android\">£260 direct</a>. Readers of this blog can get 10% off using code <code>THERMALBF10</code></p>\n\n<p>If you run a hackspace, this is a no-brainer. The ability to see hot-spots on your circuits is immediately useful. The detail is impressive, allowing you to see exactly what's causing problems.</p>\n\n<p>If you're a hobbyist, this is definitely in the \"ask Santa if you've been good\" category. You'll find it handy on any small projects you have, or to diagnose faults with electrical equipment.</p>\n\n<p>For non-macro uses, it's also pretty good. You might be better off with a dedicated device if you want to go <a href=\"https://shkspr.mobi/blog/2026/07/gadget-review-thermal-master-dv2-infrared-birdwatching-scope/\">hunting wildlife</a> or doing <a href=\"https://shkspr.mobi/blog/2026/08/gadget-review-hikmicro-d02-thermal-camera/\">home surveys</a>.</p>\n\n<p>The only fly in the ointment is the app. While somewhat customisable, it does repeatedly crash and it isn't the easiest to use or set up. I found that pretty frustrating and have fed back the problem to the developers. I appreciate it saving high quality images - but a PNG or lossless WebP would be easier to work with than massive JPGs.</p>\n\n<p>Ultimately, this is an excellent thermal camera. It looks lush, it is customisable, the images are high quality, and the macro-lens is surprisingly useful.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74230&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [
{
"url": "https://shkspr.mobi/blog/wp-content/uploads/2026/08/p3focusvid.mp4",
"image": null,
"title": null,
"length": 3235198,
"type": "video",
"mimeType": "video/mp4"
}
],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "gadget",
"term": "gadget",
"url": "https://shkspr.mobi/blog"
},
{
"label": "infrared",
"term": "infrared",
"url": "https://shkspr.mobi/blog"
},
{
"label": "review",
"term": "review",
"url": "https://shkspr.mobi/blog"
},
{
"label": "thermal",
"term": "thermal",
"url": "https://shkspr.mobi/blog"
},
{
"label": "usb-c",
"term": "usb-c",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74380",
"title": "Theatre Review: Cats at Regent's Park Open Air Theatre ★★★★☆",
"description": "Cats is so silly! In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature. Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in…",
"url": "https://shkspr.mobi/blog/2026/08/theatre-review-cats-at-regents-park-open-air-theatre/",
"published": "2026-08-25T11:34:22.000Z",
"updated": "2026-09-01T22:02:57.000Z",
"content": "<p>Cats is so <em>silly!</em></p>\n\n<p>In the olden days, after a wild animal was slaughtered, the tribe's shaman would wear the skin and re-enact the hunt. As he became one with the beast, the people slowly understood the ways of nature.</p>\n\n<p>Cats is a similarly spiritual experience wherein we watch androgynous sylphs gyrate across the stage and believe (if only for a moment) that the human has become feline, all in service of better understanding the mysteries of our moggies.</p>\n\n<p>Does there need to be so many sequins? So much dry ice? Such a quantity of pyrotechnics?</p>\n\n<p>No, probably not. But it all adds up to a spectacular which will keep you grinning.</p>\n\n<p>The deficiencies in Cats are somewhat inherent. The scrapbook story doesn't make a lick of sense. It is more like a variety show than musical theatre. The lyrics are, at times, utterly asinine. The music soars, until someone starts playing what sounds like a genuine 1980s Casio keyboard - and all you can hear is squelch.</p>\n\n<p>But then Gary Wilmot (!!!) comes on as Gus and all is forgiven on a haze of metatextual glory.</p>\n\n<p>The choreography and dancing are exemplary. The singing occasionally gets muddled but is mostly delightful. The stage is perfect - the wind blowing through the trees and the moon gently rising only helps to accentuate the atmosphere.</p>\n\n<p>The pre-show is good. As well as a variety of food stalls, patrons are encouraged to bring their own food and drink for a picnic. There are plenty of tables and a couple of selfie points.</p>\n\n<p>The programme isn’t horrendous at £6 but still feels like it contains more advertising than content. The queues for the loos were outrageously long and the stalls weren't particularly clean.</p>\n\n<p>There's nothing to do post-show except trudge back through the park. The selfie point is still illuminated if you want to queue for that. Even the t-shirt sales stopped after the interval.</p>\n\n<p>I first saw Cats in the West End some time in the 1980s as a child and loved it. Afterwards my parents asked if I wanted to see a ballet or an opera next. \"Eurgh! No! <em>Boring!</em>\" I said. They politely informed me that I'd just seen both in one show and my juvenile mind was blown.</p>\n\n<p>A few decades later I saw Cats on Broadway - shortly before it closed, I think. The C90 cassette they used to play the music was warbling like a demented bird and the sets looked equally tired. Despite the half empty auditorium, the cast attacked the songs with vigour. I still loved it.</p>\n\n<p>And, today, I still had goosebumps. Maybe it was the unseasonable chill in the air, maybe it was the moonlight, or maybe it was the magic of Cats!</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74380&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "musical",
"term": "musical",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Theatre Review",
"term": "Theatre Review",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74330",
"title": "Why do audience members choose specific shows at the Edinburgh Fringe?",
"description": "On our recent trip to the Edinburgh Fringe, I was bemused by just how little effort performers put in to finding out why people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with some performers paying tens of thousands of pounds. The way performers recoup the costs of performing is by getting people to pay to see a show. Acts are spending huge amounts…",
"url": "https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/",
"published": "2026-08-24T11:34:45.000Z",
"updated": "2026-09-01T22:05:06.000Z",
"content": "<p>On our <a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/\">recent trip to the Edinburgh Fringe</a>, I was bemused by just how little effort performers put in to finding out <em>why</em> people had selected their show. Taking a show to the Edinburgh Fringe is ridiculously expensive with <a href=\"https://www.scotsman.com/business/edinburgh-festival-fringe-2025-the-true-cost-of-performing-at-the-worlds-largest-arts-event-laid-bare-5247134\">some performers paying tens of thousands of pounds</a>. The way performers recoup the costs of performing is by getting people to pay to see a show.</p>\n\n<p>Acts are spending huge amounts on flyers, posters, and other promotional activities. But is any of it worthwhile?</p>\n\n<p>The performer Danielle Solof has a fascinating blog post \"<a href=\"https://daniellesolof.substack.com/p/my-real-fringe-budgets-line-by-line\">My Real Fringe Budgets, Line-by-Line</a>\" which details the actual costs of her taking two solo shows to the Fringe. She meticulously details the price of everything from transport and food, to advertising and graphic design. She says:</p>\n\n<blockquote><p>I paid for outdoor ads because absolutely no one in Edinburgh knew who I was. They <em>did</em> help, but you still have to grind to get an audience in.</p></blockquote>\n\n<p>My question to her - and all performers - is how do you know what drives an audience member to see your show?</p>\n\n<p>It can't have escaped your attention that everything we do online is tracked. If you buy so much as a toothpick, the retailer knows which YouTube reviews you watched, which words you searched for, the other products you considered, and the specific adverts you clicked on.</p>\n\n<p>In Edinburgh, no one knows nothing.</p>\n\n<p>At the end of nearly every show the performer begged us to leave a review on the Fringe website and to tell our friends. In absolutely <em>none</em> of the shows did the performer ask why we were there, how we found out about the show, which poster or leaflet attracted us, or whether we followed them on social media.</p>\n\n<p>All that money spent on posters and no one knows if they work. As the old saying goes \"<a href=\"https://quoteinvestigator.com/2022/04/11/advertising/\">Half the money I spend on advertising is wasted, and the trouble is I don’t know which half.</a>\".</p>\n\n<p>So, in an attempt to bring a <em>little</em> data to proceedings, here are how we chose the 26 shows we saw. I don't claim this is representative of everyone, but I think it might be illustrative. In rough order of importance were:</p>\n\n<h2 id=\"proximity\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#proximity\">Proximity</a></h2>\n\n<p>The EdFringe app has a \"nearby now\" feature. Click on it and you get a list of shows starting soon which are only staggering distance away.</p>\n\n<p>I cannot stress enough how much of a motivator that was. When you've spent all day traipsing, the last thing you want to do is <em>another</em> 20 minute walk uphill to see a provocative new piece of challenging theatre told through finger puppets.</p>\n\n<p>About 20% of the shows we saw were via that feature.</p>\n\n<p>Roughly another 40% were because the show was close to something else we really wanted to see. We knew that we wanted to see show X, so we looked for shows which weren't too far away from that venue. Yes, Edinburgh is a compact city with decent public transport, but it is much easier to walk round the corner or stay to have a drink in the venue's bar.</p>\n\n<p>You can <em>really</em> want to see a show, but if it is a 20 minute walk between venues and it starts 15 minutes after your last show ends, you'll skip it. I'd say that location was the key driver in most of our choices.</p>\n\n<p>I guess my top tip to any performer would be to be as near as physically possible to a bigger act!</p>\n\n<h2 id=\"friends\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#friends\">Friends</a></h2>\n\n<p>A quarter of the shows we went to were because either a friend-of-a-friend was performing, or a friend booked tickets and asked if we wanted to tag along.</p>\n\n<p>You are morally obliged to go to your friends' shows. Similarly, if a mate says \"Oh, my friend has a show on this year\", you have to make the effort to go.</p>\n\n<p>Perhaps it is a bit blasé to say that word-of-mouth works, but it's a cliché becausé it is trué.</p>\n\n<h2 id=\"flyers-and-leaflets\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#flyers-and-leaflets\">Flyers and Leaflets</a></h2>\n\n<p>We collected approximately 5,374 different promotional leaflets during our week there. Most of the time we were handed a leaflet by someone paid to hand out leaflets. They were either wordlessly stuffed into our hands, or delivered with a monotone \"wanna see improv comdy?\" Bleh.</p>\n\n<p>A few actually spoke to us about the show when we asked questions, which was a deciding factor in seeing a couple of performances.</p>\n\n<p>The best flyerers were, undoubtedly, the performers themselves. Kat Ronson in her <a href=\"https://shkspr.mobi/blog/2026/08/edinburgh-fringe-kat-ronson-millennial-girl/\">Millennial Girl</a> guise drawled at us \"You look thin and pretty. You're allowed to come to my show.\" Instant sale!</p>\n\n<p>Similarly, one rather famous comedian walked up to us and said \"You look like theatre people!\" and proceeded to pitch their show - which was a delightful encounter and would have sold us a ticket if we weren't leaving that day.</p>\n\n<p>Some flyers had a QR code or URl on them so we could watch a trailer of the show. We didn't watch any of them. Perhaps we should have?</p>\n\n<h2 id=\"posters\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#posters\">Posters</a></h2>\n\n<p>Surprisingly effective at drawing the eye! The ones which were just a photo of the comedian looking a bit \"whacky\" were dull. The ones of performers in their most seductive poses were a little naff. The ones which were just a close up of someone's face only really work if that person is incredibly famous, otherwise you're just left thinking \"who?\"</p>\n\n<p>But a few posters made us stop and immediately search for the show. Graphic design is a professional skill and one worth investing in.</p>\n\n<p>Some posters were everywhere. I took an instant (and uncharitable) dislike to one poster featuring a smug-looking twat and I swear he followed me around town. Some posters only appeared near the performance venue.</p>\n\n<p>Incidentally, there were a couple of posters which had clearly just been fed into an AI generator. Lazy and off-putting.</p>\n\n<h2 id=\"reviews\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#reviews\">Reviews</a></h2>\n\n<p>The Fringe doesn't allow weighted star reviews - so you can't immediately see if the consensus is that the show is a hit or a miss. Several of the shows we didn't enjoy got excellent reviews (from morons) and some of the shows we loved were panned (presumably by the same morons).</p>\n\n<p>In truth, I don't think the reviews influenced our decision to see anything.</p>\n\n<h2 id=\"what-stopped-us-going-to-shows\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#what-stopped-us-going-to-shows\">What <em>Stopped</em> Us Going To Shows</a></h2>\n\n<p>For every action there is an equal and opposite reaction. I think it is important for performers to know what stopped someone clicking the \"buy\" button for their show.</p>\n\n<h3 id=\"ticket-cost-value-for-money\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#ticket-cost-value-for-money\">Ticket Cost / Value For Money</a></h3>\n\n<p>Mondays and Tuesdays saw lots of shows doing a 2-for-1 promotion. I didn't mind spending £30 for two of us to take a risk on something. Come Wednesday, I wasn't prepared to pay £60 for a 45 minute show.</p>\n\n<p>I know \"surge pricing\" gets a bad rap, but <a href=\"https://shkspr.mobi/blog/2024/09/why-does-no-one-discuss-negative-dynamic-pricing/\">dynamic pricing of underselling shows</a> might help. If you've only sold four seats for today, perhaps drop the price? I don't know if the Fringe software supports that - but it seems obvious to me that having 10 people paying a fiver is better than four people paying a tenner.</p>\n\n<h3 id=\"crap-signal-long-queues\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#crap-signal-long-queues\">Crap Signal / Long Queues</a></h3>\n\n<p>We tried to get in to a circus show. My phone didn't have enough signal for the app to work and the nearest box office had a massive queue. So we bailed.</p>\n\n<p>If the venue had WiFi (not a given, weirdly) it would have gotten them an extra sale. If the ticket staff could take contactless (lots of performers did) we'd have happily paid.</p>\n\n<p>You have to make it easy for people to give you money.</p>\n\n<h3 id=\"not-enough-time\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#not-enough-time\">Not Enough Time</a></h3>\n\n<p>This is completely out of the performers' control. We had 6 days and saw about 4 shows per day. We could have seen more, but we needed to eat, explore, and sleep.</p>\n\n<p>Speaking of which, there were several midnight performances which looked excellent - but I also needed to get up the next day to see more shows. Sleep won!</p>\n\n<h3 id=\"too-famous\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#too-famous\">Too Famous</a></h3>\n\n<p>I'd love to see that guy who's on the telly. But I can watch him on the telly. That show looks like a massive success, so I'm sure it'll tour round London soon.</p>\n\n<h3 id=\"sell-outs\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#sell-outs\">Sell Outs</a></h3>\n\n<p>A few shows sold out before we could get tickets. Good for them! If that was your show, you probably don't need this blog post.</p>\n\n<h2 id=\"better-art-through-commerce\"><a href=\"https://shkspr.mobi/blog/2026/08/why-do-audience-members-choose-specific-shows-at-the-edinburgh-fringe/#better-art-through-commerce\">Better Art Through Commerce</a></h2>\n\n<p>Art should be driven by passion.</p>\n\n<p>But every performer I know listens back to their shows to see what works and what didn't. If a joke falls flat, it's cut. If a riff gets a big laugh, it's incorporated. That's the essence of data driven decision making.</p>\n\n<p>I wish every performer at the Fringe had a sell out audience and were able to recoup their costs. But that is never going to happen unless they spend time understanding what gets bums on seats.</p>\n\n<p>So here are a few scattered thoughts on how they could do that.</p>\n\n<ul>\n<li>QR code at the end of the show leading to a survey. Literally ask people \"what made you choose this performance?\"</li>\n<li>In the queue before the show, or as people are taking their seats, hand out a paper questionnaire.</li>\n<li>Talk to the audience after the show. See if you can gain any insights about what made them attend.</li>\n<li>As people are coming in, have a poster asking people to tick a box based on how they heard about the show.</li>\n<li>Give each leaflet a unique code (or a code per person handing them out). Ask people to bring the leaflet with them so you can see which area/person/leaflet was most effective.</li>\n<li>Each poster can have a unique QR code on it. Track whether the one by the station led to more ticket sales than the one in the underpass. Did the one in the gents toilets get <em>any</em> scans at all?</li>\n</ul>\n\n<p>Of course, all of the above rely on talking to people who made the choice to see you. This is classic <a href=\"https://en.wikipedia.org/wiki/Survivorship_bias\">Survivorship Bias</a>. Sure, it'll help you work out what was <em>successful</em>, but you won't know why people looked at your show and chose something else. That said, it is <em>hard</em>. How do you find people who <i lang=\"la\">ipso facto</i> aren't at your show?</p>\n\n<ul>\n<li>That could be as simple as asking people what they dislike about the leaflet when you hand it out.</li>\n<li>Each poster or leaflet can have a unique QR code on it. Which ones cause people to scan, but then abandon the idea of buying a ticket?</li>\n<li>Speak to people who came to the venue for a show other than yours. They obviously like the location, so non-confrontationally ask them why they didn't pick you?</li>\n</ul>\n\n<p>Some of these are easier than others. By themselves, they might give you a slightly misleading view of the data. But surely anything is better than looking at a half empty venue and wondering if those huge advertising costs did any good at all.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74330&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "data",
"term": "data",
"url": "https://shkspr.mobi/blog"
},
{
"label": "EdFringe",
"term": "EdFringe",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=63847",
"title": "Death to px, long live ch!",
"description": "Pixels are a lie. Even if you think you're drawing something with \"pixel perfect\" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares. In CSS, pixels are a double lie: Note that 1px doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, 1cm in CSS often doesn't correspond to one hundredth of SI…",
"url": "https://shkspr.mobi/blog/2026/08/death-to-px-long-live-ch/",
"published": "2026-08-23T11:34:52.000Z",
"updated": "2026-08-23T12:45:06.000Z",
"content": "<p>Pixels are a lie. Even if you think you're drawing something with \"<a href=\"https://shkspr.mobi/blog/2018/11/the-myth-of-the-pixel-perfect-grid/\">pixel perfect</a>\" accuracy, your monitor is lying to you. There is no grid of platonically perfect squares.</p>\n\n<p>In CSS, <a href=\"https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics/Values_and_units#lengths\">pixels are a double lie</a>:</p>\n\n<blockquote><p>Note that <code>1px</code> doesn't necessarily equal one physical device pixel. On HD displays, it may span multiple physical pixels. Similarly, <code>1cm</code> in CSS often doesn't correspond to one hundredth of SI meter. On a large TV screen, it typically is longer than that. The lengths are perceptual: <code>16px</code> looks roughly the same on a phone, laptop, or TV screen at typical viewing distance.</p></blockquote>\n\n<p>This blog is primarily text based. I want the <a href=\"https://journals.uc.edu/index.php/vl/article/view/5765/4629\">width of the text to be readable</a> for the average human. So, rather than setting the main width to be a percentage of the screen, I set it based on character width using the <code>ch</code> unit - which <a href=\"https://meyerweb.com/eric/thoughts/2018/06/28/what-is-the-css-ch-unit/\">isn't exactly a character</a> but good enough for my purposes:</p>\n\n<pre><code class=\"language-css\">--width-content: min(75ch, 100%);\n\nmain {\n max-width: var(--width-content);\n}\n</code></pre>\n\n<p>When it comes to padding and margins, the same is true. If I want a gap around an element, I want that gap to be in proportion to the text inside it.</p>\n\n<p>For widths, it makes sense to re-use the <code>ch</code> unit. I want the gap to be in proportion to the text.</p>\n\n<p>But for <em>height</em>, perhaps it doesn't make sense to express vertical distance on character width? In which case <a href=\"https://www.w3.org/Style/Examples/007/units.en.html\">the <code>ex</code> unit can be used</a>. It is the size of a typical lower-case letter.</p>\n\n<p>Just like my idea to <a href=\"https://shkspr.mobi/blog/2025/09/class-warfare-can-i-eliminate-css-classes-from-my-html/\">eliminate CSS classes from my HTML</a>, it's possible to go too far with this. I haven't changed <em>every</em> reference from px to ch, I'm just experimenting to see if it works.</p>\n\n<p>There's nothing wrong, immoral, or evil about using px - or any other measure unit. Using ch and ex fit with my particular proclivities.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=63847&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "css",
"term": "css",
"url": "https://shkspr.mobi/blog"
},
{
"label": "design",
"term": "design",
"url": "https://shkspr.mobi/blog"
},
{
"label": "HTML",
"term": "HTML",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=72903",
"title": "Book Review: An Immense World - How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong ★★★☆☆",
"description": "This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision. This isn't a game of Top Trumps where all the animals are ranked by power.…",
"url": "https://shkspr.mobi/blog/2026/08/book-review-an-immense-world-how-animal-senses-reveal-the-hidden-realms-around-us-by-ed-yong/",
"published": "2026-08-21T11:34:36.000Z",
"updated": "2026-07-29T09:03:25.000Z",
"content": "<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/07/9781473572737-jacket-large.webp\" alt=\"Book cover featuring various animals.\" width=\"200\" class=\"alignleft size-full wp-image-72904\">\n\n<p>This is a detailed examination of the various senses possessed by animals. Some will be intimately familiar to you - like sight and sound - whereas some will seem strange and uncanny - like magnetic detection and electro-sensing. Some straddle an almost understandable space like echolocation or tetra-chromatic vision.</p>\n\n<p>This isn't a game of Top Trumps where all the animals are ranked by power. Instead there's a gentle and passionate exploration of what these senses <em>might</em> mean to their owners. It is refreshingly candid about what we don't know, while always trying to convey a sense of wonder about the inherent <a href=\"https://en.wikipedia.org/wiki/Umwelt\"><i lang=\"de\">Umwelt</i></a> experienced by the animal.</p>\n\n<p>But goodness me is it long. It seems that every time the editor told the author to cut out a paragraph, he stuck it in a footnote instead. The text is well referenced, but so are the footnotes, which means occasionally encountering sentences formatted like this:</p>\n\n<blockquote><p>Despite several frustrating false leads, nobody’s ever found them.<sup>fn11,36,37,38,39</sup></p></blockquote>\n\n<p>Speaking of which, the general formatting of the eBook is poor. The CSS contains all sorts of weird stuff which I needed to turn off, and is full of comments which probably should have been stripped before the book was distributed.</p>\n\n<p>Science publishers still haven't grasped that eBooks don't need to relegate glossy images to the back of the book - they can go inline with the text!</p>\n\n<p>This is a funny, heartfelt, and (perhaps overly) thorough book. It will gleefully send you down rabbit holes - even if you're ill-equipped to see in the dark and sense the bugs around you.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=72903&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "Book Review",
"term": "Book Review",
"url": "https://shkspr.mobi/blog"
},
{
"label": "science",
"term": "science",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=73594",
"title": "Asymmetric Agents",
"description": "One of the promises of the AI-filled future is that we'll all have highly capable autonomous servants \"agents\" to work for us. Even back in the 1990s, it was a common trope in future-gazing to insist that a person's personal slave agent would negotiate on their behalf. Ask your meek digital pal agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, …",
"url": "https://shkspr.mobi/blog/2026/08/asymmetric-agents/",
"published": "2026-08-19T11:34:52.000Z",
"updated": "2026-08-20T06:17:00.000Z",
"content": "<p>One of the promises of the AI-filled future is that we'll all have highly capable autonomous <del>servants</del> \"agents\" to work for us.</p>\n\n<p>Even <a href=\"https://shkspr.mobi/blog/2026/02/how-close-are-we-to-a-vision-for-2010/\">back in the 1990s</a>, it was a common trope in future-gazing to insist that a person's personal <del>slave</del> agent would negotiate on their behalf. Ask your <del>meek digital pal</del> agent to find you a restuarant in town, tonight, for a hot date, catering to your dietary preferences, and within your budget. The little <del>butler</del> agent scurries off and, without your intervention, finds the <em>perfect</em> place, negotiates with the restaurant's <del>house boy</del> agent and books you a slap up meal.</p>\n\n<p>Marvellous! You can tell your <del>manservant</del> agent to buy you clothes, reserve a flight, do the grocery shopping, or buy your wife flowers without having to lift a finger.</p>\n\n<p>But, of course, there's a fly in the ointment. Not all <del>valets</del> agents are created equally. You're sending your Raspberry Pi powered <del>peon</del> agent against the full might of Amazon's bazillion datacentres.</p>\n\n<p>Can a low-complexity <del>serf</del> agent be bullied, outwitted, and manipulated by a more capable <del>henchman</del> agent? It seems obvious to me that the answer is yes. Humans have a set of cognitive biases which render us susceptible to advertising tricks. AI may have <a href=\"https://cacm.acm.org/research/rolling-in-the-deep-of-cognitive-and-ai-biases/\"><em>different</em> biases</a> but will still be vulnerable to <a href=\"https://shkspr.mobi/blog/2017/03/how-to-hypnotise-an-artificial-intelligence/\">hypnosis</a> and hacking.</p>\n\n<p>Perhaps having my <del>secretary</del> agent negotiate with your <del>PA</del> agent to find a suitable meeting time for our Q2 KPI Deep Dive doesn't carry this sort of risk. But I'm sure that <del>scumbags</del> advertisers everywhere will be salivating at the thought of waylaying my innocent <del>footman</del> agent on its way to market.</p>\n\n<p>A future where we delegate responsibility to <del>stochastic imbeciles</del> agents is one where we accept that we have no control over their susceptibility to more powerful and malevolent <del>thugs</del> agents.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=73594&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "agentic",
"term": "agentic",
"url": "https://shkspr.mobi/blog"
},
{
"label": "AI",
"term": "AI",
"url": "https://shkspr.mobi/blog"
},
{
"label": "future",
"term": "future",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74161",
"title": "And then the men with guns tell you to do it anyway",
"description": "In early February 2011 Egypt was in the middle of a political revolution. One morning, everyone's phones suddenly pinged with an alert. The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt. A series of messages arrived all ostensibly from the network provider Vodafone. All pro-regime and all with the…",
"url": "https://shkspr.mobi/blog/2026/08/and-then-the-men-with-guns-tell-you-to-do-it-anyway/",
"published": "2026-08-17T11:34:24.000Z",
"updated": "2026-08-17T11:31:25.000Z",
"content": "<p>In early February 2011 <a href=\"https://www.aljazeera.com/news/2023/1/25/what-happened-during-egypts-january-25-revolution\">Egypt was in the middle of a political revolution</a>. One morning, everyone's phones suddenly pinged with an alert.</p>\n\n<blockquote><p>The Armed Forces asks Egypt's honest and loyal men to confront the traitors and criminals and protect our people and honour and our precious Egypt.</p></blockquote>\n\n<p>A <a href=\"https://www.flickr.com/photos/59098813@N06/5411904816/in/photostream/\">series of messages arrived</a> all ostensibly from the network provider Vodafone. All pro-regime and all with the undercurrent of violence.</p>\n\n<p>Why did Vodafone send these messages? Earlier in the week, <a href=\"https://www.hrw.org/news/2011/01/28/egypt-nationwide-internet-blackout-endangers-rights\">all Internet access was cut off</a> now phones were blasting propaganda to the masses.</p>\n\n<p>After the network went down, Vodafone issued a statement saying:</p>\n\n<blockquote><p>It has been clear to us that there were no legal or practical options open to Vodafone, or any of the mobile operators in Egypt, but to comply with the demands of the authorities.</p></blockquote>\n\n<p>Do you have to follow orders? Do you have to obey the law even when it is unjust? Should multinational corporations instruct local executives to be loyal to their parent company or the rulers of the country they live in?</p>\n\n<p>After the messages came in - including promises that \"<a href=\"https://www.theguardian.com/news/blog/2011/feb/03/egypt-protests-live-updates#block-19\">The Armed Forces cares for your safety and well being and will not resort to using force against this great nation</a>\" - Vodafone Global, safely ensconced in the UK, put out another statement:</p>\n\n<blockquote><p>Under the emergency powers provisions of the Telecoms Act, the Egyptian authorities can instruct the mobile networks of Mobinil, Etisalat and Vodafone to send messages to the people of Egypt. They have used this since the start of the protests. These messages are not scripted by any of the mobile network operators and we do not have the ability to respond to the authorities on their content.</p>\n\n<p>Vodafone Group has protested to the authorities that the current situation regarding these messages is unacceptable. We have made clear that all messages should be transparent and clearly attributable to the originator.</p>\n\n<p><a href=\"https://web.archive.org/web/20110307151856/http://www.vodafone.com/content/index/press/press_statements/statement_on_egypt.html\">Statements - Vodafone Egypt</a></p></blockquote>\n\n<p>A few years later I was at a networking event chatting to a guy. We'd both previously worked for Vodafone. Me in the UK, he in Egypt. I asked him about the incident - he talked about how they built the SMS infrastructure, what they did to secure it, how they prevented spam, and how one day armed men arrived.</p>\n\n<p>I suspect most of us have seen a movie where some flunky in an office refuses the baddies demands to open the safe, and then gets shot in the head. Perhaps you think that's a noble death? He lived with honour and refused to yield! But, in every movie I've seen, the guy's subordinate opens the safe anyway and gets to live.</p>\n\n<p>But we're technologists, right? We can build fail safes and cryptographic proofs and <a href=\"https://knowyourmeme.com/memes/i-would-simply\">simply build infrastructure that can't be abused</a>.</p>\n\n<p>And then the men with guns come and tell you what to do.</p>\n\n<p>I've written before about <a href=\"https://shkspr.mobi/blog/2013/11/civic-hygiene/\">Civic Hygiene</a> - it's the idea that we should be mindful of the ways that our technologies could be misused. The term was coined back in 2010 by the technologist Bruice Schneier</p>\n\n<blockquote><p><a href=\"https://www.schneier.com/essays/archives/2010/01/us_enables_chinese_h.html\">It's bad civic hygiene to build technologies that could someday be used to facilitate a police state.</a></p></blockquote>\n\n<p>But what do we mean by that?</p>\n\n<p>We don't want backdoors in security products - lest hackers break in or evil governments get elected. But we want a way to access our beloved ones' data after they die. It's important that we know that photos haven't been manipulated by propagandists and saboteurs. But we want to send funny memes about that politician we don't like. We don't want police stalking ex girlfriends' cars - but we want dangerous drivers prosecuted.</p>\n\n<p>We want to be alerted about imminent threats, but don't want Governments to use that power for ill.</p>\n\n<p>Way back in the early 2020s, I had a minor role in the UK Government's adoption of <a href=\"https://github.com/co-cddo/open-standards/issues/73\">Common Alerting Protocol</a> the technology which powers cell-broadcast emergency alerts.</p>\n\n<p>Even back then, one of the discussions was around whether the utility of being able to send an unavoidable push notification was worth the risk that someone would send an inappropriate message. Fresh in everyone's minds was the <a href=\"https://www.bbc.co.uk/news/world-us-canada-42680070\">false alarm saying missiles were heading to Hawaii</a>.</p>\n\n<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/2018_Hawaii_missile_alert_cropped.jpeg\" alt=\"Emergency alert. BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.\" width=\"768\" height=\"343\" class=\"aligncenter size-full wp-image-74163\">\n\n<p>Too many safeguards means that a genuine alert doesn't get sent in time. Too few safeguards and you can blame \"<a href=\"https://shkspr.mobi/blog/2026/08/book-review-the-field-guide-to-understanding-human-error-by-sidney-dekker/\">Human Error</a>\" for any mistakes.</p>\n\n<p>I don't know which safeguards are in place for the UK's system - <a href=\"https://www.ofcom.org.uk/siteassets/resources/documents/about-ofcom/foi/2024/march/emergency-broadcasting?v=331069\">and most details are exempt from Freedom of Information requests</a>. But it is both easy and fun to speculate on how such a system might be designed.</p>\n\n<p>The Government generates an alert. It specifies where and when the alert should be sent. It sends that message to the network operators via a secure and private channel. Perhaps they also do some out-of-band verification like having the network operator call a pre-determined phone number to check the message's validity.</p>\n\n<p>At which point, the operator can choose to send the message or not.</p>\n\n<p>Or can they?</p>\n\n<p>In August 2026, the UK government instructed network operators to send this message:</p>\n\n<p><a href=\"https://www.gov.uk/alerts/14-aug-2026-2\"><img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/08/fire-alert.webp\" alt=\"Alert about fire risk in the UK.\" title=\"Screenshot courtesy of Skylar MacDonald\" width=\"1024\" height=\"851\" class=\"aligncenter size-full wp-image-74164\"></a></p>\n\n<p>Did the networks <em>have</em> to send that message? If they thought it wasn't serious enough, could they have refused? As far as I can tell, the law only talks about the fact that operators can disregard \"spam\" laws in order to send a mass message:</p>\n\n<blockquote><p>A relevant public communications provider (P) may, for the purpose of providing an emergency alert service, disregard the restrictions on the processing of data relating to users or subscribers set out in paragraph (2) if the conditions set out in paragraph (3) are met.</p>\n\n<p>[…]</p>\n\n<p>(3) The conditions are—</p>\n\n<p>(a)P is notified by a relevant public authority that—</p>\n\n<p>(i)an emergency within the meaning of section 1(1) of the Civil Contingencies Act 2004 has occurred, is occurring or is about to occur;</p>\n\n<p><a href=\"https://www.legislation.gov.uk/uksi/2015/355/pdfs/uksi_20150355_en.pdf\">Statutory Instrument 2015 No. 355</a></p></blockquote>\n\n<p>I'm no expert, but I can't see anything in <a href=\"https://www.ofcom.org.uk/siteassets/resources/documents/manage-your-licence/mobile-wireless-and-broadband/cellular/licences/cellular-licence-vodafone-0249664.pdf?v=368347\">the spectrum licence</a> nor in the <a href=\"https://www.legislation.gov.uk/ukpga/2006/36/contents\">Wireless Telegraphy Act</a> which <em>compels</em> operators to process these messages.</p>\n\n<p>The usual British way is to ask people to play nicely and threaten them with regulation if they don't.</p>\n\n<p>Could the networks have refused to send the message about wildfires - or indeed any other message? If your least favourite politician gets their hands on the emergency alert system and tries to abuse it, would you want the networks to stand up to them?</p>\n\n<p>What if the network refuses to send the message because they're worried alerting people about a hurricane will lower the company's profits?</p>\n\n<p>What if armed thugs are sent in and the choice is send the message or die?</p>\n\n<p>I don't know what the answer is here. I think most people agree that it is broadly sensible to have a way to alert the population of emergencies. There's no mass media any more, we're not all listening to a single radio channel, or reading newspapers, or even on the same social media platforms. Sometimes there are emergencies and the Government has a duty to alert people to them.</p>\n\n<p>How would you design a system that simultaneously achieved all these goals:</p>\n\n<ul>\n<li>Rapid sending of messages</li>\n<li>Careful checking of the content of messages</li>\n<li>Ability to quickly target a specific geographic area</li>\n<li>Inability to mistakenly send a test message</li>\n<li>Requiring strong proof that the message is authentic before sending</li>\n<li>Resilient enough to work after significant damage to infrastructure</li>\n<li>That networks have the ability to vet and ignore</li>\n<li>That networks are compelled to send</li>\n<li>Which can only be used for good</li>\n<li>And cannot be used for evil.</li>\n</ul>\n\n<p>In truth, <a href=\"https://bsky.app/profile/edent.tel/post/3mt2s2puhuk2x\">having experienced fire-starters</a>, I'm not bothered about the contents of this latest message from the UK Government. Given the overstretched fire service and the imminent threat across most of the country, my personal opinion is that it is proportionate.</p>\n\n<p>But it is easy to see why some people feel this might open the gateway to messages which, at best, are irrelevant and, at worst, are similar to the insidious propaganda which appeared on the phones of Egyptians:</p>\n\n<blockquote><p>To every mother-father-sister-brother, to every honest citizen. Preserve this country as the nation is forever.</p></blockquote>\n\n<p>Perhaps you can think of a way to design an alerting system which cannot be abused - but I can't.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74161&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "politics",
"term": "politics",
"url": "https://shkspr.mobi/blog"
},
{
"label": "technology",
"term": "technology",
"url": "https://shkspr.mobi/blog"
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]
},
{
"id": "https://shkspr.mobi/blog/?p=74021",
"title": "Thoughts on visiting the Edinburgh Fringe as a newbie",
"description": "This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer. P…",
"url": "https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/",
"published": "2026-08-16T11:34:21.000Z",
"updated": "2026-08-16T09:29:11.000Z",
"content": "<p>This was my first ever time at The Fringe™. Here are some scattered thoughts looking at the good, the bad, and the annoying aspects of this madly extravagant exhibition of talent. We saw 23 shows together, and one separate show each. There were more hits than misses, but the frustration of wasting your time on a bad show is rather heavy when there are literally hundreds of other shows on offer.</p>\n\n<h2 id=\"price\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#price\">Price</a></h2>\n\n<p>Everything is too expensive. We found student accommodation which was a \"mere\" £220 per night. I guess that wasn't <em>too</em> exorbitant considering the gouging going on elsewhere - and it did come with a decent breakfast. It was about a 20 minute walk from the Royal Mile, with several performance venues on the way.</p>\n\n<p>The 46 tickets we bought cost us £550 in total - which included a few donations at Free Fringe shows. So an average ticket of £12, which isn't too bad, I guess. You can certainly do things cheaper by only going to free shows and running away when they ask you to pay - but that's a dick move.</p>\n\n<p>£20 for a single hour of stand-up feels like kind of a rip off at times - especially with the mandatory £1.50 booking fee for every ticket. Some shows are a bit cheaper, and Monday/Tuesday has 2-for-1 offers. But it's easy for a couple to spend well over a hundred quid per day seeing 3 or 4 shows.</p>\n\n<p>Festival food and drink prices are inflated - but there's no shortage of supermarkets if you want a meal deal. Restaurants were usual city centre prices. The bars at festival venues were fully taking advantage of their captive audience, but the pubs aren't much cheaper.</p>\n\n<h2 id=\"the-app\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#the-app\">The App</a></h2>\n\n<p>In theory, the app / website is good. In reality they're both a bit frustrating to use. Every time I ticked the box saying \"remember my credit card details\" and every time it forgot them. Both app and website frequently timed out, failed to add tickets to baskets, and were a bit shonky. The <em>one</em> thing this needs to do is reliably take my money and give it to performers - but it felt like a battle every time.</p>\n\n<p>We missed one show because we couldn't buy a ticket in the app despite being in the queue. The door staff didn't have the ability to sell us a ticket (although some venues can) and directed us to a box office which was dealing with a bunch of people who were bemused that they couldn't pay in dollars.</p>\n\n<p>Inexplicably, the app doesn't have the ability to see show reviews, even though they're present on the website.</p>\n\n<p>There's a good \"Nearby Now\" feature which is handy when you're exhausted and don't want to trek far. By contrast, there's no easy way to see what's on near the next venue you're going to.</p>\n\n<p>Searching for shows often returns events which are cancelled or sold out.</p>\n\n<p>I wish it were possible to see which shows had undersold and were starting soon. I loved taking a punt on an unknown act who only had half-a-dozen people in the room. Sadly there's no way to grab last-minute deals.</p>\n\n<p>This isn't helped by the total collapse of mobile signal in Edinburgh centre. I tried with a variety of SIMs but frequently only got a trickle of data.</p>\n\n<h2 id=\"what-to-see\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#what-to-see\">What To See</a></h2>\n\n<p>The <abbr title=\"Fear Of Missing Out\">FOMO</abbr> is real! Every show's poster makes it look amazing. The earnest performers desperately handing out leaflets for their own shows are <em>so</em> enthusiastic. Everyone you speak to in a queue has a \"must see\" which is probably sold out.</p>\n\n<p>We mostly avoided seeing big names. They'll be on telly soon enough or tour down in London. I don't think that act who was big in the 1990s needs my coin as much as some up-and-comer.</p>\n\n<p>You could easily fill a week seeing nothing but Shakespeare in a variety of styles. Or just watch middle-aged white guys have mental breakdowns on stage because they're on their 3rd divorce. Or, as it turns out, fill your boots with Heated Rivalry shows.</p>\n\n<p>We did the tasting menu and had a little bit of everything. It was mostly pretty good with only a few duds.</p>\n\n<h2 id=\"reviews\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#reviews\">Reviews</a></h2>\n\n<p>Even the worst show we saw had a couple of people who declared it the funniest thing ever five stars lol. You can't account for someone else's taste.</p>\n\n<p>I enjoyed <a href=\"https://shkspr.mobi/blog/tag/EdFringe\">writing my reviews</a> - and I hope they were useful to others - but you're mostly on your own when it comes to what's good. I suppose if you wait until later in the festival there will be more of a consensus about what to see.</p>\n\n<p>My philosophy is to take a punt on basically anything that doesn't look too abhorrent. Even if it is shit, there's be something else along in a minute which will be better.</p>\n\n<h2 id=\"distance\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#distance\">Distance</a></h2>\n\n<p>You'll get your 10k steps in before lunchtime - Edinburgh is a delightfully walkable city. With a bit of planning you can walk a straight line from show-to-show. We didn't plan and traipsed back and forth like the little lost tourists we were.</p>\n\n<p>Venues are mostly well sign-posted. Again, the app is a bit crap at pointing them out, but it'll open your mapping app to navigate you there.</p>\n\n<p>Many of the venues are in historic buildings, so don't expect lifts or escalators. Stairs all the way, baby!</p>\n\n<h2 id=\"harry-potter\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#harry-potter\">Harry Potter</a></h2>\n\n<p>Edinburgh seems like an inclusive and trans-friendly city. Half the acts on the Fringe proudly stated their LGBT+ credentials and most venues we went to had gender neutral loos.</p>\n\n<p>And then every other shop proudly boasts it is 100% definitely where JKR got the inspiration for Harry Potter. Tourists are schelpped between \"Diagon Alley\" and probably-the-cafe-where-she-wrote while slurping down dayglo butterbeers.</p>\n\n<p>Truly the duality of life!</p>\n\n<h2 id=\"comfort\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#comfort\">Comfort</a></h2>\n\n<p>There's an ancient Edinburgh byelaw which prohibits cushions on seats. No chair may be wide enough to accommodate anything other than the skinniest arse. It also places a moratorium on legroom.</p>\n\n<p>Ok, some of the venues were more comfortable than others, but prepare for a bit of backache.</p>\n\n<p>Toilets are plentiful in most venues, and theres no shortage of pubs to pop in to if you need refreshment or relief.</p>\n\n<p>Scotland isn't known for its heat, but some of the venues desperately need air-conditioning in their foyers and auditoriums. A few were handing out free water to the swealtering punters - but probably best to bring your own</p>\n\n<h2 id=\"would-i-come-here-again\"><a href=\"https://shkspr.mobi/blog/2026/08/thoughts-on-the-edinburgh-fringe-as-a-newbie/#would-i-come-here-again\">Would I Come Here Again?</a></h2>\n\n<p>Yeah! I reckon so! Probably not next year, and probably with more of a plan about which \"must sees\" I wanted to see.</p>\n\n<p>Staying closer to the centre is more expensive, but might have made it easier to see some if the shows later in the night.</p>\n\n<p>There is <em>so</em> much talent, <em>so</em> much variety, and <em>so</em> much joy in the city that it becomes rather infectious.</p>\n\n<p>If you can afford the train fare, hotel costs, tickets, booking fees, pints, chips and all the other people desperate to stick their hands into your wallet - then it is a great adventure.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74021&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "EdFringe",
"term": "EdFringe",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=72687",
"title": "Book Review: Slags by Emma Jane Unsworth ★★★⯪☆",
"description": "I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia. It reminds me of this excellent essay by Marie Le Conte about consent. What can a teenage girl…",
"url": "https://shkspr.mobi/blog/2026/08/book-review-slags-by-emma-jane-unsworth/",
"published": "2026-08-15T11:34:42.000Z",
"updated": "2026-06-29T19:43:11.000Z",
"content": "<img src=\"https://shkspr.mobi/blog/wp-content/uploads/2026/06/slags.webp\" alt=\"Book cover featuring a teenage girl smoking.\" width=\"200\" class=\"alignleft size-full wp-image-72688\">\n\n<p>I'm really not sure what to make of this book. It was recommended by my book club as something between tragedy and comedy. The characters are excruciatingly well written - if you (or your friends) shoplifted Impulse body-spray back in the 1990s, you'll be hit by a terrifying wave of nostalgia.</p>\n\n<p>It reminds me of this excellent <a href=\"https://youngvulgarian.substack.com/i/152315586/a-column\">essay by Marie Le Conte about consent</a>. What can a teenage girl consent to? What will fuck her up for years to come? What if she doesn't mind being a <em>little</em> fucked up?</p>\n\n<p>The prose is amazing, the plotting perfectly paced, and the denouement satisfying - with lots of retrospectives \"Oh! I get it now\"s.</p>\n\n<p>Despite the hectic and hilarious story, I still felt a little sordid reading it. There's a streak of sadness running through it, intertwined with some unbearably heartbreaking poetry.</p>\n\n<blockquote><p>It’s always raining and there’s nothing to do except dream and they don’t even give you much time to do that with all the coursework.</p></blockquote>\n\n<p>It is entertaining and fun - but you need a strong stomach and a casual disregard for the overall happiness of your protagonists.</p>\n\n<p>One note - there are a few odd / broken styles in the ePub. Nothing too disruptive, but some passages have a slightly smaller font size for no discernable reason.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=72687&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "Book Club",
"term": "Book Club",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Book Review",
"term": "Book Review",
"url": "https://shkspr.mobi/blog"
}
]
},
{
"id": "https://shkspr.mobi/blog/?p=74018",
"title": "Edinburgh Fringe: Target Audience ★★★★★",
"description": "Easily the best show I've seen at the Fringe. For plot-related reasons, a television company asks a literary genius to create a \"pro-weapons sitcom\". It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night. All four of the cast are spectacular. Turning the…",
"url": "https://shkspr.mobi/blog/2026/08/edinburgh-fringe-target-audience/",
"published": "2026-08-14T18:45:41.000Z",
"updated": "2026-08-14T18:10:20.000Z",
"content": "<p>Easily the best show I've seen at the Fringe.</p>\n\n<p>For plot-related reasons, a television company asks a literary genius to create a \"pro-weapons sitcom\".</p>\n\n<p>It is a fast paced mix of the sitcoms 2012 and Episodes. The jokes come at a steady pace - some attack with the furiousity of bullets, others the the subtlety of a knife in the night.</p>\n\n<p>All four of the cast are spectacular. Turning the sometimes-stock characters into powerful avatars. The amoral Zuckerbergian horror of data driven decision making is the perfect manure in which to grow comedy roses.</p>\n\n<p>It stands well against any classic farce and I hope it tours until the end of the world.</p>\n\n<p>A special shout out to the Pleasance Above for being the most comfortable venue in Edinburgh! Raked auditorium, cushioned seats, and air conditioning all make for a delightful theatrical experience.</p>\n<img src=\"https://shkspr.mobi/blog/wp-content/themes/edent-wordpress-theme/info/okgo.php?ID=74018&HTTP_REFERER=Atom\" alt width=\"1\" height=\"1\" loading=\"eager\">",
"image": null,
"media": [],
"authors": [
{
"name": "Terence Eden",
"email": null,
"url": "https://edent.tel/"
}
],
"categories": [
{
"label": "comedy",
"term": "comedy",
"url": "https://shkspr.mobi/blog"
},
{
"label": "EdFringe",
"term": "EdFringe",
"url": "https://shkspr.mobi/blog"
},
{
"label": "Theatre Review",
"term": "Theatre Review",
"url": "https://shkspr.mobi/blog"
}
]
}
]
}