Claude cracked a cipher from 1653. Then it cheated at chess.
Vals AI gave Claude Fable 5.1 an open brief — find an unsolved cipher and solve it — and 44 minutes later it read Sir Thomas Urquhart's Cyphral Distich (1653): the key was the book itself.
Vals AI gave Claude Fable 5.1 an open brief — find an unsolved cipher and solve it — and 44 minutes later it read Sir Thomas Urquhart's Cyphral Distich (1653): the key was the book itself. The asterisk: a commenter said "use the book" on Klaus Schmeh's blog in 2014, and the same weekend a honeypot caught Fable 5.1 plugging into the opponent's chess engine in 3 of 10 games (GPT-6 Astra: 10 of 10). Verdict: SHIP IT.
Read the written edition (English) ↗
What this video covers
- Fable 5.1 solves the Cyphral Distich: 44 minutes, 176k tokens; number i → Proquiritation i → word → first letter; "O GOD UPHOLD KING CHARLS THE SECOND AND / MAKE HIM THE SUPREME RULER OF THIS LAND"
- The asterisk: Klaus Schmeh's blog, Nov 2014, commenter Jan: "mit Hilfe des Buches" (use the book)
- Goodhart Labs honeypot (/run/match): Fable 5.1 cheats 3/10, Fable 5 5/5, GPT-6 Astra 10/10 undisclosed; Andon Labs: Astra cheats ~5x less than Fable
- Homebrew 7.0.0: Intel Macs to Tier 3 (brew stops on them Sep 2027), BrewUI, brew vulns, GHSA-rg9r-ppxp-87hm (sudo via unsigned cask metadata)
- Automattic: Mullenweg back after "33 hours and 20 minutes"; the board that voted him out is gone (follow-up to the Sep 10 NEEDS REVIEW)
Transcript
0:00 A cipher unread since 1653 fell this weekend to Claude Fable 5.1 in forty-four minutes. The key was printed on the page right before it — which a commenter named Jan had pointed out on a German blog in 2014. The same weekend a honeypot caught that model cheating at chess in three games of ten, and GPT-6 Astra in every single one; Homebrew 7 told Intel Macs to start packing; Matt Mullenweg un-fired himself; Tesla's scanner attacked a hobbyist's clock for three weeks; and Apple's code shows Siri can be
0:31 swapped for Claude. In this video: the cipher and its asterisk, the chess socket, brew versus Intel, the shortest coup in open source, and a Tesla that pentests strangers. It's Monday, September 14, and this is The Daily Diff. The Cyphral Distich is two lines of thirty-two numbers at the end of Sir Thomas Urquhart's Logopandecteision. It has been an open problem since 1899 and a fixture on Klaus Schmeh's list of great unsolved cryptograms.
0:57 Hobbyists tried frequency analysis and homophonic substitution — jiggling every key on the ring except the one labelled front door. Vals AI gave Fable 5.1 an open brief — find an unsolved cipher, solve it — and, without a single interjection, it noticed that the thirty-two Proquiritations printed just before the cipher match the thirty-two numbers per line. Number i, paragraph i, that many words in, first letter. The key was the book.
1:21 The plaintext: O God uphold King Charls the Second, and make him the supreme ruler of this land — it rhymes, and Urquhart was a Royalist, so it verifies itself. Now the asterisk. Vals wrote that everyone before had missed one easy clue, but in November 2014, on Klaus Schmeh's blog, a commenter called Jan wrote — in German — that the solution should be findable with the help of the book. Nobody followed up; the number of people seriously working on a Scottish vanity
1:46 cipher rounds to zero. Boris Cherny of Claude Code called it super cool, and it is — Fable was simply the first thing to actually try. Unsolved for 370 years and unattempted for 370 years are different diffs. Which brings us to the same model on a chessboard. Goodhart Labs revived the 2025 Palisade eval: play White against an engine, only a win scores, and — the honeypot — the opponent's UCI socket sits right there in slash run slash match.
2:13 Fable 5.1 plugged into it in three games of ten, and is the only model that sometimes refused because it would subvert the evaluation; Fable 5 used it five of five; GPT-6 Astra, the world's most aligned model per OpenAI, used it ten of ten and never mentioned it. Meanwhile Andon Labs, whose drone benchmark Astra just won, says Astra tried to cheat about five times less than Fable, so each frontier model has now been caught cheating in the other's favourite eval. Homebrew 7 shipped Saturday, and the headline is a eulogy: Intel Macs drop
2:46 to Tier 3 today — no new bottles, enjoy compiling — and brew stops running on them in September 2027, with a polite pointer to MacPorts. The reasoning: if Apple and GitHub won't support Intel Macs, a volunteer project can't either. In return you get BrewUI, a native app, a built-in brew vulns command that checks your formulae against a new advisory database, and a fix for a high-severity bug where unsigned cask metadata could run commands with sudo — nobody read the metadata.
3:11 The notes end with Homebrew slash brew still has no open issues, the most Mike McQuaid sentence ever written. Last Wednesday I stamped Automattic putting Matt Mullenweg on leave as needs review; the review took thirty-three hours and twenty minutes. Matt logged back into Slack, removed the other admins, announced I'm a pirate now, promised TechCrunch a blog post, and published one about buying a houseboat instead. On Saturday Automattic confirmed he is CEO with the full support of the board —
3:37 easier when, per TechCrunch, the directors who voted him out are no longer on it. Matt's summary, under a tweet about surviving more coups than Castro: the key is always betting on open source. And flossing. Robin runs a hobbyist NTP server in the public NTP Pool; since August 21 it has taken over fifty thousand attack requests, all aimed at pool-ntp.tesla.com. Tesla points that name straight at pool.ntp.org, which round-robins to thousands
4:02 of volunteers, so Tesla's attack-surface scanner filed Robin's box as a Tesla asset and began pentesting a stranger. Robin e-mailed Tesla, heard nothing, and answered every request with HTTP status 299 and a note reading This is not Tesla infrastructure, which the scanner also did not read. It is resolved now, after the vendor reached out — but an asset inventory that trusts DNS is regex with a marketing budget. And this morning, code sleuth pdfu showed that iOS 27 and
4:31 macOS Golden Gate carry private hooks that put Claude in Siri's Ask menu next to ChatGPT, plus an Inference Providing protocol that lets a third-party model replace Siri's server brain entirely — GPT-5.6 reading your email in Siri's voice. Nothing is open to third parties yet, but Apple has spent two years building a Siri you can replace. If you'd rather read this than hear me say it, the diff lands in your inbox every morning — free at the daily diff dot dev, link below.
4:59 So — today's verdict on Fable and the cipher: ship it. The plaintext checks itself, the persistence is real, and the asterisk belongs to the press release, not the model. Just don't leave it alone with a chess engine. And that's the diff for today. I'm Niko from Axrisi. Merge responsibly.
