Claude Fable 5.1 Solves 373-Year-Old Scottish Cipher

Published: 2026-09-15 03:03:23 |

Anthropic’s Claude Fable 5.1 has reportedly solved the 373-year-old Cyphral Distich cipher in 44 minutes, using 176,000 tokens without human intervention, according to AI evaluation firm Vals AI. The cipher was created by Scottish royalist Thomas Urquhart in his 1653 book Logopandecteision and consists of two 32-number lines. Claude Fable 5.1 identified the book itself as the key. Each number points to the corresponding one of 32 surrounding passages, with the number indicating which word to select. Taking the first letter of each selected word produced a prayer supporting King Charles II: “O GOD UPHOLD KING CHARLS THE SECOND AND MAKE HIM THE SUPREME RULER OF THIS LAND.” Vals AI said the result is supported by the 32-letter structure of each line, the rhyme between “and” and “land”, and Urquhart’s known royalist views. Claude Fable 5.1 also produced a possible solution for Urquhart’s larger Cyphral Octastich, but nine characters remain unresolved and page numbering appears to shift. The findings have not yet been independently verified by cryptography historians. The Claude Fable 5.1 breakthrough highlights AI’s potential in historical text analysis and puzzle solving, but the lack of external verification means the claims should be treated cautiously.

Neutral

This is a technology and historical cryptography story, not a direct cryptocurrency market event. It contains no new information about Bitcoin, Ethereum, digital-asset regulation, blockchain adoption, liquidity, or institutional flows, so the immediate trading impact is likely neutral. Short-term market reaction should be limited to sentiment around artificial intelligence. AI-related tokens or companies could receive brief speculative attention if traders interpret the result as evidence of stronger model capabilities. However, similar AI breakthroughs have generally produced temporary, narrative-driven moves rather than sustained changes in crypto fundamentals. The report is also based on Vals AI’s account and has not been independently verified, which reduces its credibility as a market catalyst. Over the long term, continued progress in AI could influence crypto through automated trading, cybersecurity, decentralized computing, and AI-focused blockchain projects. Those effects would depend on confirmed technical advances, commercial adoption, and capital flows into related sectors. This single cipher-solving claim does not provide enough evidence to alter broader market direction or stability.