
Brute Force and Book Keys: Claude Fable Decodes a 1653 Royalist Cryptogram
Vals AI tasked Anthropic's Claude Fable 5.1 with unprompted cryptanalysis, leading it to solve Sir Thomas Urquhart's 370-year-old Cyphral Distich by indexing directly into the text's own structural paragraphs rather than applying classical frequency analysis. The result is a humbling reminder of human oversight—the solution required no sophisticated math, only methodical patience, though reliance on automated search runtimes risks substituting genuine conceptual breakthroughs for brute-force persistence.
