Fable 5.1 cracked a 373-year-old cipher in 44 minutes, 176k tokens and zero human interjections

Vals AI (corroborated by r/singularity, 502 upvotes)·high signalXBlueskyLinkedInCopy link

Vals AI reported that Fable 5.1 decoded Sir Thomas Urquhart's Cyphral Distich, published in 1653 and listed #28 on Klaus Schmeh's "Top 50 unsolved encrypted messages," in 44 minutes using 176k tokens with no human intervention. The insight was structural rather than cryptographic: the two lines of 32 numbers sit immediately after Urquhart's 32 Proquiritations, so each number indexes a word position within the proquiration at that position, and the first letters of the selected words spell the plaintext. Centuries of human attempts using frequency analysis, substitution and homophonic substitution failed on it; the r/singularity thread hit 502 upvotes and 157 comments.