Beale ciphers (published 1885)
Three ciphers allegedly locating a buried treasure in Virginia were published in an 1885 pamphlet. One, solved against the Declaration of Independence, yielded a detailed account; the two others have never been convincingly decoded.
The Declaration-based 'solution' was accepted by some for decades.
Later analysis showed the source-text match depends on which edition and transcription you use, and the treasure has never been found.
A cipher 'solution' that hinges on a particular edition or source document is fragile — the same weakness critics cite in the Vals AI claim.
