Cyphersolver — Unsolved Historical Ciphers: an open ledger of decipherments, contributors and corrections
A running public ledger, begun September 2026 by Daniel Bourdeau with Claude, that logs attempts on 496 historical ciphers (1398–1991) and records for each how the text was obtained: 162 keys recovered by cryptanalysis, 213 read with keys or decipherments that already existed, 89 closed without a reading, with every write-up saying why. It now takes outside contributions and keeps an open catalogue of 84 undeciphered letters. Its adjudication of the Voynich manuscript concludes it is probably meaningful-looking nonsense rather than a disguised language, since the text is far too predictable for any simple cipher of the European languages tested.