Overview
- Independent researcher Michael A. Greshko detailed the Naibbe cipher in Cryptologia on November 26, 2025, proposing a verbose homophonic substitution method.
- The hand-executable system uses period-appropriate tools such as dice and playing cards, with tested variants based on 52- and 78-card decks.
- Outputs reproduce several hallmark patterns of the manuscript, including symbol frequencies, word-length distributions, positional glyph behavior, and an expanded slot grammar.
- Greshko reports the model remains incomplete, noting failures such as limited replication of Voynich B features and calling for modifications and computational testing.
- The findings keep the ciphertext hypothesis viable for the 15th-century, roughly 240-page manuscript, though alternatives like gibberish, an artificial language, or an unknown natural language are not ruled out.