The enigma of Lorenzo Ventura’s cipher

Abstract

The aim of this research was to find the algorithm used in the ciphers mentioned by Blaise de Vigenère in his treatise, where he states that in 1569, while in Venice, he learned about a steganographic cipher by a certain Lorenzo Ventura, similar to Tritemio’s Ave Maria. It had been used by the bailo in Constantinople after Sultan Selim II prohibited him from writing his dispatches in cipher. Now that a collection of letters, notes, and handwriting examples belonging to Ventura has been found in the State Archives of Venice, initial findings emerge that confirm, at least in part, Vigenère’s claims.