The Great Cipher

The Great Cipher: A nomenclator cipher developed by Antoine and Bonaventure Rossignol. Each number stood for a French syllable rather than single letters.

The Great Cipher was used to encrypt the King's most secret messages. In fact The Man in the Iron Mask's idenity was protected by the Great Cipher. The Great Cipher was not broken fnch wo centuries when Commandant Etienne Bazeries was able to take the most frequent occurring numbers to decipher one common word, les ennemis.