Cribs in the Voynich MS

[Mark Knowles]

On the subject of why innovative features of Milanese ciphers from the Voynich manuscript don't survive into Milanese ciphers later in century my thinking if that practicality is key. The purpose of a cipher is not only to make it difficult for someone without the key to break, but also that it needs to be as easy as possible for someone with the key to encrypt and decrypt messages and also easy for the cipher clerk to generate a new cipher key when needed. My hypothesis is that at some stage Milanese ciphers were simplified and standardised as they had become too difficult for ordinary diplomats to use and some of the more sophisticated features were dropped.