First words on folio 1r

[Anton]

And again the ugly question: why are the cryptographers not able to decrypt a 15th c. cypher.

Well, they are not able to decrypt quite a number of ciphers which, to all probability, would not be very sophisticated. Zodiac ciphers, for example. Likewise, one could ask a question: "why 17th c. scholars (such as Marci or Baresch) were not able to read a readable 15th script".

Quite a number of old ciphers were deciphered only recently, such as e.g. the Copiale cipher, the tables of Soyga or some Trithemian stuff.