The cipher I reconstructed some years ago and call "Cipher with Don Juan de Borgia (1579)" turned out to be the same as the one reconstructed by Deovos (p.414). I reflected this finding in "Spanish Ciphers during the Reign of Philip II".
So many different ciphers were in use in history, and it is hard to find out whether a cipher one is dealing with is already known elsewhere. I myself have noted multiple times that one cipher found in one source is the same as another cipher in another source. When I reconstruct a cipher, I always check whether it is already among the known ciphers (collected on my website), but this one slipped my check.
I found this cipher is the same as Cp.30 printed in Devos. When I was examining specimens in this cipher, I found alphabetical letters in the ciphertext occasionally represented the letter itself (like "m" in the ciphertext representing plaintext "m"). Such trivial substitution reminded me of Cp.30, which I described in "Philip II's Trivial Substitution Cipher".
ReplyDeleteSo, Devos himself reconstructed the same cipher without knowing it is Cp.30. The same cipher was independently reconstructed by Bernard Allaire (1997). So, at least three people reconstructed this cipher!