I have enciphered plain-language messages and deciphered encrypted messages in my career, and always took it for granted that I was either making the underlying text unreadable in the former case or readable in the latter, using a cipher (or key).
So I would have to come down on the side of those who feel that cipher, as used in this case, was meant to evoke an image of mystery or insolubility, but was in fact used incorrectly.