You must have forgotten the "rotating cleartext". I don't remember how well defined it was in the book, but it sounded like it means the decrypted message coul

You must have forgotten the "rotating cleartext". I don't remember how well defined it was in the book, but it sounded like it means the decrypted message could change out from under them, without being decrypted. Like the encryption was itself a running program they had no control over that could be magically updated remotely. IIRC though, the whole thing ended up being a ruse, a virus made to look like an encrypted message, designed to destroy that specific supercomputer. Digital Fortress was also the only Dan Brown book I've read, and later when I started college, one of the other students said it was the reason he decided to take Computer Science. I kinda winced and wasn't really sure what to say.