Before Ordo will decrypt the file, it needs to have the private key: all 4096 bits of it. The key is stored on Randy’s hard disk. But bad guys can break into hotel rooms and read the contents of hard disks, so the key itself has been encrypted. In order to decrypt it, Ordo needs the key to the key, which (in Cantrell’s one concession to user-friendliness) is a pass phrase: a string of words, easier to remember than 4096 binary digits. But it has to be a long phrase or else it’s too easy to break.