It goes without saying that you can't provide a key in advance that will result in convincing "fake" plaintexts for every encrypted message you send. The conten

It goes without saying that you can't provide a key in advance that will result in convincing "fake" plaintexts for every encrypted message you send. The content of the fake plaintexts has to be fully encoded in the key+any "randomness" value (it can't come from anywhere else).