"But, after all," he reflected before turning into her room, "what has occurred? Nothing. She had a long conversation with him. Well, what harm is there in that?" ... and as soon as he re-entered the dark drawing room a voice would whisper that it was not so, and that if others noticed, that showed there was something to notice. - Tolstoy Anna Karenina from Charles Rackoff, Daniel R. Simon, "Cryptographic Defense Against Traffic Analysis" (1993)