If I had the free time, I&#x27;d create a cryptographic protocol running on top of telnet that looked like someone playing a MUD.<p>For email, you&#x27;d encrypt data to have it look like regular prose.  So you&#x27;d only get a few bits per English word, but that would be sufficient for short messages.  Could also make use of extra spaces in between words.<p>The real trick with that would be to take an existing document, and alter it to encode a message.  So you&#x27;d be doing things like using synonym choice to get your bits.