Comment Re:Is this technically impossible - no. (Score 1) 191
What you're describing is a random number generator with a key to initialize it. Some of the good ones might be good enough (or might not). Anything you can keep in your head is going to be crap and fairly easily breakable. Either way, you're still better off to just exchange regular secret keys at your meeting, which can be concealed in a variety of ways. Even real one time pads can be fairly easily concealed - a "blank" USB key, for example.