Hydrophonic PGP (Score 1)

This hits me as a fundamentally new twist on public/private key encryption. I send you my public key (a ping) which you then use to encode a message back to me. Doesn't matter if someone hijacks the ping, because the ping will "appear" differently to them. They can still transmit to me, but they can't decrypt any other message sent from ANY other position, even if they record it and then move into the original transmitting position later. It's almost like a dynamic public key. Very cool.