That's excellent!

I don't think that could be prevented, either. You could have the protocol exchange signing keys at the start and sign every message, but it's stretching the amount you can do with available audio bandwidth already so I expect that either wouldn't work or would become unbearably slow.

▲

dotancohen an hour ago | parent [-]

Signing the transmission isn't enough to prevent a replay attack.

	▲	simonw an hour ago \| parent [-]
		It should be if each message includes an incrementing counter and the clients keep track of which counters they have already seen.