Comment by simonw
13 hours ago
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.
Signing the transmission isn't enough to prevent a replay attack.
It should be if each message includes an incrementing counter and the clients keep track of which counters they have already seen.
You don't actually need the signing if you have the counters (if your ~only goal is to prevent replay attacks of that form).
Yes, exactly, signing the transmission is not enough.
You've just added a nontrivial amount of memory usage as well that will look a lot like a memory leak as it grows.
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