I need to verify that two messages, that came over distinct channels, come from the same origin:
- without knowing anything about the origin beforehand
- the channels are one-way, only one message may be sent over each
- the sender can have recipients public key
The sender has a random number that identifies them. Apparently I can send the ID encrypted with two different public keys, one for each channel? Is there some simpler method? I was thinking about something like two commutative functions, f and g so that f(g(x)) == g(f(x))? I don't need to know the ID and it would be a bit safer if I didn't. I just need to know that the messages are from the same sender.