alt Hacker NewsYou shouldn't be talking down like this, you're wrong about it. Alice and Bob need to exchange keys beforehand in some trusted out-of-band way. There's no protocol that solves this if Eve can be in the middle. I'm not sure what you mean by fingerprints, but if you describe a protocol, I can describe the mitm attack.
You’re not sure what key fingerprints are?
Bob and Alice are setting up their e2e channel, and because they have some extra level of concern about snooping, they telephone each other and read off some form of hash of the public key to each other.
A more complex variant would be something like PGP implemented, where Bob and Alice could both sign each others keys after this exchange, ensuring that someone who hadn’t met Bob but did trust Alice could inherit trust in Bob’s Alice-signed key.
You’ve stated unequivocally that I’m wrong, so now, please show your homework.