Bootstrapping the encryption is a problem: until you've run the handshake, you don't have a key with which you could encrypt the handshake. And you don't want

Bootstrapping the encryption is a problem: until you've run the handshake, you don't have a key with which you could encrypt the handshake. And you don't want the key to live for too long, so folk are going to end up trying to use expired keys. Between the article and the linked introduction, all of what you are looking for is explained.