Let's recap the TLS Handshake.
There's an important part of it that we haven't focused on yet.
The first step is the hello from the client to server.
The second step, the server responds--both of these messages include new randomness,
and part of this response is the certificate.
In the third step, the client sends a new random value encrypted with the server's public key.
At the end of this process, the client and the server have agreed on the master secret,
which is used to derive the keys for communication.
So the key question and the goal of the protocol is for the client to know
that it's communicating with the correct server,
and that that master secret is only shared with the server it intends to communicate with.
The question is how can the client trust that it's communicating
with the server it intends to communicate with.
Here are the choices, select the best answer, and I should warn you
this is a bit of an unfair question since we haven't talked about this yet,
but I think you'll know enough to figure out the answer based on what you've seen so far.
