Alice wants to communicate with Bob, using public-key cryptography. She establishes
a connection to someone she hopes is Bob. She asks him for his public key and
he sends it to her in plaintext along with an X.509 certificate signed by the root CA.
Alice already has the public key of the root CA. What steps does Alice carry out to
verify that she is talking to Bob? Assume that Bob does not care who he is talking to
(e.g., Bob is some kind of public service).
