we show an authentication protocol for the stateless server Bob to authenticate a user Alice, which is not secure. Now let's modify the protocol as follows: Bob is still a stateless server and it sends both a challenge, and the challenge encrypted with a key that only he knows, to Alice. Alice then sends the received encrypted challenge back to Bob, together with the same challenge encrypted with the shared secret key between Alice and Bob

l am Alice C) Is this protocol secure? Explain why or why not