Consider the following mutual authentication and key establishment protocol, which uses a timestamp T and public key cryptography.

For each of the following cases, explain whether or not the resulting protocol provides an effective means for secure mutual authentication and a secure session key K. Ignore replay attacks based solely on the clock skew.

A.) Message 1: {[T,K]Alice}Bob

B.) Message 1: {"Alice", [T,K]Alice}Bob

C.) Message 1: "Alice", {[T,K]Alice}Bob

D.) Message 1: T, "Alice", {[K]Alice}Bob

E.) Message 1: "Alice", {[T]Alice}Bob and let K = h(T)

Message1 Bob Alice