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)