Computer Science / / Cryptology

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