Design a protocol that will establish a new shared secret key K between Alice and Bob without help of a third party. You can use any symmetric cryptographic mechanisms, but at the end of the protocol the following conditions must be met: Mutual authentication of Alice and Bob. . The protocol must provide key agreement. Explicit key authentication. Your answer should be in the form of a protocol diagram between the parties, and you must clearly state your assumptions, explain all actions performed by both par- ties and define all your variables and notation.