Suppose that a user A wants to send a secret message to user B. User A has their own private and public RSA key-pair. User B also has their own private and public RSA key-pair. Both users are aware of the other's public keys because their certificates were signed by a trusted CA. Say that user A sends user B a secret message M using the protocol below. Here, K is a random symmetric key, K{M} is message M encrypted using K, and [K]A is K encrypted using A's private key. A to B>K{M},[K]A Does the above protocol guarantee message confidentiality? If yes, what are your justifications for the response? If no, what are your justifications and how would you update the protocol to guarantee message confidentiality