Perfect Forward Secrecy (1 mark) The following Key Exchange Algorithm (KEA) was designed by the NSA of the US government It is a variant of the Diffie-Hellman protocol. Each user P has a private key rp and public key gP mod p. Let rp be a random number selected by user P. A B:g mod p A+ B:g mod p Shared Key: K ggB mod p Does the KEA protocol provide the Perfect Forward Secrecy? Please justify your answer. Note: 1) rA and rB are random numbers selected in each session, neither of them will be reused in other sessions. 2) A and p are long-term keys here