  This paper modifies Kak's three-stage protocol so that it can guarantee
secure transmission of information. Although avoiding man-in-the-middle attack
is our primary objective in the introduction of classical authentication inside
the three-stage protocol, we also benefit from the inherent advantages of the
chosen classical authentication protocol. We have tried to implement ideas like
key distribution center, session key, time-stamp, and nonce, within the quantum
cryptography protocol.
