Changes

Under mutual authentication, one of the two systems creates a challenge code which it transmits to the other system. The second system in turn generates a response using the received challenge code and also creates its own challenge code, and are both transmitted back to the original system. The original system validates the response code and returns its own response code based on the challenge code send from the second system. Once the second system has validated its own response code from the original system it sends an acknowledgment message and authentication is complete.