Provably secure entity authentication the three party case

In an open network-computing environment, a workstation cannot be trusted to identify its users correctly to network services. Authentication protocols provide an approach for the receiver of a message to ascertain its origin and to verify the identity of the sender in a distributed environment. However, most of the protocols have suffered from several kinds of attacks. Therefore, it is necessary to verify authentication protocols deliberately with such attacks as a basis. This work presents a new cryptographic protocol for an open network-computing environment. It describes the weaknesses and limitations in Kerberos protocol and shows how the new protocol overcomes these weaknesses and limitations. We also demonstrate how the new protocol provides an additional service, privacy, beside the authentication service in less number of messages than the previous authentication protocols.