Improving the X.509 protocol for ATM networks
The number of authentication protocol message exchanges should be kept to a minimum for ATM networks. For the three-way X.509 protocol, we have however identified possible extra message exchanges necessary to obtain the public key (and its certificate) before the execution of message one. We propose an improvement on the protocol in which the public key certificates of each communicating party are piggyback with message one and two, therefore eliminating the need to access the directory for these certificates. This approach ensures that a three-way protocol always involves only three messages exchanges. Protocol performance is also enhanced by avoiding an extra signature generation and verification.