This paper by Whitfield Diffie, Paul C. van Oorschot, and Michael J. Wiener discusses two-party mutual authentication protocols that provide authenticated key exchange, focusing on those using asymmetric techniques. The authors introduce a simple and efficient protocol called the station-to-station (STS) protocol, which is examined in detail and compared to existing protocols. The paper also defines what it means for a protocol to be secure and discusses desirable characteristics of secure authentication protocols. The authors emphasize the importance of linking key exchange with authentication to ensure that the shared key is only used with the authenticated party, not an imposter. The paper concludes with a summary of principles important in the design of authentication protocols.This paper by Whitfield Diffie, Paul C. van Oorschot, and Michael J. Wiener discusses two-party mutual authentication protocols that provide authenticated key exchange, focusing on those using asymmetric techniques. The authors introduce a simple and efficient protocol called the station-to-station (STS) protocol, which is examined in detail and compared to existing protocols. The paper also defines what it means for a protocol to be secure and discusses desirable characteristics of secure authentication protocols. The authors emphasize the importance of linking key exchange with authentication to ensure that the shared key is only used with the authenticated party, not an imposter. The paper concludes with a summary of principles important in the design of authentication protocols.