An Authenticated Key Agreement Protocol Resistant to DoS Attack

Abstract

The Authenticated Key Agreement with Key Confirmation protocol proposed by Blake-Wilson et al improves the original Diffie-Hellman key agreement protocol and defeats the man-in-the-middle attack. But it is vulnerable to a Denial-of-Service (DoS) attack, because the responder must perform heavy modular exponential operations before he becomes sure about the identity of the initiator. A modification which forces the initiator to perform modular exponentiation first is presented in this paper. According to the analysis, it can defeat the DoS attack successfully, and provide mutual key authentication and key confirmation as well.