An enhanced one-round pairing-based tripartite authenticated key agreement protocol

Abstract

A tripartite authenticated key agreement protocol is generally designed to accommodate the need of three specific entities in communicating over an open network with a shared secret key, which is used to preserve confidentiality and data integrity. Since Joux proposed the first pairing-based one-round tripartite key agreement protocol in 2000, numerous authenticated protocols have been proposed after then. However, most of them have turned out to be flawed due to their inability in achieving some desirable security attributes. In 2005, Lin-Li had identified the weaknesses of Shim's protocol and subsequently proposed their improved scheme by introducing an extra verification process. In this paper, we prove that Lin-Li's improved scheme remains insecure due to its susceptibility to the insider impersonation attack. Based on this, we propose an enhanced scheme which will not only conquer their defects, but also preserves the desired security attributes of a key agreement protocol. © Springer-Verlag Berlin Heidelberg 2007.