Secure Certificateless Two-Party Key Agreement with Short Message

Abstract

Two-party key agreement protocol allows two communication parties to share a common key for secure communication. Constructed from the certificateless public key cryptography (CL-PKC), a certificateless key agreement (CL-KA) protocol can not only solve the key escrow problem inherited from identity-based systems, but also avoid the troublesome issue of certificate management. Although the topic of two-party CL-KA has been extensively studied during past few years, it is unknown whether such a protocol can be achieved with only one exchanged message. In this paper, we put this idea into practice and propose a new one-round CL-KA for two-party. Specifically, each party of the proposed protocol only has to transmit one group element for sharing a session key and still maintains low computational costs. Moreover, we analyze the security of our scheme in the extended Canetti-Krawzcyk (eCK) security model.