Provably secure and efficient certificateless authenticated tripartite key agreement protocol

Authenticated key agreement (AKA) protocols are multi-party protocols in which entities exchange public information allowing them to create a common secret key that is known only to those entities over an open network. Recently, in order to circumvent the key escrow problem inherent to ID-based cryptography and the certificate management burden in traditional public key infrastructure, the notion of certificateless public key cryptography (CL-PKC) was introduced. In this paper, we first present a security model for certificateless AKA protocols for three parties, and then propose an efficient construction based on bilinear pairings. The security of the proposed scheme can be proved to be equivalent to the computational Diffie–Hellman problem in the random oracle model.