Certificateless one-pass and two-party authenticated key agreement protocol and its extensions

An authenticated key agreement protocol is used to share a secret key for encrypting data being transferred between two or more parties over a public network. In this paper, we study one-pass and two-party authenticated key agreement protocols in certificateless public key cryptography. We first define a security model for certificateless one-pass and two-party authenticated key agreement protocols and then propose a concrete certificateless one-pass and two-party authenticated key agreement protocol which has low transmission overhead. Our protocol captures several common security requirements that a one-pass and two-party authenticated key agreement protocol should satisfy. We prove the security of our protocol under the computational Diffie-Hellman, square computational Diffie-Hellman and gap bilinear Diffie-Hellman assumptions in the random oracle model. Two extensions with better security attributes are also proposed.