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.