Provably secure extended chaotic map-based three-party key agreement protocols using password authentication

This paper presents a novel three-party key agreement protocol using password authentication, which enables each client sharing a long-lived secret only with a trusted server to exchange confidential and authenticated information with another client over an insecure network via the server. The proposed protocol is based on extended chaotic maps and adopts the technique that the clients can publicly exchange the factors for generating the session key without the help of the server such that the numbers of transmissions are reduced. A round-efficient version of the proposed key agreement protocol is also described. Compared to related chaotic map-based approaches, the proposed protocol not only possesses higher security and lower computational cost, but also has fewer transmissions. Additionally, the proposed protocol is proven secure in the random oracle model and realizes optimal in communications.