An enhanced mutual authentication and key agreement scheme for mobile user roaming service in global mobility networks

Roaming service is required in the ubiquitous access used in the global mobility networks (GLOMONETs) and the security is one of the most important issues. Many researchers focus their interests on authentication schemes for GLOMONETs. In 2015, Gope and Hwang, Zhang et al. and Farash et al. proposed their key agreement authentication schemes for GLOMONETs, respectively. However, we find weaknesses in them. Gope and Hwang’s scheme is under the off-line guessing attack and the de-synchronization attack. Moreover, it does not keep strong forward security and the session key is known by the home agent. Zhang et al.’s scheme has several weaknesses including vulnerability to the off-line guessing attack, destitution of password change phase, and the leakage of updated session key. Farash et al.’s scheme lacks user anonymity and strong forward secrecy and is vulnerable to the off-line password guessing attack. The session key is known to the home agent, too. Furthermore, neither Gope and Hwang’s scheme nor Farash et al.’s scheme has the session key update phase. To eliminate the problems, we present an improved authentication and key agreement scheme for GLOMONETs. According to the formal proof and the informal analysis, our scheme is well-performed and applicable.