An Enhanced Authentication Scheme with Privacy Preservation for Roaming Service in Global Mobility Networks

Global mobility network (GLOMONET) provides global roaming service to ensure ubiquitous connectivity for users traveling from one network to another. It is very crucial not only to authenticate roaming users, but to protect the privacy of users. However, due to the broadcast nature of wireless channel and resource limitations of terminals, providing efficient user authentication with privacy preservation is challenging. Recently, He et al. proposed a secure and lightweight user authentication scheme with anonymity for roaming service in GLOMONETs. However, in this paper, we identify that the scheme fails to achieve strong two-factor security, and suffers from domino effect, privileged insider attack and no password change option, etc. Then we propose an enhanced authentication scheme with privacy preservation based on quadratic residue assumption. Our improved scheme enhances security strength of He et al.’s protocol while inheriting its merits of low communication and computation cost. Specifically, our enhanced scheme achieves two-factor security and user untraceability.