On the security of an anonymous roaming protocol in UMTS mobile networks

In this communication, we first show that the privacy-preserving roaming protocol recently proposed for mobile networks cannot achieve the claimed security level. Then we suggest an improved protocol to remedy its security problems

A Unlinkable Delegation-based Authentication Protocol with Users’ Non-repudiation for Portable Communication Systems

[[abstract]]For portable communication systems, the delegation-based authentication protocol provides efficient subsequent login authentication, data confidentiality, user privacy protection, and non-repudiation. However, in all proposed protocols, the non-repudiation of mobile users is based on an unreasonable assumption that home location registers are always trusted. To weaken this assumption and enhance the nonrepudiation of mobile users, a new delegation-based authentication protocol is proposed. The new protocol also removes the exhaustive search problem of the subsequent login authentication to improve the subsequent login authentication performance. Moreover, the user unlinkability in the subsequent login authentication is also provided to enhance the user identity privacy protection.[[incitationindex]]EI[[incitationindex]]CEPS[[booktype]]紙