Efficient 3GPP Authentication and Key Agreement with Robust User Privacy Protection

Zhang et al. (2005) proposed an authentication key agreement protocol for 3GPP-AKA protocol. They claim that their protocol can withstand the redirection attack, the attack in corrupted networks, and can solve the operational difficulty with the sequence numbers problem. In wireless communications, identity privacy is an important security issue we concern. There are two abnormal cases that a mobile station (MS) must send its real identity to a visited location register (VLR) when authenticating at location updating. One is that VLR can not verify EVISI of MS and the other is that VLR can not reach the previously visited VLR. We can find out that the identity of the user are exposed when the adversary carries out the location privacy attack at location updating. For preventing the location privacy attack, users' identities must be protected for 3GPP-AKA protocol. However, we point out that Zhang et al.'s improved 3GPP-AKA protocol is vulnerable to the location privacy attack, having higher space overhead on VLR, and having higher bandwidth consumption between HLR and VLR. In this paper, we propose an efficient authenticated key agreement scheme for 3GPP-AKA to overcome all the drawbacks of Zhang et al.'s scheme.