LAUSR

The authentication protocols are implemented to provide identity authentication for communication entities. With the increasing demand of network security and the development of technology, the anonymous authentication protocol for LBS (location based service) has gradually become a research hotspot and attracted extensive attentions, which provides anonymity of the user, confidentiality of location information and identity authentication simultaneously. An efficient and secure anonymous authentication protocol with enhanced privacy for location based service using asymmetric cryptography was proposed by Memon et al. in 2015. However, some scholars pointed out some weaknesses of Memon et al.’s protocol, such as the lack of resistance to password change attack, privileged insider attack and offline password guessing attack. They also pointed out the protocol failed to prevent adversaries from getting the session-specific temporary information. Besides, the mutual authentication was not perfect. Therefore, in this paper, we further analyze the security of Memon et al.’s protocol and propose an improved anonymous authentication protocol for location based service. We use the timestamp mechanism and rely on CDH (Computational Diffie-Hellman) problem to improve security primarily. The security of the proposed protocol is verified using BAN logic and the performance comparison and efficiency analysis are carried out. The results show that our improved protocol has higher security with little more computation cost.