Security and Efficiency Enhanced Authentication Scheme Based on Self-Updated Hash Chain for Train-Ground Communication

Aiming at the special requirement of security and real-time performance in next generation high-speed railway wireless communication system, long term evolution-railway (LTE-R), a security and efficiency enhanced train-ground authentication scheme based on self-updated hash chain is proposed. In the scheme, the master key of home subscriber sever (HSS) is used for encrypting the anonymous variable temporary identity (TID) of the on-board unity (OBU) so as to protect the privacy of OBU and resist the desynchronization attack. In order to realize efficient mutual authentication between the train and the service network, hash chains are used to replace the authentication vectors, and the local updating of hash chains can avoid restarting the full-authentication protocol caused by exhaustion of authentication vectors. Moreover, by using the identity ticket issued by the mobility management entity (MME), seamless handover-authentication can be realized in coordination with base stations. Security and performance analysis shows that compared with the long term evolution (LTE) standard protocols under the same condition, the computation cost of the proposed full-authentication protocol, re-authentication protocol and handover-authentication protocol is reduced by 41.67%, 44.44%, and 45.45% respectively, and the traffic is reduced by 62.11%, 50.91%, and 84.91% respectively, which can meet the security and real-time requirements of LTE-R network.