Security Analysis and Improvement of Railway Vehicle-to-ground Authentication and Key Negotiation Protocol

Authentication and key negotiation are the basis for safe railway operation. In response to the security risks of the LTE-R authentication process for next-generation railway wireless communication systems, improvements are made in the framework of the EPS-AKA protocol to generate anonymous identities that will be updated after each authentication, with a timestamp added while the protocol is being executed. The key negotiation phase enables the update of the long-term shared key, eliminating the risk of long-term shared key K leakage. The improved protocol not only achieves IMSI confidentiality protection and resists replay attacks, but also provides forward security. Security and performance analyses show that the improved protocol outperforms existing schemes in terms of computational cost and can meet the requirements for secure and efficient vehicle-to-ground authentication.