Secure and Efficient Authentication and Key Agreement Scheme for Multicast Services in 5G Vehicular to Everything

In 5G Vehicular to Everything (5G-V2X), service messages are provided to a group of vehicles belonging to a specific region by means of point-to-multipoint transmission. To address security threats and privacy leakage, an authentication and key negotiation scheme is proposed for multicast service message transmission between content providers and vehicles. A certificate-less aggregated signature technique is used to batch-verify all vehicles in the group, and improves the efficiency of authentication requests. Secure key negotiation is realized based on the polynomial key management technique, which makes it impossible for illegal users or the core network to obtain the shared session key. Finally, a dynamic key update mechanism for vehicles in the group is implemented, so that when a vehicle joins or leaves the group, the content provider only needs to send a key update message to update the session key. The proposed scheme can guarantee security requirements such as anonymity, unlinkability, forward and backward security, and resistance to conspiracy attacks, as shown by formal verification tools and further security analysis. The computational efficiency is improved by about 34.2% compared to existing schemes. © 2024 Science Press. All rights reserved.