Secure Vehicle Platooning Protocol for 5G C-V2X

Recently frozen 3GPP standard Release-16 has introduced vehicle platooning as a novel application in 5G Cellular Vehicle-to-everything (C-V2X), which is a technique to organize a group of close-following vehicles in column, aiming to improve traffic throughput and reduce fuel consumption. However, existing platoon protocols only focused on efficiency and ignored security. In this paper, we present a secure vehicle platooning protocol for 5G C-V2X with fast mutual authentication and efficient group key management. The protocol provides all maneuvers including merging, split, and member leaving with superior independence and flexibility. Relying on the enhanced 5G Authentication and Key Agreement (AKA) procedure, pseudo identity and signcryption keys are generated for each vehicle on startup by 5G Core Network (5GC) for conditional anonymity and mutual authentication. Then, a protocol suit covering all platooning maneuvers is proposed based on group key distribution and updating. To prove the security of the proposed protocol, the Tamarin tool was employed to give a formal security verification under Dolev-Yao (DY) model. In addition, performance is analyzed in terms of computation cost and communication overhead, demonstrating its efficiency in authentication and group management.