An Attribute-Based Pre-Authenticated Secure Communication Protocol Enabling Key Protection and Credential Online-Upgrading for 5G NR V2X

Currently, no practical lightweight authenticated key agreement (AKA) protocol with fine-grained pre-authentication has been developed to address security issues such as data integrity, authenticity, traceability, tamper-proofing, and privacy in 5G NR V2X. In this paper, we introduce a lightweight anonymous attribute-based signature of knowledge (Lw-AABSoK) scheme built on Curve25519 to defend against key-leakage attacks. This scheme enables attribute revocation and online credential updating, serving as a fine-grained pre-authentication cryptographic module for V2X secure communication. Leveraging the proposed Lw-AABSoK, we design an end-to-end fine-grained pre-authenticated key agreement protocol (E2E-FGpAKA). The E2E-FGpAKA is UDP-compatible; all interactive messages are self-validated by the Lw-AABSoK, and their sizes are strictly below the 5G NR MAC Transport Block Size (TBS). Through rigorous comparative analysis, scientific experimental verification, and comprehensive evaluation, it is evident that the proposed scheme holds significant practical value for 5G NR V2X.