A Fog-Based Decentralized Lightweight Revocation Protocol for Sybil-Resistant 5G Vehicular Networks

The accelerated implementation of fifth-generation (5G) vehicular networks has escalated security issues, with Sybil attacks representing a significant threat, since malicious vehicles use pseudonym mechanisms to forge multiple identities and sabotage trust-based services. Currently deployed certificate revocation techniques have a highly centralized model, result in large latency time and lack scalability with insecure privacy because of the dynamically changing vehicular environment. In this paper, we propose a fog-based decentralized lightweight revocation protocol (FD-LRP) to overcome the above shortcomings for Sybil-resistant 5G vehicular networks. The research novelty is the development of a realtime revocation service, which features suspicion-based scoring at fog nodes, and collaborative multi-fog consensus mechanism to swiftly and effectively isolate malicious vehicles without pre-maturely revealing long-term identities. FD-LRP also presents a light-weight certificate revocation list (WL-CRL) that forwards only the hashed-pseudonyms with delta messages, decreasing the communication and storage overhead. Performance of FD-LRP is evaluated by comprehensive simulation, and shows the up to 96.5% accuracy in Sybil detection, with less than 7 ms as average time of L-CRL update operation. We verify that FD-LRP is an efficient, privacy-preserving and viable revocation mechanism for the future 5G vehicular networks based on our results.