B-bKM & LDP: a secure, cost-effective and efficient key management system for social internet of vehicles

The Social Internet of Vehicles (SIoV) combines vehicular networks with social networking principles to support advanced services such as entertainment, personalized recommendations, and smarter route planning. Despite its potential, SIoV faces major challenges due to its highly dynamic environment, including secure key management, protection of location privacy, scalability, and communication latency. Additionally, adaptability, scalability, and efficient resource discovery remain major challenges in SIoV environments. To overcome these issues, this article introduces B-bKM, a blockchain-based key management framework strengthened with Local Differential Privacy (LDP). The proposed approach redesigns the traditional blockchain architecture by incorporating three key features: (i) a lightweight miner election mechanism to reduce overhead, (ii) personalized transaction chains that allow vehicles to securely manage and migrate cryptographic keys, and (iii) LDP-based location perturbation to safeguard users’ privacy. Unlike cloud-dependent solutions, B-bKM distributes trust across the network and removes single points of failure by limiting blockchain operations to cluster heads. Extensive simulations using real vehicular mobility data show that B-bKM significantly lowers communication latency and transmission costs while improving throughput and achieving stronger k-anonymity compared to existing baseline schemes. These results demonstrate that B-bKM offers a secure, efficient, and privacy-preserving key management solution suitable for large-scale SIoV systems.