BLDSS: A Blockchain-Based Lightweight Searchable Data Sharing Scheme in Vehicular Social Networks

Vehicular social networks (VSNs) are likely to play an increasingly important role of the future smart cities, supporting traffic management, real-time warning, and sharing data (e.g., condition, vehicular, and warning). However, there are existing security and privacy issues with vehicular data, which directly lead to the insufficient utilization of vehicular data. In this article, a blockchain-based lightweight searchable data sharing scheme is presented. Specifically, the proposed protocol achieves efficient data matching and data sharing by uniting the feature of public-key encryption with equality test (PKE-ET) and proxy re-encryption (PRE), meanwhile ensuring reliable matching results by invoking smart contacts. Moreover, a reputation-based dynamic PBFT consensus mechanism is provided. By analyzing the reputation and behavior of the consensus nodes, we further reduce the probability of malicious nodes becoming the consensus nodes, thus decreasing the computing overhead and communication costs in the consensus process. Finally, the security of the proposed protocol is demonstrated based on a computation Diffie-Hellman assumption in the Random Oracle model. According to the performance analysis, it was found that compared to the other protocols, the proposed protocol is computationally lightweight.