A Hierarchical Blockchain Framework with Selectable Consensus Scope for Data Sharing in Internet of Vehicles

With the development of Internet of Vehicles (IoVs), data sharing has become a crucial means to improve driving safety and travel efficiency. In the process of data sharing, ensuring the security of the sharing process is of paramount importance. Using blockchain technology to ensure the security of data sharing in vehicular networking scenarios is a promising approach. However, there are some issues in applying blockchain to data sharing in vehicular networking scenarios. On the one hand, the consensus of blockchain requires multiple full network broadcasts, and as the number of nodes in the network increases, system overhead will grow rapidly. On the other hand, malicious nodes in blockchain may affect system security. To address these problems, we propose a hierarchical blockchain framework with selectable consensus scope. We dynamically select the consensus scope of data according to its impact range, avoiding consensus on the entire network. In addition, we propose a trust model to compute the reliability of Roadside units (RSUs) in the area, assigning different permissions to different RSUs in the system. We also improve the PBFT algorithm based on this reputation model, further reducing the cost of consensus. Simulation results show that the proposed approach can reduce consensus consumption and identify malicious nodes more quickly, ensuring the efficiency and security of the data sharing process.