Blockchain-based multimedia sharing in vehicular social networks with privacy protection

The rapid development of the vehicular ad-hoc network (VANET) promotes the development of vehicle electronics, networking, and intelligence. In addition, each vehicle can establish social relationships with others freely in vehicular social networks (VSNs). Multimedia also plays an important entity in vehicles' data sharing. However, VSNs are still in the early stage of development, and it may bring many security challenges in the process of sharing multimedia data. Both the users' and vehicles' privacy may be leaked, and users' communication habits are easy to be analyzed by adversaries. In addition, the shared multimedia data are more likely to be maliciously tampered with or forged. In this paper, we propose a privacy-preserving scheme based on blockchain for multimedia data sharing in VSNs. We use cryptographical primitives to hide the real identity of users, vehicles and RSUs. At the same time, we use blockchain to ensure reliable data sources and keep attackers from tampering or forging multimedia data. Finally, the feasibility of our scheme is proved by theoretical security analysis and comprehensive experimental evaluation.