An efficient blockchain-based privacy preserving scheme for vehicular social networks

In vehicular social networks (VSNs), edge stations or cloud service provider can support the traffic services or location services to vehicles. Moreover, the information sharing among vehicles can assist vehicles to avoid traffic accidents and guarantee driving safety. However, it is easy to be threatened in the communication of vehicle-to-edge station, vehicle-to-cloud service provider and vehicle-to-vehicle in VSNs, which leads to the vehicle's privacy leakage easily. Besides, some malicious users may provide untrustworthy information to mislead others just for its selfishness. Hence, in this paper, we propose an efficient, reliable and privacy-preserving scheme based on blockchain for VSNs. In our scheme, pseudonym mechanism is employed to achieve individual anonymization by concealing the vehicles' identity. Moreover, to encourage vehicles to report trustworthy information, incentive-punishment mechanism is proposed. Meanwhile, we propose multi-factors and single-factor weight based evaluation mechanism to evaluate the reliability of message. Additionally, Practical Byzantine Fault Tolerance (PBFT) and blockchain are also employed to achieve consensus and store the records respectively, which can prevent malicious entities from manipulating on vehicles' reward scores and credit scores. Finally, we analyze the security of the proposed scheme in terms of external attacks, internal attacks, collusion attacks etc. The relevant experimental results are shown that our scheme is feasible and efficient. (c) 2020 Elsevier Inc. All rights reserved.