HCSC: A Hierarchical Certificate Service Chain Based on Reputation for VANETs

In vehicular ad hoc networks (VANETs), there are many resource constrained communication nodes, distributed geographical locations, and low delay requirements. The authentication system is required to be distributed. However, the information interaction between traditional distributed authentication entities (AEs) is not transparent, and the use of blockchain is only to save certificate status records on the chain. There is a lack of trusted security management mechanisms between AEs, so there is a risk of collusion attacks and behavior record forgery and tamper attacks between AEs. Therefore, this paper mainly addresses the management problems of opaque interaction and insufficient security verification of distributed authentication entities in the VANETs scenario. In this paper, based on the security features of blockchain technology, such as public audit and tamper proof block structure, and distributed trust consensus, we propose a hierarchical and trust certificate service chain based on reputation value called HCSC. We have a set of safe and reliable management mechanisms between distributed authentication entities such as the Bitcoin system. First, we integrate the traditional hierarchical authentication system and the blockchain network into a new hierarchical certificate service chain. Then, we propose a reputation evaluation model based on the logistic regression model by quantifying the behavior records of the AEs. In addition, a new hierarchical reputation consensus based on delegated proof of stake (DPoS) and proof of work (PoW) is given. Then, a fast verification based on block height and security verification for the efficiency and security of certificate verification is proposed. Finally, the security analysis is given, and a prototype implementation of HCSC is developed based on Fabric. The experimental simulation and security analysis reveal that the HCSC is very efficient and suitable for the above issues.