The Research Of Security Method For Data Sharing In Internet Of Vehicles Based On Blockchain And Reputation Mechanism

With the rapid development of automobile industry and Internet of Things technology,the concept of Internet of Vehicle（Io V）has been applied.Io V can improve transport efficiency and promote information sharing and cooperation between vehicles,has received increasing attention.For the Io V,it is crucial to prevent internal vehicles from receiving forged information while protecting vehicle privacy from tracking attacks.Most of the existing solutions are based on the centralized architecture,by sacrificing communication overhead or using complex algorithms to ensure information security,resulting in large communication overhead,high latency,vulnerable to attacks and other issues.With the rise of blockchain technology,it has been widely used in smart cities,transportation,data storage and other fields.Its rapid development trend provides a new development idea for the security of the Io V.Aiming at the problems of malicious information interference,privacy leakage,large communication overhead and high delay in the information sharing process of the Io V,this paper conducts the following research based on blockchain technology:（1）Research on information sharing method of the Io V based on blockchainAiming at the requirements of rapid verification of emergency information and privacy protection in the Io V,considering the influence of vehicle recent performance,activity and other factors on vehicle reputation,this paper first proposes a vehicle reputation update algorithm.The algorithm filters the received information twice based on the credibility,and updates the credibility through the feedback of the vehicle for the authenticity of the shared information,so that the malicious behavior of the vehicle can be accurately reflected in the credibility,and the malicious information can be filtered.Secondly,this paper also designed a pseudonym replacement method based on user privacy requirements.This method calculates the pseudonym replacement interval through multiple linear regression equations from the perspectives of road conditions and driver privacy protection requirements,and realizes personalized pseudonym replacement.The experimental results show that the algorithm can effectively improve the security and reliability of information sharing in the Io V.（2）Research on information sharing method of the Io V based on improved PBFTAiming at the low efficiency of non-emergency information consensus in the Io V,which causes low throughput and large communication overhead,this paper proposes an improved consensus algorithm based on PBFT protocol.First of all,this algorithm classifies RSU nodes by defining their reputation accumulation rules and gives them corresponding permissions to reduce the probability of Byzantine nodes participating in the consensus process,thereby increasing the security of the system.Secondly,the algorithm not only optimizes the view switching process by adding alternate nodes,but also redefines the communication rules in the submission stage.The nodes participating in the consensus only need to send commit information to the master node,reducing the number of communication between nodes.The theoretical analysis and experimental results show that the algorithm can reduce the number of Byzantine nodes in the consensus process,improve the throughput of blockchain and reduce network communication overhead.In summary,this paper verifies the emergency information and non-emergency information in the Io V through the vehicle reputation updating algorithm and the improved consensus algorithm based on reputation for PBFT,respectively,to improve the security of shared information in the network.In addition,a personalized pseudonym replacement interval is obtained by a pseudonym replacement method based on user privacy requirements to avoid continuous tracking by attackers.Finally,the full text is summarized and the future research direction is prospected.