The Research Of Blockchain-Based Vehicular Ad Hoc Network Technology

As a typical application of MANET(Mobile Ad Hoc Network),VANET(Vehicular Ad Hoc Network)is one of the most promising applications in ITS(intelligent transportation system),which aims to provide road condition warning and data self-organization transmission capacity for vehicles on the road.VANET can make full use of the large amount of data shared by vehicles and transportation infrastructure,greatly improves driving safety and traffic control conditions.However,when vehicles share data in the network,they face issues of identity privacy leakage and low message reliability.At the same time,forwarding information requires resource consumption,so vehicles usually choose selfish behaviors to maximize their own interests and refuse to participate in the conversation.It is necessary to introduce a reward and punishment mechanism to encourage vehicle cooperation.When perform data storage and calculation in a centralized server,it has the disadvantages of high maintenance costs and susceptibility to single-point attacks.Distributed solutions can be used for efficient control.This thesis constructs a secure and trusted incentive sharing distributed architecture based on blockchain in VANET,including the anonymous privacy protection mechanism,the vehicle credible management mechanism,and the blockchain-based token incentive mechanism.Firstly,in the privacy protection mechanism,we introduce the threshold ring signature technology to avoid the vehicle’s identity leakage,and use the EC-ELGamal asymmetric encryption algorithm to reduce the risk of data attack and hijacking.Secondly,in the credibility management mechanism,we establish a management model for updating the reputation value of vehicles,and use the logistic regression algorithm to calculate a fair and reliable reputation value,in which added the malicious flag to consider the current situation and historical factors comprehensively.We also design a message authenticity judgment mechanism,where introduces the MAD statistics to filter abnormal opinions.In addition,we propose a blockchain-based incentive mechanism to grant a certain amount of token rewards to vehicles participating in effective conversations,and to encourage vehicles to share the real-time traffic information actively.We adopt a hybrid consensus mechanism of PoW and PBFT to balance the efficiency and the authenticity of transactions.We use Veins,a vehicle simulation platform based on OMNeT++ and SUMO,to verify the effectiveness of the model.Experimental results show that the method proposed in this thesis not only meets the requirements of security and privacy,effectively resists various malicious attacks and hidden dangers of privacy leakage,but also encrypts signed session data,determines the authenticity of messages,reaches consensus and tracks malicious vehicles in VANET.