| The Internet of Vehicles(i.e.,Io V)is a new industrial form of deep integration of automotive,electronics,information communication and traffic management industries.As the mainstream of automotive electronics today,it has become an important symbol of the future smart city.However,as more and more intelligent devices are connected to Io V,the data security of Io V has attracted great attention from the whole society.Malicious vehicles may transmit false information in the network for their own interests,mislead vehicles to make wrong responses,and pose a serious threat to system reliability and traffic safety.Distributed consensus algorithm can realize the rapid update of vehicle data and the rapid consensus of Io V system,which helps to coordinate the actions of vehicles and makes consistent decisions.Based on the Byzantine fault-tolerant mechanism,this thesis designs two different data consensus algorithms for Io V,and the concrete research content and contributions are as follows:Io V environment is changeable,and malicious vehicles may show wrong behavior and broadcast false data information at any point in time.Considering that the Practical Byzantine Fault Tolerant consensus algorithm can not only support fault-tolerant fault nodes,but also support fault-tolerant malicious nodes.Combining it with Io V,a Byzantine Fault Tolerant Consensus Algorithm based on Proof-of-Eligibility has been designed,which can ensure that vehicles reach consensus on data information.Furthermore,in order to ensure the true correlation between vehicles and data information,only vehicles that correctly solve the puzzle are qualified to participate in the consensus process through Proof-of-Eligibility,which prevents malicious vehicles and unrelated vehicles outside the event area and ensures the safety of the consensus group.Meanwhile,through the certification and evaluation stage,the group membership list and the evaluation opinion list are agreed respectively to ensure the correctness of data information.Simulation experiments show that the consensus algorithm can guarantee correct consensus results when the proportion of malicious vehicles is less than 1/3,which demonstrates the effectiveness and accuracy of the algorithm.In addition,considering that the communication complexity of the Practical Byzantine Fault Tolerant Consensus Algorithm reachesO(n ~2),it leads to poor scalability for a large-scale Io V network.A Byzantine Fault Tolerant Consensus Algorithm based on Threshold Signature is proposed,which reduces the communication complexity to O(n).Firstly,the vehicle with the highest reputation values is set as the master node and broadcasts event information.Each vehicle uses credibility detection to verify the information.By using RSA-based(k,n)threshold signatures,k vehicles are allowed to generate signature shares.The master node combines verification of signed shares.Meanwhile,the multi-weight reputation update scheme evaluates the honesty of the master node,which is used to distinguish normal vehicles and malicious vehicles.Simulation experiments show that the algorithm greatly reduces the communication complexity at the cost of sacrificing the accuracy of a few consensus results,and effectively shortens the consensus time and has good scalability. |
