Research On Anonymous Authentication And Identification Mechanism For VANETs

As a product of the intelligent transportation development,vehicular ad hoc network(VANET)has attracted extensive attention in recent years.VANET can realize the realtime sharing of traffic information through communication between vehicular unit and roadside unit,which plays an important role in reducing casualties,optimizing traffic distribution and improving traffic efficiency.It is important to study the security of VANET.Although some significant progresses have been made in VANET security,there are a series of challenges with the increasing of vehicles.On the one hand,the pseudonym management is a serious problem in anonymous authentication.Vehicle communication applications use security information such as vehicle identity and location,so the privacy of vehicle is easy to be leaked.In order to solve the problem of privacy leakage in VANET,vehicles use pseudonyms to achieve conditional privacy protection.The management of pseudonyms becomes a new challenge with increasing of the pseudonyms number.However,the existing schemes used PKI technology to realize pseudonyms management due to some limitation of PKI technology.On the other hand,there is the problem of time delay in the process of signature identification.In VANET,vehicles transfer driving-related messages to roadside units.In order to ensure the integrity of messages,vehicles use digital signature technology to sign each message before the message is sent.Since a large of time delay occur in the signature verification and invalid signature identification process,the low efficiency of the computing capability of the existing VANET cannot guarantee the quality of service.Focusing on the above problems,we made some progress as follows:(1)To propose an automatic management scheme of vehicle pseudonyms based on blockchain,which can realize automatic registration,update and revocation of vehicle pseudonyms by using smart contract.At the same time,the voting system is applied to the pseudonym revocation protocol to solve the problem that some legal vehicles would be wrongly revoked pseudonym.The security analysis shows that the proposed scheme can effectively resist internal and external attacks,and meet the security requirements of VANET.The performance is analyzed through experiments and simulations.After the number of vehicles exceeds 5000,the total cost of managing vehicles is less than half of the cost of public key infrastructure.The experimental results show that the automatic pseudonym management scheme is practical and superior to the existing schemes in terms of storage and computational overhead.(2)To present a small-batch verification and identification scheme that can speed up the signature verification and the invalid signature identification.In the proposed scheme,according to the signature number and the historical signature error rate,we first build an optimization model,which transforms the problem how to divide a batch of signatures into several appropriate small-batches into an integer programming problem,and then store the optimal batch solution table in roadside units.Moreover,in view of the current task,RSUs can automatically divide a batch of signatures into several appropriate small-batches.Any invalid signature in these small-batches can be quickly identified by using of the exponentiation method.By comparison with the existing schemes,the total time delay is reduced to 50% in optimal circumstances.Simulation results show that the proposed scheme can achieve fast signature verification and invalid signature identification.