Research On Privacy Protection Of Vehicular Ad Hoc Network Based On Blockchain

In the 21 st century,the number of automobiles in our country has soared.Intelligent transportation system(ITS)plays an increasingly important role in people’s daily life.As an important part of ITS,VANETs provides technical support for people’s Intelligent Transportation.There are still some problems.A large number of data are generated along with during vehicle interaction.This type of data,including the private data,is vulnerable to malicious destruction and illegal access by attackers,it will lead to privacy leak as user’s true identity,living habits and other information.This paper focuses on the privacy protection of VANETs:First,a block chain-based group signature scheme for VANETS is proposed.Blockchain is introduced to solve the problem that the communication between nodes in VANETS model requires a trusted third party.A group signature scheme based on verifier local revocation is designed,so that the verification cost will not increase due to the growth of the Certificate revocation list.At the same time,different treatments are carried out according to different reasons for node retraction in the scheme to prevent the rejoining of malicious nodes.Finally,the correctness,security and performance of the group signature scheme are proved.Secondly,an improved consensus algorithm based on blockchain for VANETs model is proposed.Aiming at the problem of dishonest nodes in the network to intervene in the entire network to achieve consensus,Practical Byzantine Fault Tolerance is proposed,which includes Credit system and distance algorithm,it can complete delete dishonest nodes.Credit system divides nodes into waiting nodes and penalty nodes.When consensus is needed,a certain number of nodes will be selected as consensus nodes in the waiting nodes.it can lead to ensure that the system is consensus by honest nodes most of the time.The distance algorithm can effectively reduce the physical distance between consensus node and it also can decrease the time required for the consensus.Finally,the performance of the scheme is analyzed by mathematical reasoning and experimental comparison.