Research Of Privacy Preserving Mechanism In Vehicular Ad Hoc Network

As an important support of Intelligent Transportation Systems(ITSs),VANET has greatly promoted the developments of transportation and facilitated people's lives.According to VANET,drivers can not only get real-time traffic information(e.g.lane merging,congestion avoidance,detour notification,road conditions,emergency events),but also value-added services that enhances driving experience(e.g.navigation,toll payment services).However,due to the openness of services,VANET has brought a lot of security and privacy problems.On the one hand,a time-critical message can be forged,modified and discarded by malicious vehicles,severe consequences will be the result.On the other hand,through the observation and tracking of the target vehicle's position,driving route and other information,the malicious vehicle can steal the driver's privacy information such as the identity and habits so as to commit crimes.Therefore,it is of great significance to study the privacy protection of VANET for large-scale application.First,based on the anonymous authentication and performance requirements,this paper proposed an identity-based anonymous authentication scheme.The problem of uneven density of RSUs deployments in real life is fully considered in the scheme.On the one hand,the vehicle can request the short-time certificates to the neighbor RSU.On the other hand,when there is no RSU nearby or a case where the short-term certificate is insufficient,the vehicle carries out communication using the pseudonym certificate carried itself.In this way,it will not only greatly reduce the storage cost of the traditional pseudonym scheme,but also improve RSU service capabilities of the distributed management scheme.This scheme can also achieve condition privacy protection.Through the cooperation of trusted authority and RSU,this scheme can find out the true identity of the malicious vehicle.Finally,through the experimental analysis and simulation evaluation,the scheme proposed in this paper has better performance advantage in identity-based privacy protection and performance overhead compared with the previously proposed scheme.Next,Based on the location privacy protection,this paper proposes a dynamic group-based mix-zone for location privacy protection.Because of the fixed mix-zones lack of flexibility,the scheme in this paper can establish mix-zones dynamically at any time and location based on the group.In addition,in order to reduce the number of pseudonym changing,it is permissible to join the group only if the period of pseudonym is to be expired.When the number of pseudonym changing requests reaches the privacy protection requirement,the group leader applies for the establishment of mix-zone to the neighboring server on behalf of the group members.In this way,it can reduce data redundancy and delay.Finally,through the performance analysis and simulation evaluation,the scheme proposed in this paper has a good advantage in the anonymous set entropy,the probability of successfully tracking the target vehicle,the processing time.The simulation results show that the privacy preserving mechanism proposed in this paper is more excellent in identity privacy protection and location privacy protection.And it has a good reference value for the wide deployment and application of VANET.