Research On The Privacy Preservation For VANETS

VANETs is a kind of Mobile Ad Hoc Network that emerges recent years. It can ef-fectively improve transportation safety and driver environment. However, due to the large scale of network, openness of the wireless communication channel and easy tracking of mo-bile vehicles, VANETs is prone to attack of safety and leakage of privacy. The adversaries may intercept the messages diffused in the wireless channel, analyze the data, predict the trajectories and track the vehicles. If any privacy information of the vehicles is leaked out in VANETs, VANETs thereof can’t be widely accepted by the public. Therefore, some indis-pensable privacy-preserving for vehicles is a prerequisite for people to accept the VANETs.Through systematic analysis the issues of security threats and privacy needs in VANET-s, summarizes two main privacy issues including identity privacy and location privacy in VANETs. Analysis the details for the privacy issues under the different scenarios. And dis-cuss respectively from four aspects including secure vehicle communication, secure Internet access, batch verification and secure LBS. And given the corresponding resolution.For anonymously communication in VANETs, we propose an anonymous authentica-tion protocol. It adapts the ring signature and identity based encryption to authenticate the communications between vehicles. By its inherent safety feature, such as anonymity and spontaneity of the ring signature, it is very suitable for the communications in VANETs. But how to form a common ring with the nearby ones when the vehicles are moving and sign the message by adapting this ring usually is a hard problem. For this problem, we have designed two schemes for forming the ring. They are respectively online aid from the RSU and coordination between the vehicles. And our scheme can efficiently solve the problem of ring formation.Vehicles can access the Internet by through the VANETs, Some former schemes usually only care of access control and thus ignore the privacy preserving of the users. For this issue, we propose an access control protocol for privacy for Internet access in VANETs. In our scheme, the visitor first registers in the Trust Authority, and get a pseudo identity. The vehicle uses this pseudo identity to apply some service from the service provider and thus gets a token for access. When access to the service, the token can be used for validation. When the session begins, by applying the symmetric encryption of the session content and changing the session symbol and encryption key in the session, it can be difficult for relating a session with some vehicle and correlating two different sessions to the same vehicle.We make a cryptographic analysis about the Zhang et al scheme, and found some secu-rity vulnerabilities. Then, we propose a improved batch verification scheme for VANETs. In our scheme, each vehicle obtains a root certificate from CA, then it can generate certificate by itself and authenticate the messages anonymously. Every vehicle can batch verification for received message.The vehicle through share location information with third-party to obtain location-based services in VANETs, this may result in disclosure of user privacy information. We propose a privacy preserving scheme for location-based service based on the general LBS architecture. We remove the trusted third party from the architecture for make it suitable for VANETs.