Research On The Location Privacy Preservation Of VANETs

With the development of intelligent transportation technology,the VANETs,as the important media of the intelligent transportation system,has greatly improved the driver's driving experience.In the VANETs,vehicles are periodically broadcasting information with signs,such as vehicle speed,acceleration,Lane merging information,vehicle location and so on.At the same time,it can receive traffic information from other vehicles which greatly improves the traffic safety of the vehicles.Moreover,vehicles can access Internet network through roadside units,and enjoy Internet services based on vehicle location,such as finding nearest gas stations,finding nearest hospitals,etc.However,when they enjoy the location based services,they usually need to provide their own location to the service provider.If the service provider is not trustworthy,the attacker can get user's location,query content and other information from the service provider,and infer the personal information such as driving route,user habits and habits,so that users' personal privacy is greatly threatened.Therefore,it is of great significance to study the privacy protection of location based services for the popularization and development of the VANETs.We study the location privacy disclosure problem in the use of location based services by the VANETs users,and specifically includes the following work:1.Because of the classical KNN query algorithm: SpaceTwist exists the defects that the query results are around the anchor point distribution and the inaccuracy of query,this paper proposes an improved KNN query algorithm: DATwist,which is based on double anchor points.The DATwist algorithm increases the area of the demand space by increasing the supplementary search anchor points,thereby enlarging the area of the supply space to achieve the purpose of supplementing the missing interest points.Compared with the existing SpaceTwist improved algorithm-HINN,the DATwist algorithm proposed in this paper has better performance than HINN in query efficiency and accuracy,and is more suitable for VANETs environment.2.Due to the existing interest point KNN query algorithm is only suitable for the defect of the snapshot query in the Euclidean space,we introduce the concept of the security region in conjunction with the continuous mobile KNN query requirements under the road network environment.The KNN query results of the vehicle in the safe region will remain unchanged.Then,we propose a security region generation algorithm(VSG)which is based on the vertex of the Voronoi graph unit.In addition,we also verify the security region,and the vehicle users can verify the authenticity of the security region according to the received authentication targets.After that,we optimized the performance of VSG validation.And through the comparison experiment with the existing algorithm BUF/BUF*,the VSG has some advantages in communication cost and computing overhead.Based on the research of the existing LBS(Location-based Service)protection technology,combined with the characteristics of the communication structure of the VANETs,we propose a LBS privacy protection framework for VANETs.Then,we propose an improved DATwist algorithm based on the existing SpaceTwist algorithm to make the finding of the interest points more evenly distributed.For the continuous query problem in the road network environment,we propose a VSG algorithm which is based on Voronoi graph cell vertex.The algorithm can provide DATwist with a safe region under the road network environment,enabling the VANETs users to continuously move KNN queries through DATwist.The performance analysis and comparison experiments show that our scheme can effectively protect the personal location privacy of the vehicle users.