Researches On Context-based Location Privacy Protection Middleware In VANET

The Vehicular Ad-hoc Network(VANET)is a new mobile wireless network composed of vehicles and roadside units(RSUs).Between vehicles and vehicles,RSUs and Internet devices,information exchange and sharing are based on proprietary communication protocols and standard data exchange protocols.Due to the heterogeneity of embedded devices,network environments and application software of different vehicles,the development and maintenance costs are both too high.Therefore,the vehicle middleware technology can be introduced between the application system and the underlying equipment to reduce the coupling between hardware and software and improve development efficiency.At present,the continuous development of mobile internet and location technology provides a good development environment for location services,making location services an important part of VANET.When the driver sends a request for obtaining a location service,it is necessary to send the current location of the vehicle user to the RSU,which will result in the leakage of location information,thus causing a safety hazard.This paper designs a context-based location privacy protection middleware(PP-OSGi)for VANET.This middleware meets the advantage of a service-oriented loose coupling of the Open Service Gateway initiative(OSGi)technology framework,so that the vehicle can send a service request to obtain the location service that the service provider issues to the RSU.At the same time,by using VANET network topology changes quickly,vehicle storage space is large,computing resources are abundant,and vehicles can obtain their own and neighbor vehicle context information,etc.,two location privacy protection mechanisms are designed and encapsulated in this middleware to realize the vehicle user's Personalized location privacy protection.In order to solve the privacy leakage problem of vehicle users and their privacy preferences in different contexts,we propose a dynamically adjustable k-anonymity algorithm:Firstly,in the off-line stage,a location privacy preference model is established to predict privacy requirements k of request vehicles in different contexts,which dynamically regulate vehicle users to prioritize service quality or location safety;followed by the online phase,according to the service request vehicle periodically broadcast to obtain neighbor vehicle location information,and to determine whether the distribution is dispersed to meet the satisfaction of anonymous anonymous group,to achieve location privacy protection;Finally,by calculating the central location of hidden vehicles in the anonymous group and the actual query radius,and combining the distance between the vehicle user and service to get the exact query results.Secondly,for areas with low vehicle density in VANET,this paper proposes a location privacy protection algorithm based on dummy location.Firstly,a location privacy preference model is established to predict the privacy requirement k in different contexts;then a candidate dummy location is generated based on the circle division,and then the final k-1dummy location is obtained according to whether the location entropy and the dummy location distribution are dispersed,and the actual calculation is finally obtained.Query the location and query radius to complete the service query.Simulation results show that the designed context-based location protection privacy protection middleware can provide vehicle users with personalized location privacy protection in line with their location privacy preferences,improve location privacy protection,service request success rate and query efficiency,reduce communication costs,while improving the user's driving experience.