Research On Information Privacy Protection In Location-based Service

Location-based services(Location Based Services,LBS)refer to wireless operators using GPS or base station positioning technology to obtain the location information of users,providing users with a variety of value-added services.In recent years,with the rapid development of mobile Internet and the continuous popularity of mobile devices,location-based service applications have been more and more widely used because they can bring great convenience to people's daily life.Users can have access to various positioning services through intelligent devices such as mobile terminals,such as navigation,finding points of interest and nearby friends.However,users often need to submit queries to untrusted LBS service providers when using such services.Because these queries contain personal information,such as the location of the user and the content of interest in the query.If there are untrustworthy service providers or other malicious attackers against location servers to obtain users' location and query information,users will suffer the security threat of location privacy exposure.Therefore,how to provide users with high-quality query services and protect users' privacy is a key issue to be solved in the development of location-based services.In this paper,the following research work is done for location privacy protection:1.Firstly,the location-based privacy protection technology in European space is studied and analyzed,and the system architecture of location privacy protection methods is classified and summarized,and the existing attack methods for location privacy protection schemes are analyzed.2.In terms of the architecture of third-party trusted server,this paper proposes a scheme that combines grid and two-level caching technology.When a user submits a service query request,a square grid area containing user's location is used to send the location of the user to the anonymous server instead of the user's exact location.In the anonymous server,the fixed grid size need to be chosen as the smallest anonymous area.Fixed grids are divided into many smallest fixed grids to improve cache utilization,and quadtree is used to store fixed grids,which speeds up the generation of k anonymous regions.Caching mechanism is introduced in mobile terminals and third-party trusted servers to improve query response speed and user privacy protection.Finally,using experimental comparison and theoretical analysis prove the superiority of the scheme inperformance.3.A location privacy protection scheme based on differential privacy in P2 P mode is proposed.Fixed grids are used to divide the geographic space provided by location servers and stored by quadtree;k anonymous regions are generated by grids in the way of cooperation among multiple mobile users in the P2 P distributed structure;and Laplace noise is added to the centroid location formed by the grid center of anonymous regions by using differential privacy to disturb and prevent background knowledge from attacks;the end of LBS server stores interest point data through R tree to achieve efficient query.Finally,using experimental comparison and theoretical analysis prove the superiority of the scheme in performance.