Research On Query Efficiency And Privacy Security Adjustable Mechanism In Location Privacy Preserving Query

With the rapid development of wireless communication technologies and mobile devices, Location-based Services have attracted widespread attention. As the basic operation of Location-based Services, neighbor query has been wideky studied. However the convenience LBS brings to people’s lives, LBS also makes the users’ privacy security suffers threats. Individual location privacy protection makes the privacy protection service become a hot research topic in recent years. Most researches focused on the location privacy protection strength or query efficiency while ignoring the preference of the strength of location privacy protection and query efficiency. Personalized regulation of the strength of location privacy protection and neighbor query efficiency in location privacy protection neighbor query becomes one of the important problems need to be solved in practical application.Main work of this paper is as follows:1) In view of location privacy leakage problem because of the ignorance of users’location distribution when contracting anonymous road subnet, use the theory of entropy to define the concept of user location probability distribution and build (k,l,d) privacy protection model, based on which the location privacy and query efficiency control algorithm is put forward.2) In view of the low efficency problem because of the periodically communication between client and the server in continuous query, put forward the concept of k nearest neighbors safe region of road network and use the centrifugal segments count to constraint the calculation of safe region, so that to regulate between location privacy and overall query efficiency.3) Use pre-computed first-order Voronoi diagram in k nearest neighbors query for the high cost of computing k order Voronoi graph for varying values of k. Then build the biggest mobile area by builing k order Voronoi diagram of local POIs and obtain a good control in the location privacy security, query efficiency and query accuracy.Theoretical analysis and experimental results show that the proposed methods can realize overall regulation between location privacy security and query efficiency on the basis of location privacy preservation.