Research On Mobile User Location Privacy Protection Based On Location Service

With the rapid development of the mobile Internet technology, mobile users are paying more and more attention to location-based service(LBS). LBS can provide valuable services to mobile users based on the user's location information, which greatly benefit the user's work and life. However,the user needs to send his current location to obtain the service, which may cause the leakage of his location information. Using a imprecise location is an effective way to protect the user's location privacy. For example, we can use a region to replace a real location. When processing continuous query, the user needs to send the current area to the server continuously and the attacker may infer the user's real location through the overlapping regions. So, how to protect the user's location privacy in the continuous query is a hot topic. This paper deeply studies the location privacy protection problem in LBS and uses a centralized framework consisting of client, trusted anonymous server and LBS server for privacy protection. Our main tasks are as follows:(1) To avoid the overlapping region attack when a mobile user request for continuously queries,we propose a method of avoiding overlapping circle attack for anonymous server, which can protect the user's location privacy by changing the parameters requested by the user. Then we propose a query processing algorithm EPPINQ for LBS server, which combine depth first search and the minimum maximum distance to the query point. Finally, we design experiments to verify our two algorithms. Results show that avoid overlapping circle attack algorithm can protect use's location privacy better and EPPINQ can query more effectively.(2) A query algorithm is proposed for the anonymous server to filter the query results because the anonymous server needs to refine the candidate result set. After the avoid overlapping circle attack algorithm, we propose a query algorithm for the anonymous server. The proposed algorithm extends the existing query algorithm so that the anonymous server can find the suitable result quickly according to the user's request. Then the algorithm is applied to Baidu Map and the results show that the extended algorithm is feasible with high efficiency.