Research On Location Privacy Protection Method Based On Continuous Query

With the wide application of location sensing technology such as satellite positioning system,WIFI and sensor,as well as the development of Location Based Services(LBS),the collection of personal location data is increasing,and the protection of location privacy is paid great attention.Based on LBS,users are required to report the location information of users to servers that may not be trusted continuously,so as to obtain services according to their location,which will cause the disclosure of personal location information.Through the combination of these data and other available information,personal sensitive information is inferred,which leads to the risk of privacy disclosure.For continuous queries where users report their location regularly,attackers can infer more information about user privacy by analyzing user snapshot queries.Because the traditional Euclidean space location privacy protection solution does not understand the network topology characteristics,it is difficult to apply to the road network environment.In view of the location privacy problems in continuous location service,this paper starts from three aspects: query privacy,location privacy and semantic location privacy in order to provide personalized location privacy protection for users.Aiming at some problems existing in location privacy,the traditional privacy protection methods are improved and corresponding solutions are put forward,Therefore,the goal of protecting user privacy is achieved.In order to solve the problem of the heavy workload of LBS server and the long waiting time of mobile users in continuous nearest-neighbor(NN)queries,this paper proposes a continuous NN query cache solution based on the third-party trusted anonymous server to protect the location privacy in the continuous LBS.For NN query,an algorithm is proposed to accelerate the growth of effective location region;make anonymous server build effective location area,and combine the proposed virtual selection algorithm to further protect the privacy of users.The performance is evaluated by experiments;The experimental results show that this method is obviously superior to the existing methods based on the third party trusted anonymous server,improves the cache hit rate,reduces the server load,and can effectively protect the user's location privacy.Then,in view of the problem of user sensitive semantic leakage caused by the continuous query location request service without considering semantic information,a privacy protection algorithm is proposed to protect the user semantics and location continuous query road network services.That is,offline trajectory clustering algorithm and semantic location map are used to hide users' choice,realize the protection of query privacy,location privacy and semantic location privacy of the client on the road network,and effectively protect the absolute privacy of the client.The experiments are carried out on SUMO simulation platform.The experimental results show that the performance of the algorithm is better than that of other existing algorithms,and the effectiveness of the algorithm is verified.