Research On Location Privacy Protection Based On Nearest Neighbor Query In Mobile Internet

With the rapid development of the mobile Internet,the traditional Internet has been replaced in many aspects.The location based service(LBS)has been widely used and is one of the mainstream services under the current mobile Internet.People can use the LBS service to easily and efficiently obtain location services according to their own needs,such as location navigation,travel route development,point of interest search and stranger socialization.However,nothing interesting,as we know,is ever completely one-sided.While locationbased services bring convenience to people,it also causes a potential threat to users' privacy.While the server proving the corresponding service,it is needed for the user to upload his or her location information.If the location information of the user is not well protected,the attacker will obtain the location information of the user and many other sensitive information may also be exposed,such as home address,work company,health status,spending habits and so on.In view of the above considerations,this paper proposes a related location privacy protection scheme for the k nearest neighbor query problem in location services.In the k nearest neighbor query,user want to search for the related information about the nearest k points of interest nearby.We mainly focus on how to protect the user's location privacy efficiently without degrading the service quality.The main contents of the study are as follows:Firstly,a location privacy protection method based on anonymous space for k nearest neighbor queries is proposed.We use the virtual space mapping curve and the Voronoi diagram to propose a scheme for k nearest interest point queries based on the pseudo location of the user and the point of interest.Our solution mainly solves the problem that the space division using the Hilbert curve can still be successfully attacked by the attacker.By selecting different spatial mapping curves and the randomness of the eigenvalues in the mapped curve cells,there is still a lot of difficulty in successful attacks for the malicious attacker,even they already get the relevant background knowledge.Secondly,a location privacy protection method based on cryptography for k nearest neighbor queries is proposed.We introduced a third-party cloud server.With its powerful storage and computing power,the location server data and user's location data are encrypted and uploaded to the cloud server for processing and calculation.Our solution mainly improves the security k nearest neighbor search algorithm in the existing scheme,so that it can resist the attack of a higher level of malicious attackers.Even if the attacker has mastered more relevant background knowledge,there is still a greater difficulty in cracking ciphertext.