Research On Location Cloaking Algorithm Based On P2P System

Nowadays, a larger number of people use location-based service via mobile phones or other mobile devices which have global positioning function. Except for enjoying the provided service, users are also demanding privacy and confidentiality, which are essential to them. The safety of users’ privacy cannot be guaranteed by simply encrypting users’ information. The information of users’location and identification is possibly revealed when they are querying something. Therefore, location cloaking algorithm is one of the most active research issues in the field of privacy protection of location-based service.Location cloaking algorithms make users’ location information both anonymous and misty, which ensure the security of users’ privacy. Majority of the current location cloaking algorithms are adopting centralized structure, under which users would turn anonymous with the help of the central anonymous server. However, the central anonymous server can be easily become the bottleneck of performance and the target of concentrated attack. Recently researchers have proposed to adopt the P2P mode in the location cloaking algorithms, which is able to get rid of the dependence on the central anonymous server and use the known information of neighbor nodes in P2P network to make users anonymous. Nevertheless, currently the proposed algorithms lack of efficiency and security.Through the study of existing location cloaking algorithms, this paper selects to make users’ location information anonymous by employing the information of other users under P2P structure. Such approach would not only satisfy the user’s demand for efficiency, but also ensure users’ privacy security. In regards to the issue mentioned above and two different application scenarios, this paper proposed the Location Cloaking Algorithm based on P2P and Dynamic Grid (the "LCAPDG") and the Location Cloaking Algorithm based on P2P and Static Grid (the "LCAPSG"). Both algorithms conceal the user’s exact location and seek the anonymous areas which meet the privacy requirements via grid ID. In the process of locating, dynamic grid adjusts the area of grid based on the degree of anonymity, the number of users and other factors, and the user’s grid would become the anonymity area accordingly. However, the static grid determines the size of grid disposable, and the anonymity area composed by several different grids. Experiments were conducted to compare the proposed algorithms and the existing algorithms, and demonstrated that the proposed algorithms outweigh the traditional ones in the success rate of anonymity, average anonymous time and average anonymous distance, and prevention "center-of-K-ASR" attack without exposure of accurate location.