Enhanced Location Privacy Preserving Scheme in Location-Based Services

With the increasing popularity of mobile communication devices loaded with positioning capabilities (e.g., GPS), there is growing demand for enjoying location-based services (LBSs). An important problem in LBSs is the disclosure of a user's real location while interacting with the location service provider (LSP). To address this issue, existing solutions generally introduce a trusted Anonymizer between the users and the LSP. However, the introduction of an Anonymizer actually transfers the security risks from the LSP to the Anonymizer. Once the Anonymizer is compromised, it may put the user information in jeopardy. In this paper, we propose an enhanced-location-privacy-preserving scheme for the LBS environment. Our scheme employs an entity, termed Function Generator, to distribute the spatial transformation parameters periodically, with which the users and the LSP can perform the mutual transformation between a real location and a pseudolocation. Without the transforming parameters, the Anonymizer cannot have any knowledge about a user's real location. The main merits of our scheme include the following: 1) no fully trusted entities are required, and 2) each user can obtain accurate points of interest while preserving location privacy. The efficiency and effectiveness of the proposed scheme are validated by extensive experiments. The experimental results show that the proposed scheme preserves location privacy at low computational and communication cost.