Privacy Preserving for Location-Based Services Using Location Transformation

Abstract

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. But 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 (ELPP) 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 performs the mutual transformation between a real location and a pseudo location. Without the transforming parameters, the Anonymizer cannot have any knowledge about a user’s real location. The main merits of our scheme include (1) no fully trusted entities are required; (2) each user can obtain accurate POIs, while preserving location privacy.