Enhancing Location Privacy through User-Defined Grid in Location-Based Services

With the increasing popularity of location-based services (LBSs), the concerns for location privacy have also been growing. To address this issue, existing solutions generally introduce a fully-trusted third party between the users and the location service provider (LSP). However, the fully-trusted third party offers limited privacy guarantees and incurs high communication overhead. Once the fully-trusted third party is compromised, it may put the user information in jeopardy. In this paper, we propose an enhanced location privacy-preserving scheme through the user-defined grid in LBSs. Our scheme adopts Order-Preserving Symmetric Encryption (OPSE) and K-anonymity technology, and combines with the user-defined grid to improve the user's location privacy. The anonymizer does not have any knowledge about a user's real location, and it can only implement simple comparison and matching operations. The security analysis proves that our proposal can protect user's location privacy effectively.