Abstract: Enjoying the location-based service (LBS), the mobile subscribers may threaten the disclosure of location privacy. To protect location privacy, an effective method for location privacy preserving was proposed to cloak the user's exact coordinates into a spatial region and turn the location-based query into region-based query. Existing continuous nearest-neighbor query algorithms with privacy-aware are based on snapshot, which incur higher central processing unit (CPU) cost. The location privacy-based continuous nearest-neighbor query was studied and an algorithm named reusing-based location privacy-preserving continuous nearest-neighbor query (RLPCNN) which is based on reusing technique query updating was proposed. The algorithm can reduce the cost of computation by using the similarity between the two adjacent time and make the answer set updated quickly, which can quicken the response time markedly. The experiments show that the algorithm is effective and efficient.

Key words: location-based service, location privacy, nearest-neighbor query, continuous query, reusing technique