Location Privacy-Aware Nearest-Neighbor Query with Complex Cloaked Regions

Abstract

The development of location-based services has spread over many aspects of modern social life. This development brings not only conveniences to users' daily life but also great concerns about users' location privacy. In such services, location privacy aware query processing that handles cloaked regions is becoming an essential part in preserving user privacy. However, the state-of-the-art cloaked-region-based query processors only focus on handling rectangular regions, while lacking an efficient and scalable algorithm for other complex region shapes. Motivated by that problem, we introduce enhancements and additional components to the location privacy aware nearest-neighbor query processor that provides efficient processing of complex polygonal and circular cloaked regions, namely the Vertices Reduction Paradigm and the Group Execution Agent. We also provide a new tuning parameter to achieve trade-off between answer optimality and system scalability. Experiments show that our query processing algorithm outperforms previous works, in terms of processing time and system scalability.