Privacy Preserving Reverse Nearest-Neighbor Queries Processing on Road Network

Abstract

In recent years, with the popularity of Location Based Service (LBS) and recommendation system, spatial data query has become a hot study area. Reverse nearest neighbor (RNN) query is one of the most important queries in spatial database. It plays an important role in decision-making system, recommended system and frameworks like so on. In many cases, users do not want to disclose the specific location information to the system. It requires a certain extent anonymous of user information. Compared to the common Euclidean space, Road Network is more practical. However, in previous studies, there is no RNN queries base on road network taking into account the protection of user privacy. In this paper, we propose a novel algorithm- RN-BRNN(Road Network - Bichromatic Reverse Nearest Neighbor) query algorithm, which considering both the road network bichromatic RNN query and user location privacy protection. RN-BRNN algorithm establishes a special Voronoi Cell based on the road network, queried points anonymity, and probability calculus of obtained RNN. Extensive experimental results show that the algorithm maintenances the same time-complexity with the Euclidean space, and improved precision greatly.