Research On Efficiency And Precision Adjustable Mechanism In Location Privacy Preserving Query

With the development and popularization of mobile networks and spatial positioning technology, location-based service (LBS) plays an increasingly important role in mobile applications. With the increasing concerning to individual privacy, privacy protection in location based services becomes a hot topic in the domain of database research. At the same time, how to provide high-quality service and guarantee privacy becomes a related hot topic. Existing work usually lacks of concern for users’s preference. For example people are usually willing to get adjustable function for query accuracy and efficiency. So this paper concerntrates on users’s preference for accuracy and efficiency, proposing adjusted method for LBS service. The main contributions are summarized as follows:(1) Most of current work in privacy preserving location based k nearest neighbor query on road networks in common falls short in ignoring user’s preferred adjusting requirement in relation to query accuracy and query efficiency. Definition of adjacent POI and probability distribution of POI are introduced and the method of constructing probability distribution of POI is proposed for statistic. Based on the aforementioned definitions and scheme, an adjustable privacy-preserving k nearest neighbor query method AdPriQuery is proposed, which provides query users the function to seek trade-off between query efficiency and query accuracy by adjusting the parameter of probability threshold.(2) To provide high-quality service in continuous location based service (LBS) query in road network, a method to generate k-nearest-neighbours (kNN) points of interest(POI) safe region is proposed. In advanced, an adjustable safe region generating algorithm is proposed to support user’s preference for query accuracy and efficiency.(3) Design experiment to prove the feasibility of algorithms besides theoretical analysis. Result of the experiment shows AdPriQuery provides query users the function to seek trade-off between query efficiency and query accuracy. KSR reduces number of times building connections between client and server while providing better service quality. AdkSR support users’ preference for query efficiency and accuracy well.