Protecting Location Privacy Using Cloaking Subgraphs on Road Network

Mobile users traveling over roads often issue KNN queries based on their current locations with their mobile terminals (e.g. where is the nearest gas station?). However, exact location information transmitted to an unsecure server will easily lead the mobile user to be tracked. Thus it is important to protect mobile users' location privacy while providing location-based services. People traveling over roads always follow a road network. We observe that two cloaking subgraph structures, which we name cloaking cycle and cloaking tree, can be used to protect mobile users' location privacy effectively in road network environment. Based on these two subgraph structures, we propose a novel location privacy preserving approach using cloaking cycle and forest, which can effectively protect mobile users' location privacy while efficiently providing exact location-based services.