Road Network-Aware Anonymization in Mobile Systems with Reciprocity Support

Most existing solutions on location anonymization fail to address the issue of location privacy protection for mobile users traveling on road networks. In this paper, we present a road network-aware privacy model to handle the location privacy problem in mobile systems. We present third party supported anonymization which can be plugged into existing mobile systems without major modifications. As opposed to current road network specific solutions, our system has the following salient features. First, we argue that the graph density of a cloaked subgraph is an important location cloaking quality measure for road network-based location privacy protection. High graph density leads to high utility of the cloaked location with respect to spatial resolution. Second, we devise a suite of graph-based cloaking algorithms which guarantee reciprocity - an important location cloaking property that many existing approaches fail to support - under an enhanced privacy model. Further, we use controlled randomization in the cloaking process to provide higher privacy strength while maintaining the utility of the cloaked location. Last but not the least, our experimental evaluation shows the efficiency and robustness of the approach in terms of privacy, utility and performance of the model.