A cooperative method for privacy preservation in real-time location monitoring services

This paper explores the problem of preserving location privacy in real-time location monitoring services. Because monitoring personal locations with untrusted service providers may breach monitored individuals' privacy, we adopt the system model that depends on a trusted anonymizer. The main role of the anonymizer is to blur individuals' locations into the cloaking regions for providing location k-anonymity to them. Most existing methods assume that the monitored individuals continually communicate with the anonymizer to report their current locations, and the anonymizer periodically regenerate their cloaking regions. However, this degrades the system performance due to the increased workload at the anonymizer as well as the severe communication bottleneck. With this problem in mind, we propose a distributed and cooperative privacy-preserving method, which leverages the computing capabilities of individuals' handheld devices in order to provide privacy guarantee (i.e., location k-anonymity) for the individuals in an efficient manner in terms of the workload at the anonymizer and the communication cost. The basic idea is to make the anonymizer and the individuals share the process of generating and keeping up-to-date cloaking regions. Through a series of simulations, we verify the efficiency of our work.