How to protect query and report privacy without sacrificing service quality in participatory sensing

The ubiquity of mobile devices has brought forth the concept of participatory sensing, whereby people can collect and share data from ambient environment for the benefit of themselves or community. To encourage participation of all stakeholders and guarantee system functionality, a privacy-preserving participatory sensing system should be established to hide querier's and participant's sensitive information(e.g., interest, location and content). Meanwhile, it is also imperative for server to provide an accurate and quick service(match the need with supply and retrieve the desired result from collected data set) for queriers when queries and reports are encrypted to protect privacy. In this paper, we propose Query and Report privacy-preserving protocol(QueRe) in participatory sensing system aiming to protect the query privacy and report privacy without sacrificing the service quality. Security analysis and performance simulation show our method achieves superior performance in privacy protection and service quality. To the best of our knowledge, our work is first attempt for protecting query privacy and report privacy while considering server's service quality.