PEPPeR: A Querier's Privacy Enhancing Protocol for PaRticipatory Sensing

In this work we study the problem of querier privacy in the Participatory Sensing domain. While prior work has attempted to protect the privacy of people contributing sensing data from their mobile phones, little or no work has focused on the problem of querier privacy. Motivated by a novel communication model in which clients may directly query participatory sensing networks operated by potentially untrusted adversaries, we propose PEPPeR, a protocol for privacy-preserving access control in participatory sensing applications that focuses on the privacy of the querier. Contrary to past solutions, PEPPeR enables queriers to have access to the data provided by participating users without placing any trust in third parties or reducing the scope of queries. Additionally, our approach naturally extends the traditional pull/push models of participatory sensing and integrates nicely with mobile social networks, a new breed of sensing which combines mobile sensor devices with personal sensing environments.