Joint Differentially Private Gale–Shapley Mechanisms for Location Privacy Protection in Mobile Traffic Offloading Systems
Yuan Zhang, Yunlong Mao, Sheng Zhong · IEEE Journal on Selected Areas in Communications · 2016
Being an important application of spectrum sharing in cellular networks, mobile traffic offloading, which advocates third-party owners of network resource on unlicensed/licensed spectrum to share their spectrum and provide data offloading services, is considered a promising solution to severe spectrum shortage faced by cellular network service providers. In this paper, we consider a general mobile traffic offloading system that adopts the widely used Gale-Shapley algorithm to optimize its mobile phone users (MUs) to offloading stations allocation plan. We notice that without careful protection, such a system could cause serious threat to MUs' location privacy, and thus design effective countermeasures based on the powerful state-of-the-art differential privacy concept. Specifically, we have proposed two joint differentially private Gale-Shapley mechanisms with strong privacy protections for mobile traffic offloading systems. The first mechanism is able to protect each user's location privacy even when all other users collude against this user assuming the system administrator can be trusted. The second mechanism is able to achieve the same privacy guarantee against colluding users, and moreover against an untrusted semi-honest system administrator. We perform extensive experiments to evaluate our mechanisms, and the results show that our mechanisms have good efficiency, accuracy, and privacy protection.