B-Mobishare: Privacy-Preserving Location Sharing Mechanism in Mobile Online Social Networks

In recent years, mobile Online Social Networks (mOSNs) have gained more and more popularity. Compared with traditional social networks, mOSNs allow user´s location to come into play. Thus, location sharing becomes a fundamental component of mOSNs, and many opportunities for location-based services arise which have a high value for the users. At the same time, the need to share location information inevitably leads to significant privacy concerns. Recently, Wei et al. Proposed the Mobishare mechanism to enable flexible location sharing between trusted social relations. In this paper, we make a further research on privacy-preserving location sharing on mOSNs. We note that only the protection of the user´s real fake identity is unsafe in previous work. Especially sharing among trusted social relations, location based service provider may unauthorized obtain the user´s complete social relations. In order to solve this problem, we present a security improved mechanism namely B-Mobishare, which uses the Bloom Filter to prevent adversary attack. Finally, the security analysis makes sure that B-Mobishare can effectively protect user´s location privacy and social network privacy.