PLocShare: A privacy-preserving location sharing scheme in mobile social network

Location sharing is an increasingly popular function of mobile social networks. Users´ locations may reveal sensitive private information, such as habits, interests, activities and health conditions. The biggest users´ concern about location sharing services is privacy. There are some encounter-based social scenarios where a user´s location may be shared with strangers in proximity. In these scenarios, the user and near people who want to get the shared location has not shared keys in advance to ensure the privacy of the location. In addition, the user does not want to be always online to involve in every access of the shared location. The existed location sharing solutions are not appropriate to be used in these scenarios. In this paper, a privacy-preserving location sharing scheme PLocShare is proposed. The scheme is based on ciphertext-policy attribute based encryption (CP-ABE), and the security analysis shows that it ensures secure location sharing in encounter-based social scenarios.