Collaborative joint content sharing for online social networks

Online social networks´ (OSNs) epic popularity has accustomed users to the ease of sharing information. At the same time, OSNs have been a focus of privacy concerns with respect to the information shared. Therefore, it is important that users have some assurance when sharing on OSNs: popular OSNs provide users with mechanisms, to protect shared information access rights. However, these mechanisms do not allow collaboration when defining access rights for joint content related to more than one user (e.g, party pictures in which different users are being tagged). In fact, the access rights list for such content is represented by the union of the access list defined by each related user, which could result in unwanted leakage. We propose a collaborative access control scheme, based on secret sharing, in which sharing of content on OSNs is decided collaboratively by a number of related users. We demonstrate that such mechanism is feasible and benefits users´ privacy.