Gay, RichardRichardGayHu, JinweiJinweiHuMantel, HeikoHeikoMantelMazaheri, SogolSogolMazaheri2022-10-272022-10-272017-10Lecture Notes in Computer Science 10723 LNCS: 18-34 (2018)http://hdl.handle.net/11420/13845Decentralized online social networks (DOSNs) have adopted quite coarse-grained policies for sharing messages with friends of friends (i.e., resharing). They either forbid it completely or allow resharing of messages only without any possibility to constrain their subsequent distribution. In this article, we present a novel enforcement mechanism for securing resharing in DOSNs by relationship-based access control and user-determined privacy policies. Our mechanism supports resharing and offers users control over their messages after resharing. Moreover, it addresses the fact that DOSNs are run by multiple providers and honors users’ choices of which providers they trust. We clarify how our mechanism can be effectively implemented by a prototype for the DOSN Diaspora*. Our experimental evaluation shows that controlling privacy with our prototype causes only a rather small performance overhead.enAccess controlDecentralized online social networksPrivacyInformatikConference Paper10.1007/978-3-319-75650-9_2Other