SoNet -- Privacy and Replication in Federated Online Social Networks

In this paper we propose a federated online social network (OSN) which focuses on user privacy and data availability. All user content is encrypted and decrypted on end-user devices, hiding the content from the OSN providers. The social graph is hidden from the OSN provider by employing a novel aliasing approach and using secure algorithms for mutual friendship establishment. Usernames are mapped to friend-specific aliases, which reduces the amount of information a provider can gather from analyzing these identifiers. Users authenticate to each other without revealing their identities to a potential attacker. The proposed system allows for user interactions between independent OSN providers. To improve data availability we use a replication scheme which does not jeopardize the obfuscation of the social graph. Our approach differs from existing works mainly by the social graph obfuscation in combination with replication.