Enhanced Virtual Private Social Networks: Implementing user content confidentiality

Virtual Private Social Networks (VPSNs) are a concept that aims at improving the security attributes of untrusted, centralised Online Social Networks (OSNs). Originally conceived with the goal of establishing privacy of user profile data, we propose an extension to the scope of a VPSN to provide confidentiality of shared data in the form of user-generated content. In this paper, we present a novel approach for exchanging confidential content within a VPSN based on symmetric encryption and the use of hash functions. We report on a prototype implementation and show that in practical use our technique introduces a nominal performance overhead. We propose that this could be an important building block for a putative enhanced VPSN application.