Resource Efficient Privacy Preservation of Online Social Media Conversations

On today’s online social networks (OSNs), users need to reveal their content and their sharing patterns to a central provider. Though there are proposals for decentralized OSNs to protect user privacy, they have paid scant attention to optimizing the cost borne by users or hiding their sharing patterns. In this paper, we present Hermes, a decentralized OSN architecture, designed explicitly with the goal of hiding sharing patterns while minimizing users’ costs. In doing so, Hermes tackles three key challenges: 1) it enables timely and consistent sharing of content, 2) it guarantees the confidentiality of posted private content, and 3) it hides sharing patterns from untrusted cloud service providers and users outside a private group. With extensive analyses of Hermes using traces of shared content on Facebook, we estimate that the cost borne per user will be less than $5 per month for over 90% of users. Our prototype implementation of Hermes demonstrates that it only adds minimal overhead to content sharing.