SOUP

Abstract

Concomitant with the tremendous growth of online social networking (OSN) platforms are increasing concerns from users about their privacy and the protection of their data. As user data management is usually centralized, OSN providers nowadays have the unprecedented privilege to access every user's private data, which makes large-scale privacy leakage at a single site possible. One way to address this issue is to decentralize user data management and replicate user data at individual end-user machines across the OSN.However, such an approach must address new challenges. In particular, it must achieve high availability of the data of every user with minimal replication overhead and without assuming any permanent online storage. At the same time, it needs to provide mechanisms for encrypting user data, controlling access to the data, and synchronizing the replicas. Moreover, it has to scale with large social networks and be resilient and adaptive in handling both high churn of regular participants and attacks from malicious users.While recent works in this direction only show limited success, we introduce a new, decentralized OSN called the Self-Organized Universe of People (SOUP). SOUP employs a scalable, robust and secure mirror selection design and can effectively distribute and manage encrypted user data replicas throughout the OSN. An extensive evaluation by simulation and a real-world deployment show that SOUP addresses all aforementioned challenges.