User Search with Knowledge Thresholds in Decentralized Online Social Networks

User search is one fundamental functionality of an OSN. When building privacy-preserving DOSNs, the challenge of protecting user data and making users findable at the same time has to be met. We propose a user-defined knowledge threshold (”find me if you know enough about me”) to balance the two requirements. We present and discuss protocols for this purpose that do not make use of any centralized component. An evaluation using real world data suggests that there is a promising compromise with good user performance and high adversary costs.