Saving Privacy in Trust-Based User-Centric Distributed Systems

User-centricity is a design philosophy subsuming new models of Internet connectivity and resource sharing, whose development is mainly driven by what users offer and require. To promote user-centric services and collaborative behaviors, incentives are needed that are typically based on trust relations and remuneration. In this paper, we show that privacy-preserving mechanisms can favor user's involvement if privacy can be traded with trust and cost. In particular, we present and evaluate formally a model ensuring an adequate level of flexibility among privacy, trust, and cost in the setting of distributed systems