Coprivacy: Towards a Theory of Sustainable Privacy
The authors introduce the novel concept of coprivacy or co-operative privacy to make privacy preservation attractive. A protocol is coprivate if the best option for a player to preserve the user privacy is to help another player in preserving their privacy. Coprivacy makes an individual's privacy preservation a goal that rationally interests other individuals: it is a matter of helping oneself by helping someone else. They formally define coprivacy in terms of nash equilibria. They then extend the concept to: general coprivacy, where a helping player's utility (i.e. interest) may include earning functionality and security in addition to privacy; mixed coprivacy, where mixed strategies and mixed Nash equilibria are allowed with some restrictions; correlated coprivacy, in which Nash equilibria are replaced by correlated equilibria.