We 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 her privacy is to help
another player in preserving his 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. We formally define coprivacy in terms of Nash equilibria. We then extend the concept to:
i) general coprivacy, where a helping player’s utility (i.e. interest) may include earning functionality
and security in addition to privacy; ii) mixed coprivacy, where mixed strategies and mixed Nash
equilibria are allowed with some restrictions; iii) correlated coprivacy, in which Nash equilibria are
replaced by correlated equilibria. Coprivacy can be applied to any peer-to-peer (P2P) protocol.
We illustrate coprivacy in P2P anonymous keyword search, in content privacy in social networks,
in vehicular network communications and in controlled content distribution and digital oblivion
enforcement