Abstract
Contextual Integrity has been proposed to define privacy in an unusual way. Most approaches take into account a sensitivity level or a “privacy circle”: the information is said to be either private or public and to be constrained to a given group of agents, e.g. “my friends”, when private. In the opposite, Contextual Integrity states that any information transmitted can make this transmission a privacy violation depending on its context. We use this theory to develop a novel framework that one can use in an open and decentralized virtual community to socially enforce privacy. This paper proposes the PrivaCIAS framework, in which privacy constraints are formally described to be used to detect privacy violations according to the Contextual Integrity theory. This PrivaCIAS framework provides social control to agents that handle the information, so that deceiving agents are excluded from the system.