A Formal Privacy Policy Framework for Social Networks

Paper in proceeding, 2014

Social networks (SN) provide a great opportunity to help people interact with each other in different ways depending on the kind of relationship that links them. One of the aims of SN is to be flexible in the way one shares information, being as permissive as possible in how people communicate and disseminate information. While preserving the spirit of SN, users would like to be sure that their privacy is not compromised. One way to do so is by providing users with means to define their own privacy policies and give guarantees that they will be respected. In this paper we present a privacy policy framework for SN, consisting of a formal model of SN, a knowledge-based logic, and a formal privacy policy language. The framework may be tailored by providing suitable instantiations of the different relationships, the events, the propositions representing what is to be known, and the additional facts or rules a particular social network should satisfy. Besides, models of Facebook and Twitter are instantiated in our formalism, and we provide instantiations of a number of richer privacy policies.