Constrained Social-Energy Minimization for Multi-Party Sharing in Online Social Networks.

The development of fair and practical policies for shared content online is a primary goal of the access control community. Multi-party access control, in which access control policies are determined by multiple users each with vested interest in a piece of shared content, remains an outstanding challenge. Purposeful or accidental disclosures by one user in an online social network (OSN) may have negative consequences for others, highlighting the importance of appropriate sharing mechanisms. In this work, we develop a game-theoretic framework for modeling multi-party privacy decisions for shared content. We assume that the content owner (uploader) selects an initial privacy policy that constrains the privacy settings of other users. We prove the convergence of users' access control policies assuming a multi-round consensus-building game in which all players are fully rational and investigate a variation of rational play that better describes user behavior and also leads to the rational equilibrium. Additionally, in an effort to better approximate human behavior, we study a bounded rationality model and simulate real user choices in this context. Finally, we validate model assumptions and conclusions using experimental data obtained through a study of 95 individuals in a mock-social network.