On the Tradeoff between Privacy and Utility in Collaborative Security-A Game Theoretical Approach

With the rapid development of sophisticated attack techniques, individual security systems which base all of their decisions and actions of attack prevention and response on their own observations and knowledge become incompetent. To cope with this problem, collaborative security that coordinates security entities to perform specific security actions is proposed and developed in literature. In collaborative security schemes, multiple entities collaborate with each other by sharing some security evidence or analysis results so as to make more effective and reasonable decisions. Nevertheless, the information exchange raises privacy concerns, especially for those privacy-sensitive entities. In order to obtain a quantitative understanding of the fundamental tradeoff between the effectiveness of collaboration and the entities’ privacy, a repeated two-layer single-leader multifollower game is proposed in this work. Based on our gametheoretic analysis, the expected behaviors of both the attacker and the security entities are derived and the utility-privacy tradeoff curve is obtained. In addition, the existence of Nash equilibrium (NE) is proved and an asynchronous dynamic update algorithm is proposed to compute the optimal collaboration strategies of the entities. Furthermore, the existence of Byzantine entities is considered and its influence is investigated. Finally, simulation results are shown to validate the analysis.