Strategic Information Revelation and Commitment in Security Games

The Strong Stackelberg Equilibrium (SSE) has drawn extensive attention recently in several security domains, which optimizes the defender's random allocation of limited security resources. However, the SSE concept neglects the advantage of defender's strategic revelation of her private information, and overestimates the observation ability of the adversaries. In this paper, we overcome these restrictions and analyze the tradeoff between strategic secrecy and commitment in security games. We propose a Disguised-resource Security Game (DSG) where the defender strategically disguises some of her resources. We compare strategic information revelation with public commitment and formally show that they have different advantages depending the payoff structure. To compute the Perfect Bayesian Equilibrium (PBE), several novel approaches are provided, including basic MILP formulations with mixed defender strategy and compact representation, a novel algorithm based on support set enumeration, and an approximation algorithm for epsilon-PBE. Extensive experimental evaluation shows that both strategic secrecy and Stackelberg commitment are critical measures in security domain, and our approaches can solve PBE for realistic-sized problems with good enough and robust solution quality.