Game theory applications in security?

Countering terrorism is currently at the top of the national security agenda in the United States and many other countries around the world. Within this effort, protecting critical infrastructures against terrorism is one of the top priorities in homeland security. Public transit systems, places of mass gathering and water/energy supply networks are considered as part of the infrastructure. Such systems are, by design, open structural environments equipped to house/move large numbers of people or supplies in an effective and efficient manner. These places are considered soft targets that are inherently vulnerable to terrorist attacks. Developing optimal strategies to protect such infrastructure systems poses many challenges that have not been comprehensively addressed in the previous research efforts. One of these challenges is the dynamic nature of crowd sizes inside these systems. Because the attacker's primary objective is to inflict human casualties, his/her payoff value for each site depends on the number of people residing in the site. These numbers may be different for different sites and they may change over time. Another challenge is to develop schedules that observe the constraints regarding human resources. For example, the generated schedules may be required to include breaks for the security teams and these breaks should not be consecutive. Another challenge is decision making in different levels in an organization's hierarchy. Even though most researchers study these decisions separately, they influence each other and should be studied simultaneously in a comprehensive model. Finally, protecting the infrastructure and its users against possible attacks involves decision making under uncertainty. For example, the location, the power/time of potential attacks or even the attacker's purpose may be unknown to the defender. To develop efficient protection strategies for the infrastructures against terrorism, there are two specific goals in this research: (1) to develop game-theoretic models to capture the strategic interaction among different players in the critical infrastructures; (2) to develop efficient protection strategies and enhance the security of such infrastructures against intentional attacks. In order to achieve these goals, static and dynamic game models will be developed to capture the multi-level and dynamic nature of such decision making. Robust and Bayesian game-theoretic modelling approaches will be used to address the inherent uncertainties. Furthermore, to obtain the optimum protection strategies, as prescribed by the Nash equilibrium in the developed models, efficient solution methods based on column generation and decomposition approaches will be used. "Note: This project contains a research and/or development component, as defined in applicable law," and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14). ca/ncf