Abstract
Modern infrastructure systems are complex, interconnected cyber physical system (CPS) that form the lifeline of our society. Recent trends in security indicate the increasing threat of cyber-based attacks, both in numbers and sophistication, on critical infrastructure systems of the world in general. In this talk, I will address resource-constrained attack-defense scenarios on systems modelled as graphs. Specifically, I will consider utility functions that are additive. By leveraging necessary structural properties of Nash equilibria, I will present a characterization of the possible Nash equilibria and demonstrate the existence of a game exhibiting each type. Further, I will present a novel O(m^3) algorithm to compute equilibria based upon our structural analysis where m is the number of assets to be protected. Under the assumption that the defender can perturb the payoffs to the attacker, I will show that the problem of maximizing the expected outcome to the defender is weakly NP-hard in the case of Stackelberg equilibria and multiple attacker resources, and propose a pseudopolynomial time procedure based upon our theory of types to find a globally optimal solution to the problem of maximizing defender expected utility in the case of Nash equilibria under a disjointness assumption. I will conclude my talk with implications of these results for a zero-sum game on a restricted model of the utility function.
Biography
Sourabh Bhattacharya is a faculty at Iowa State University. He obtained his PhD from University of Illinois at Urbana-Champaign in 2010, and an undergraduate degree from IIT, Bombay in 2002. His research interests are in game theory and control with applications in cyber-physical systems.
