Title: Hypergames and Cyber-Physical Security for Control Systems,
Abstract: The identification of the Stuxnet worm in 2010 provided a highly publicized
example of a cyber attack used to damage an industrial control system
physically. This raised public awareness about the possibility of similar
attacks against other industrial targets -- including critical infrastructure.
In this paper, we use hypergames to analyze how adversarial perturbations can
be used to manipulate a system using optimal control. Hypergames form an
extension of game theory that enables us to model strategic interactions where
the players may have significantly different perceptions of the game(s) they
are playing. Past work with hypergames has been limited to relatively simple
interactions consisting of a small set of discrete choices for each player, but
here, we apply hypergames to larger systems with continuous variables. We find
that manipulating constraints can be a more effective attacker strategy than
directly manipulating objective function parameters. Moreover, the attacker
need not change the underlying system to carry out a successful attack -- it
may be sufficient to deceive the defender controlling the system. It is
possible to scale our approach up to even larger systems, but the ability to do
so will depend on the characteristics of the system in question, and we
identify several characteristics that will make those systems amenable to
hypergame analysis.