  This study investigates general model-based incident handler's asymptotic
behaviors in time against cyber attacks to control systems. The attacker's and
the defender's dynamic decision making is modeled as an equilibrium of a
dynamic signaling game. It is shown that the defender's belief on existence of
an attacker converges over time for any attacker's strategy provided that the
stochastic dynamics of the control system is known to the defender. This fact
implies that the rational behavior of the attacker converges to a harmless
action as long as the defender possesses an effective counteraction. The
obtained result supports the powerful protection capability achieved by
model-based defense mechanisms.
