  Cyber-secure networked control is modeled, analyzed, and experimentally
illustrated in this paper. An attack space defined by the adversary's system
knowledge, disclosure, and disruption resources is introduced. Adversaries
constrained by these resources are modeled for a networked control system
architecture. It is shown that attack scenarios corresponding to
denial-of-service, replay, zero-dynamics, and bias injection attacks can be
analyzed using this framework. Furthermore, the attack policy for each scenario
is described and the attack's impact is characterized using the concept of safe
sets. An experimental setup based on a quadruple-tank process controlled over a
wireless network is used to illustrate the attack scenarios, their
consequences, and potential counter-measures.
