This paper proposes a stealthy integrity attack
generation methodology for a class of nonlinear cyber-physical
systems. Geometric control theory and stability theory of incremental
systems are used to design an attack generation scheme
with stealthiness properties. An attack model is proposed as a
closed-loop dynamical system with an arbitrary input signal. This
model is developed based on a controlled invariant subspace that
results from geometric control theory and is decoupled with the
system outputs and the nonlinear function. The presence of the
arbitrary signal in the attack model provides an additional degree
of freedom and constitutes a novel component compared with
existing results. The stealthiness of the attack model is rigorously
investigated based on the incremental stability of the closed-loop
control system, and the incremental input-to-state stability of the
anomaly detector. As a result, a sufficient condition in terms of
the initial condition of the attack model is derived to guarantee
stealthiness. Finally, a case study is presented to illustrate the
effectiveness of the developed attack generation scheme.
