Structural Resilience of Cyberphysical Systems

The resilience of cyberphysical systems (CPS) to denial of service (DoS) and integrity attacks is studied. The CPS is modeled as a linear structured system, and its resilience to various attack scenarios is interpreted in a graph theoretical framework. The structural resilience of the CPS to DoS and integrity attacks is characterized in terms of unmatched vertices in maximum matchings of the bipartite graph and connected components of directed graph representations of the CPS under attack. Further, we prove that if a system is structurally resilient to a DoS attack for some defender input matrix [Bdef ], with zero structure Z (Bdef ), then there exists a [Bde f ] with Z (B ′ de f )⊆Z (Bdef ) for which it will also be structurally resilient to a state feedback integrity attack. If an additional condition holds, we show that the same [Bdef ] will ensure structural resilience to a state feedback integrity attack.