Moving Target Defense for Detecting Coordinated Cyber-Physical Attacks on Power Grids via a Modified Sensor Measurement Expression

Abstract

This paper proposes a modified sensor measurement expression for a moving target defense (MTD) strategy to detect coordinated cyber-physical attacks (CCPAs). Essentially, the MTD defense characteristics for detecting false data injection attacks (FDIAs) differ from those used to detect CCPAs. In the first case, the MTD performance in detecting FDIAs at the attack-execution stage is mainly considered, which is generally denoted by the detection probability; however, whether the construction of undetectable CCPAs is disrupted via the MTD strategy used during the attack-preparation stage is the focus of the latter case. There has been little work on the detection of undetectable CCPAs in the context of MTD post-activation. In our work, a novel approach to detecting undetectable CCPAs via a modified sensor measurement expression is proposed. First, the production mechanism for undetectable CCPAs without the application of an MTD strategy is transferred to that which occurs after MTD activation; then, based on an in-depth analysis of the CCPAs’ production mechanism after MTD activation, a novel modified sensor measurement expression is presented to detect undetectable CCPAs. Extensive simulations were conducted on three standard power systems to verify the effectiveness and simplicity of our approach to detecting CCPAs.