Design of a coordinated cyber-physical attack in IoT based smart grid under limited intruder accessibility

The wider geographical span and deep penetration of information and communication (ICT) tools have increased the vulnerability of power networks to physical and cyberattacks. A coordinated cyber-physical (CP) attack is known to cause increased disruption in the internet of things (IoT) based smart grid (SG) operation as compared to a physical or cyberattack carried out in isolation. In this work, the design of a coordinated CP attack has been framed as a constrained optimization problem and solved using binary grey-wolf optimization (GWO) technique. Considering the increased dependence of network operations on state variables, the attack aims at hiding the impact of maximizing the deviation in the estimated state variables from the pre-attack scenario. The physical attack design considers the practical constraint of critical line inaccessibility to launch an attack. The two-stage attack formulation involves identification of an optimal network topology for maximizing the impact of physical attack, followed by launching an attack in the communication layer to hide the implication of physical attack at the control center. With the physical attack being masked, the control measures to minimize its impact are not executed, thereby leading to possible system shutdown. The validation of the scheme on IEEE 14, 30, and 57 bus benchmark power systems reflects its effectiveness in causing disruption in state estimation (SE) process with reduced attack cost.