Enhancing Cyber-Physical Resiliency of Power Grids under IoT-Enabled Dynamic Botnet Attacks

The wide adoption of Internet of Things (loT)-enabled energy devices improves the quality of life, but simultaneously, it enlarges the attack surface of the power grid system. The adversary can gain illegitimate control of a large number of these devices and use them as a mean to compromise the physical grid operation, a mechanism known as the loT botnet attack. This paper aims to improve the resiliency of cyber-physical power grids to such attacks. Specifically, we use an epidemic model to understand the dynamic botnet formation which facilitates the assessment of cyber layer vulnerability of the grid. The attacker aims to exploit this vulnerability to enable a successful physical compromise, while the system operator's goal is to ensure a normal operation of the grid by mitigating cyber risks. We develop an optimization framework for effective defense design that enhances cyber-physical grid resiliency by considering strategic attack behaviors. Case studies are used to corroborate the devised approach.