Cybersecurity Threat Modelling for Electric Power System SCADA Control Centers and Substation Automation Systems

The increasing automation and reliance on Information and Communication Technologies (ICT) in electric power systems, from generation to utilization, introduce significant cyber threats to critical infrastructure. Malfunctions caused by cyberattacks can lead to cascaded effects across multiple sectors, including defence, aviation, and health, potentially resulting in severe consequences. It is essential to address these cybersecurity threats to ensure grid resilience, and a robust threat model is crucial for designing secure control centers and substation automation system architectures. This paper presents a detailed threat model study for typical Supervisory Control and Data Acquisition (SCADA) control center and substation automation system architectures. Utilizing the STRIDE methodology and the CIA triad principles, the authors identified threats and correlated them with ISO/IEC 27001, ISO/IEC 27002, and IEC 62351 series of standards for mitigation plans. The developed framework was applied to a laboratory SCADA Test bed, and the results are discussed. Several reported cyber incidents were reviewed, applicable ISO/IEC 27002 controls were identified, and it was demonstrated how implementing these controls could have prevented them. The study offers inferences and recommendations for mitigating threats with optimal cost, highlighting the critical role of human factors in minimizing cyber incidents within critical infrastructure.