Comparative Studies of Security Assessment Methods for Railway Control Systems

As one of the typical Industrial Control System (ICS), railway control systems nowadays are faced with many security risks during its digital transformation empowered by various Information and Communications Technology (ICT), e.g., AI, 5G/6G. In addition to ensuring safety, the fundamental property of railway control system, it is important to conduct comprehensive security assessment during their design, development, deployment, and maintenance. But how to select and apply the most appropriate and efficient assessment methods is not straightforward and deserves careful studies. This paper firstly provides an in-depth analysis of the existing standards•1 for secure design and security assessment of railway control systems, in order to clarify the relationship between safety and security. It then comparatively studies the qualitative, quantitative, and simulation-based security assessment methods, along with their application scenarios, with an objective to obtaining an effective combination of these methods for railway control systems. By taking into account the specific security requirements and system characteristics of rail control systems, we finally propose a comprehensive security assessment framework for rail control systems.