Cybersecurity Risk Assessment of Wheel Slide Protection System in Railways

The Wheel Slide Protection (WSP) system plays a critical safety role in railway braking by preventing wheel lock and maintaining adhesion control under low-friction conditions. While traditionally seen as isolated and secure, the growing sophistication of cyber threats and the rail sector's rising profile as a target reveal the need to reassess its cybersecurity posture. Even non-networked, safety-critical subsystems like WSP can be exposed to cyber-physical risks. This paper presents a structured methodology for conducting a cybersecurity risk assessment of the Wheel Slide Protection (WSP) system, in alignment with the TS 50701:2023 cybersecurity standard for the railway sector. To the best of our knowledge, this is the first study to assess the WSP subsystem from a cybersecurity standpoint using a formal, standards-based approach. Our contributions are threefold: (1) we perform a functional and architectural decomposition of the WSP system to identify its key functions and critical interfaces; (2) we apply a lifecycle-based methodology to generate traceable cybersecurity artefacts; and (3) we evaluate the effectiveness of structured security activities in supporting the risk assessment and protection of such safety-critical railway subsystems.