Toward an Adaptive Cyber Resilience Paradigm of Rail Control Systems in the Digital Era

Abstract

Today, the railway industry is experiencing a profound digital transformation driven by advances in ICT technologies such as 5G, cloud computing, and artificial intelligence. In particular, the digitalization of rail control systems has significant potential to reduce system complexity and operating and maintenance costs while improving safety and efficiency. However, in addition to these significant benefits, security has emerged as a critical concern that could no longer be overlooked. Even a minor breach in any digitalized component can propagate through interconnected subsystems and eventually lead to severe safety incidents in the physical world. To holistically address both safety and security in digitalized rail control systems, we propose an adaptive cyber-resilience paradigm by analyzing the characteristics, risks, and requirements of the system. As safety has been extensively studied in the rail domain, this paper focuses primarily on cybersecurity and its interaction and integration with safety. By modeling the railway and its control system as a specialized form of Cyber-Physical System (CPS), we elucidate cybersecurity requirements and introduce a comprehensive risk-analysis methodology to identify the key challenges to achieve cyber resilience. We further define the cyber-resilience paradigm and conduct an in-depth examination of its four essential components: theoretic models, enabling techniques, standards, and practical implementations. Finally, we develop a MAPE-K–based approach and implement this paradigm in the Chinese Train Control System (CTCS), thus demonstrating its feasibility and practical applicability.