Cybersecurity in Intelligent Railway Systems:Taxonomy, Research Trends, Challenges, and Future Directions

The rapid digitalisation unfolding in railway systems poses new cybersecurity concerns, thereby requiring solutions that will take the necessary steps to defend against tangible emerging threats. This study aims to systematically review the current cybersecurity research landscape within railway systems. Using a systematic protocol, we comprehensively searched five key online databases: IEEE Xplore, Web of Science, Scopus, ACM, and ScienceDirect. These online databases are recognised for their overall broad coverage and the exhibition of relevance to this study's purpose. Our systematic selection process, facilitated through a predetermined set of inclusion and exclusion criteria, resulted in 114 relevant articles. Among them, 51.8% of the articles reviewed also addressed Control System Security Solutions, while 14% of the articles examined Network Security Solutions, and 12.3% addressed Data Protection and Privacy Solutions. 7% of the articles studied Awareness and Training Solutions, while the remaining 14.9% adopted other approaches. Results identified several significant gaps and challenges relating to railway cybersecurity research, which includes issues relating to embracing critical technologies, confirming data privacy, and the need for ongoing education and training of railway workers. Additionally, the study indicated a lack of standardised performance measures and use of testing datasets, which will impact confidence in measuring the effectiveness of cybersecurity solutions. Ultimately, this research paper advances understanding and contributions to the current railway cybersecurity research landscape, while providing critical recommendations for future research. Efforts towards enhancing international collaboration, adopting emergent technologies such as AI and Blockchain and prioritising education and awareness initiatives are some of the most critical emerging next steps related to cybersecurity and resilience of railway systems.