Signalling and Cyber Security: Closing the gaps that prevent comprehensive security solutions

Author: John Boss
Day: Aspect Day One
Session: Cyber Resilience, reserve paper

Cyber security is an issue that needs to be addressed in signalling systems. There are however, no cyber security standards for signalling. Cyber security is a multi system problem, and further complicated by the fact that signalling and security disciplines are different in nature. The critical issue is the potential for misalignment of context. – in particular, how the signalling engineer views 'the problem' may not align with the actual cyber security challenge that needs to be addressed. Simply encrypting some data channels is not in itself a comprehensive solution. This paper examines that potential misalignment of context, by reflecting on three paradigms of signalling, viewed through a cyber security prism. Firstly, the definition of a system that is used by signalling engineers is compared with security architectures currently defined in cyber security standards for industrial applications to highlight gaps. Secondly, the definition, and process of risk analysis is compared to reveal underlying differences between signalling and security concepts - but also highlight areas of commonality. Finally, the signalling approach to updating safety code is compared is with the IT practice of updating (patching), and examples are discussed that are attempting to address the issues that result. The conclusion is that close collaboration is necessary between the safety engineers and the security engineers to ensure comprehensive cyber security solutions for railways are developed. Interactions are mapped against phases of EN50126.