There is a growing threat to the cyber-security of safety-critical systems.
The introduction of Commercial Off The Shelf (COTS) software, including
Linux, specialist VOIP applications and Satellite Based Augmentation Systems
across the aviation, maritime, rail and power-generation infrastructures has created
common, vulnerabilities. In consequence, more people now possess the technical
skills required to identify and exploit vulnerabilities in safety-critical systems.
Arguably for the first time there is the potential for cross-modal attacks
leading to future ‘cyber storms’. This situation is compounded by the failure of
public-private partnerships to establish the cyber-security of safety critical applications.
The fiscal crisis has prevented governments from attracting and retaining
competent regulators at the intersection of safety and cyber-security. In particular,
we argue that superficial similarities between safety and security have led
to security policies that cannot be implemented in safety-critical systems. Existing
office-based security standards, such as the ISO27k series, cannot easily be integrated
with standards such as IEC61508 or ISO26262. Hybrid standards such as
IEC 62443 lack credible validation. There is an urgent need to move beyond
high-level policies and address the more detailed engineering challenges that
threaten the cyber-security of safety-critical systems. In particular, we consider
the ways in which cyber-security concerns undermine traditional forms of safety
engineering, for example by invalidating conventional forms of risk assessment.
We also summarise the ways in which safety concerns frustrate the deployment of
conventional mechanisms for cyber-security, including intrusion detection systems