Merging safety and cybersecurity analysis in product design
Dajiang Suo, Joshua Eric Siegel, Sanjay Emani Sarma · IET Intelligent Transport Systems · 2018
When developing cyber‐physical systems such as automated vehicles, safety and cybersecurity analyses are often conducted separately. However, unlike in the IT world, safety hazards and cybersecurity threats converge in cyber‐physical systems; a malicious party can exploit cyber‐threats to create extremely hazardous situations, whether in autonomous vehicles or nuclear plants. The authors propose a framework for integrated system‐level analyses for functional safety and cyber security. They present a generic model named Threat Identification and Refinement for Cyber‐Physical Systems (TIRCPS) extending Microsoft's six classes of threat modelling including Spoofing, Tampering, Repudiation, Information Disclosure, Denial‐of‐Service and Elevation Privilege. TIRCPS introduces three benefits of developing complex systems: first, it allows the refinement of abstract threats into specific ones as physical design information becomes available. Second, the approach provides support for constructing attack trees with traceability from high‐level goals and hazardous events (HEs) to threats. Third, TIRCPS formalises the definition of threats such that intelligent tools can be built to automatically detect most of a system's vulnerable components requiring protection. They present a case study on an automated‐driving system to illustrate the proposed approach. The analysis results of a hierarchical attack tree with cyber‐threats traceable to high‐level HEs are used to design mitigation solutions.