A Systems Security Approach for Requirements Analysis of Complex Cyber-Physical Systems

Abstract

Today's highly interconnected and technology reliant environment places greater emphasis on the need for dependably secure systems. This work addresses this problem by detailing a systems security analysis approach for understanding and eliciting security requirements for complex cyber-physical systems. First, a readily understandable description of key architectural analysis definitions and desirable characteristics is provided along with a survey of commonly used security architecture analysis approaches. Next, a tailored version of the System-Theoretic Process Analysis approach for Security (STPA-Sec) is detailed in three phases which supports the development of functional-level security requirements, architectural-level engineering considerations, and design-level security criteria. In particular, these three phases are aligned with the systems and software engineering processes defined in the security processes of NIST SP 800–160. Lastly, this work is important for advancing the science of systems security by providing a viable systems security analysis approach for eliciting, defining, and analyzing traceable security, safety, and resiliency requirements which support evaluation criteria that can be designed-for, built-to, and verified with confidence.