Secure-by-Design Is More Than Just a Cybersecurity Risk Problem

Building trustworthy secure systems has a great deal in common with building a house. It starts with a good architectural plan, input from structural engineers, quality products (e.g., lumber, concrete, plumbing and electrical components, roofing materials, doors and windows), skilled tradespeople to carry out the site grading and construction, building inspections at various stages in the construction process, and a construction supervisor to oversee the work. It’s a well-established construction?process?that is designed to help ensure quality outcomes. The home is, in reality, a “system.” So, after 50 years of trying to develop computing systems that we trust and are resilient in the face of threats from determined adversaries, why is it that we still have significant risk in this area? Why are building codes in home construction and other disciplines far more complete than in cybersecurity?

To be fair, computing systems are highly complex entities composed of trillions of lines of code in software applications and firmware, billions of interconnected devices, and hardware components at the foundation where computer science meets physics. But given those distinct differences, homes and computing systems are both “systems” in their own right. Have we applied the foundational, time-tested?design principles in a life cycle-based systems engineering process to produce?outcomes?that we need to ensure our critical systems (integral to everything we care about including our privacy) are well protected? Do we have sufficient information to understand how system components are designed and built and how those products come together in a system to provide critical capabilities that keep the lights on, purify water systems, keep the planes, trains and automobiles running, ensure ubiquitous communications essential for commerce, and protect the country with reliable, state-of-the-practice weapons systems?

There are many ongoing initiatives to improve the security and transparency of component products developed by industry and to promote a secure-by-design approach to cybersecurity. The fundamental problem, however, cannot be constrained to cybersecurity risk—rather, it is a much broader problem that extends into the world of systems and system complexity. Building trustworthy secure systems and systems that have sufficient?resilience to operate in stressful environments with a myriad of threats requires “systems thinking” and the discipline of a well-defined?systems engineering process?that can reduce and manage complexity.

Having quality component products with security features is a necessary condition for achieving trustworthy secure systems, but it is certainly not sufficient. Why? Because “the adversaries live in the cracks.” Just like you can build a structurally-unsound home with quality products, you can also build an untrustworthy system with individual component products loaded with security features. A lack of?intentional?systems thinking and systems engineering results in systems that are more susceptible to successful cyber-attacks and subject to ongoing, expensive maintenance activities (e.g., remediating a growing list of system vulnerabilities, including zero-days after-the-fact, that require patching). Recognizing the holistic nature of “computing systems” is important for building the types of systems (including cyber-physical systems) we depend on to keep the country safe, secure, and productive.

A special note of thanks to?Victoria PIllitteri and?Brian Barnier, long-time cybersecurity and SSE colleagues, who graciously reviewed and provided sage advice for this article.