Cybersecurity – the discipline associated with protecting systems, networks, and products from cyber attack – has been on the forefront of concerns in the Department of Defense for decades. While this will continue to be a critical aspect for defense systems, cyber-resilience is becoming increasingly important. SERC Researcher, Dr. Peter Beling, Virginia Tech, has led research tasks on operational resilience – the ability of systems to resist, absorb, and recover from or adapt to an adverse occurrence. The tasks explore not only principles for and definition characteristics of operational resilience, but also the special development, testing, and evaluation considerations needed for operational resilience. A principal outcome of these projects is a framework for determining requirements for resilience and associated test metrics.
In prior SERC research projects, the research team developed mission aware (MA) architecture, a reference architecture for operational resilience of cyber-physical systems. The primary feature of the MA architecture is a sentinel that monitors the system or mission being protected, detects abnormal behavior or other signs of loss of function, alerts system users or mission owners to detected loss of function, and has the capability to switch the system or mission to a resilient mode of operation, which is a distinct and separate method of operation. Resilient modes of operation are designed so that the system can still meet the primary objectives of the mission, though with possible loss of operational performance. In addition, resilience includes containing the immediate consequences of the detected attack and post-attack forensic support based upon the data collected for addressing anomalies.
Dr. Beling explained, “It is generally recognized that we cannot prevent all cyber threats from impacting our systems, so there are a lot of ways when looking at something like a weapons system or vehicle or any military system where there is a lot of opportunity for advanced persistent threats to have an impact. Adversaries can find a way into systems. This work focuses on the idea of resilience to cyber attacks and potentially other disruptions. Resilience is the capacity of a system to fight through and recover from a successful attack. This is important for trying to react to persistent threats.”
The role of systems engineers in resilience is to help people understand how to design cyber-resilient systems, test for them, and take them through the systems engineering process. The SERC research is attempting to deal with that question of considering resilience and doing it early in the systems lifecycle before requirements and design have advanced. The goal is to reason about cyber-resilience before the system exists. The key to the notion is looking at the functions of the system and how those potentially play a role in providing resilience. Dr. Beling continued, “Thinking at a functional level instead of about hardware and software is something we can do before we make those choices on system elements. Model-based systems engineering and digital engineering techniques help us reason about how a system might respond to an attack or other adverse condition. That capability, in turn, gives us a basis for exploring trades and design and architecting ultimately for setting requirements and thinking through issues like testing the system for resilience.”
Many MBSE efforts and perspectives focus on the infrastructure of a system, its interfaces, or parametrics. This is a shift to focus on notions of system function – how the elements end up working together. That is the key to understanding what must be preserved about a system under attack and a key to understanding how to go about preserving those functions.
These tasks may ultimately impact how programs manage things but also how community understands how functional modeling is central to the development of secure and cyber-resilient engineered systems for the DoD. The team is currently engaged with the Defense Acquisition University (DAU) and developing courseware around cyber-resilience as a follow-on activity. An essential step is to help DAU, and by extension the workforce, understand how to support cyber-resilience in acquisition through the use of systems modeling and digital engineering.
The team is also actively identifying programs to pilot these methods and tools and to help people in the programs apply them. For additional information or for interest in the pilot process, contact Dr. Peter Beling.
The “WRT-1022: Developmental Test and Evaluation (DTE&A) and Cyberattack Resilient Systems” Final Technical Report was re-released on October 7, 2021.