Biblio

This work describes a top down systems security requirements analysis approach for understanding and eliciting security requirements for a notional small unmanned aerial system (SUAS). More specifically, the System-Theoretic Process Analysis approach for Security (STPA-Sec) is used to understand and elicit systems security requirements. The effort employs STPA-Sec on a notional SUAS system case study to detail the development of functional-level security requirements, design-level engineering considerations, and architectural-level security specification criteria early in the system life cycle when the solution trade-space is largest rather than merely examining components and adding protections during system operation or sustainment. These details were elaborated during a semester independent study research effort by two United States Air Force Academy Systems Engineering cadets, guided by their instructor and a series of working group sessions with UAS operators and subject matter experts. This work provides insight into a viable systems security requirements analysis approach which results in traceable security, safety, and resiliency requirements that can be designed-for, built-to, and verified with confidence.

Today's highly interconnected and technology reliant environment places great emphasis on the need for secure cyber-physical systems. This work addresses this need by detailing a top down systems security requirements analysis approach for understanding and eliciting security requirements for a notional space system. More specifically, the System-Theoretic Process Analysis approach for Security (STPA-Sec) is used to understand and elicit systems security requirements during the conceptual stage of development. This work employs STPA-Sec in a notional space system to detail the development of functional-level security requirements, design-level engineering considerations, and architectural-level security specifications early in the system life cycle when the solution trade-space is largest rather than merely examining components and adding protections during system operation, maintenance, or sustainment. Lastly, this approach employs a holistic viewpoint which aligns with the systems and software engineering processes as detailed in ISO/IEC/IEEE 152SS and NIST SP SOO-160 Volume 1. This work seeks to advance the science of systems security by providing insight into a viable systems security requirements analysis approach which results in traceable security, safety, and resiliency requirements that can be designed-for, built-to, and verified with confidence.

The supervisory control and data acquisition (SCADA) network in a smart grid requires to be reliable and efficient to transmit real-time data to the controller. Introducing SDN into a SCADA network helps in deploying novel grid control operations, as well as, their management. As the overall network cannot be transformed to have only SDN-enabled devices overnight because of budget constraints, a systematic deployment methodology is needed. In this work, we present a framework, named SDNSynth, that can design a hybrid network consisting of both legacy forwarding devices and programmable SDN-enabled switches. The design satisfies the resiliency requirements of the SCADA network, which are specified with respect to a set of identified threat vectors. The deployment plan primarily includes the best placements of the SDN-enabled switches. The plan may include one or more links to be installed newly. We model and implement the SDNSynth framework that includes the satisfaction of several requirements and constraints involved in resilient operation of the SCADA. It uses satisfiability modulo theories (SMT) for encoding the synthesis model and solving it. We demonstrate SDNSynth on a case study and evaluate its performance on different synthetic SCADA systems.

A significant number of the generation, transmission and distribution facilities in the North America were designed and configured for serving electric loads and economic activities under certain reliability and resiliency requirements over 30 years ago. With the changing generation mix, the electric grid is tasked to deliver electricity made by fuel uncertain and energy limited resources. How adequate are the existing facilities to meet the industry expectations on reliability? What level of grid resiliency should be designed and built to sustain reliable electric services given the increasing exposure to frequent and lasting severe weather conditions? There is a need to review the modeling assumptions, operating and maintenance records before we can answer these questions.

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.