Perennial security problems seem to become ever more daunting as embedded computing becomes ubiquitous and the stakes rise for the defense of such systems. The LynxSecure Separation Kernel is a foundational component for the construction of high-assurance secure systems. Developers of such systems must provide convincing assurance cases for the trustworthiness of such systems. This class describes how LynxSecure supports the development of high-assurance secure systems and how developers can approach the system design and assurance activity. This class is based on the LynxSecure Separation Kernel and upon research being performed at SRI international under the auspices of AFRL and Raytheon.