The SSP is a high assurance systems engineering effort spanning both hardware and software. Extensive design review, first principle design, n-version programming, program transformation, verification, and consistency checking are the techniques used to provide assurance in the correctness of the resulting system.
Citation:
Gregory L. Wickstrom, Jared Davis, Steven E. Morrison, Steve Roach, Victor L. Winter, "The SSP: An Example of High-Assurance Systems Engineering," hase, pp.167-177, Eighth IEEE International Symposium on High Assurance Systems Engineering (HASE'04), 2004