operties of compositionality and referential transparency. As depicted in the figure below, two interdependent research threads are required, one for systems subject to intrusions and one for system environments from which intrusions arise. Each thread can progress through three stages. The first, IA Theory, defines scientific principles for information assurance. The second, IA Representation,
... [Show full abstract] defines specification languages and reasoning methods and tools based on the theoretical findings. The third, IA Engineering, defines engineering practices for analysis and design, based on the theoretical foundations, specification languages, and reasoning methods. At present, no comprehensive theory of information systems exists that can guide construction and evaluation of IA in large-scale systems. As a result, creating an acceptable level of information assurance in these systems exceeds current capabilities. Scalable theoretical foundations for specifying, analyzing, and designing these