The following is a (very) brief review of linear system theory and Fourier analysis. I work primarily with discrete signals, but each result developed in this review has a parallel in terms of continuous signals and systems. I assume the reader is familiar with linear algebra (as reviewed in my handout Geometric Review of Linear Algebra), and least squares estimation (as reviewed in my handout ...

In this paper, two independent definitions of system security are given through two distinct aspects of a system execution, i.e. state and transform. These two definitions are proven to be equivalent, which gives both confidence to the soundness of our explication and insight into the internal causality of information flow. Using this definition of information flow security, a general security ...