I am taking a course in linear algebra which was to be credited towards a program in applied math. My interests have moved towards matters of "security" (information, network, cryptographic, etc.). It seems that the math required for security is more towards discrete math and finite automata, probability theory, and number theory. Is there any motivation to study linear algebra? What are its applications to "security"?
For example, there's the concept of a "protection matrix", but I'm not sure if this can be related to the "matrix" in the linear algebra sense; a system of equations (would eigenvectors have any meaning?).