Security Is a Subset of Reliability

Reliability measures the deviation between the system and the specification. Security involves a subspace of reliability-only particular deviations-thus, security must be easier than reliability. Hastening over the delicate premise that the specification is always accurate and up-to-date, we can roughly align security with the subset of reliability where the cost of deviation per unit time is very high. This makes us wonder about measuring how risk tolerance scales and consequently where to point our our thumbs.