security function

A discrete aspect of the performance of a system by which it enforces security automatically on behalf of the System Manager and /or system users [CESG]. Note: [1] Access control, authentication, accounting and audit are defined as major security functions which can be broken down into “functional elements”. [2] The term is normally used at the requirements stage of a system life cycle, a System Electronic Information Security policy. See also: Mechanism, Trusted Function.