None
A device or function designed to provide one or more security services usually rated in terms of strength of service and assurance of the design.
Source(s):
CNSSI 4009-2015
A method, tool, or procedure that is the realization of security requirements.
Note 1: A security mechanism exists in machine, technology, human, and physical forms.
Note 2: A security mechanism reflects security and trust principles.
Note 3: A security mechanism may enforce security policy and therefore must have capabilities consistent with the intent of the security policy.
Source(s):
NIST SP 800-160
[Superseded]