High Quality Content by WIKIPEDIA articles! Security policy is a definition of what it means to be secure for a system, organization or other entity. For an organization, it addresses the constraints on behavior of its members as well as constraints imposed on adversaries by mechanisms such as doors, locks, keys and walls. For systems, the security policy addresses constraints on functions and flow among them, constraints on access by external systems and adversaries including programs and access to data by people. Because the security policy is a high level definition of secure behavior, it is meaningless to claim an entity is "secure" without knowing what "secure" means. It is also foolish to make any significant effort to address security without tracing the effort to a security policy.