discretionary access control

An access control service that (a) enforces a security policy based on the identity of system entities and the authorizations associated with the identities and (b) incorporates a concept of ownership in which access rights for a system resource may be granted and revoked by the entity that owns the resource. (See: access control list, DAC, identity-based security policy, mandatory access control.)

Derivation: This service is termed "discretionary" because an entity can be granted access rights to a resource such that the entity can by its own volition enable other entities to access the resource.

"A means of restricting access to objects based on the identity of subjects and/or groups to which they belong. The controls are discretionary in the sense that a subject with a certain access permission is capable of passing that permission (perhaps indirectly) on to any other subject." [DoD1]