DAC, Discretionary Access Control

In the field of computer security, discretionary access control is a means of limiting access to resources based on the identity of the subjects or groups they belong to. This permission can be viewed as discretionary since a subject with specific access is capable of passing that permission on to another subject. When in practice, DAC is not as well defined. For instance, it is often used in contexts that assumes every object to have an owner that manages access control. This is because many systems do implement DAC with the concept of object ownership. While this holds true in many situations, DAC does not necessarily have to be related to the concept of ownership. DAC is perhaps more clearly defined when contrasted to (MAC) mandatory access control. At times, a system in it’s entirety is said to have discretionary control, another way of saying that it lacks mandatory access control.