A control objective is
|“||a statement of intent with respect to control over some aspect of an organization's resources or processes.||”|
In terms of a computer system, control objectives provide a framework for developing a strategy for fulfilling a set of security requirements. In particular, a given system can only be said to be secure with respect to its enforcement of some specific policy. The control objective for security policy is as follows:
|“||The security policy is a statement of intent with regard to control over access to, dissemination of, and modification of information. The security policy must be precisely defined and implemented for each system that is used to process sensitive information. The security policy must accurately reflect the laws, regulations, and general policies from which it is derived.||”|
Discretionary control is the most common type of access control mechanism implemented in computer systems today. The basis of this kind of security is that an individual user, or program operating on the user's behalf, is allowed to specify explicitly the types of access other users (or programs executing on their behalf) may have to information under the user's control. Discretionary security differs from mandatory security in that it implements the access control decisions of the user. Mandatory controls are driven by the results of a comparison between the user's trust level or clearance and the sensitivity designation of the information.
- Overview section: A Guide to Understanding Discretionary Access Control in Trusted Systems, at 1.