access control

"Access control refers to methods for controlling user access to networks. These methods may include login passwords, time, and computer restrictions. Access control ensures that content is accessed only by those entities authorized to do so, and only in a manner for which they have been authorized. Primarily, an access control system has three parts: signal scrambling, encryption of electronic keys which the viewer will need, and the subscriber management system. Access control systems may also be known as conditional access systems or customer access management systems. See also conditional access and encryption."