Physical access control is a matter of who, where, and when.

More modern operating systems have the concept of access control.

And access control is desirable in order to prevent others from using the back door.

One form of access control is face (or another feature) recognition systems.

"From the scanners you see everywhere for physical access control and data security."

Examples of security services are key management, access control, and authentication.

Ambient authority is the dominant form of access control in computer systems today.

Improved building security and physical access controls offer some protection against theft.

The primary purpose of user groups is to simplify access control to computer systems.

Also, need-to-know principle needs to be in affect when talking about access control.