What is an Access Control List?

• A. A register of: 1. users (including groups, machines, processes) who have been given permission to use a particular system resource and 2. the types of access they have been permitted.
• B. A list of authorized encryption keys.
• C. A schedule of system maintenance windows.
• D. A catalog of software licenses.

Answer: (A)

An Access Control List is a mechanism that defines who can access a resource and what actions they may perform. It attaches to the resource and contains entries for principals—such as individual users, groups, machines, or processes—along with the specific permissions granted (like read, write, execute, or delete). This lets the system quickly determine whether a requested action should be allowed or denied by consulting the list.

This concept is not about cryptographic keys, so it isn’t a record of authorized encryption keys. It isn’t a schedule of when maintenance occurs, nor a catalog of software licenses. Those items serve different purposes in security, operations, and asset management.