Dictionary · Defensive Security
Allowlisting
Design · Intermediate
Permitting only explicitly approved software, addresses, or actions and denying everything else. It is the reverse of trying to list everything bad.
A deny-by-default list ages better than a growing list of bad files, because new unwanted software is simply not on the approved list. It requires care so legitimate work is not blocked.
Example: A point-of-sale image runs only the approved payment application. A newly downloaded program cannot start.
Common misconception
- The older term blocklisting is the opposite approach. Allowlisting decides what is permitted, not what is forbidden.