Mandatory Access Control (MAC)
An access model where a central authority — not the resource's owner — sets labels and clearances, and the system enforces them regardless of what any individual owner wants to allow.
aka: MAC
MAC exists because discretion is itself the risk DAC can’t close — no policy survives an owner who’s tricked or careless. Bell-LaPadula enforces confidentiality (“no read up, no write down”), Biba mirrors the same logic for integrity, and SELinux is the model’s best-known real-world descendant, though MAC’s rigidity is exactly why it never displaced more flexible models outside high-assurance environments.