Final answer:
Controls access by comparing security labels with security clearances in Mandatory Access Control (MAC).
This system is designed to manage access permissions based on classified information and user security clearances. It's different from other access control models like Discretionary Access Control (DAC) and Role-Based Access Control (RBAC).
Step-by-step explanation:
The system that controls access based on comparing security labels with security clearances is Mandatory Access Control (MAC). In a MAC environment, access decisions are made by comparing the security labels (which might include classifications such as confidential, secret, or top secret) associated with resources to the security clearances of users.
For example, a user with a 'secret' clearance level would not be able to access resources labeled as 'top secret'. This is in contrast to Discretionary Access Control (DAC), where access is based on the resource owner's discretion, and Role-Based Access Control (RBAC), where access is based on the roles of individual users within an organization.
Lastly, Ruler-Based Access Control (RAC) refers to systems where access control decisions are taken based on rules defined by a central authority, but it is not commonly used as an acronym in the context of access control models.