- Reference Monitor and Security Kernel:
- Reference Monitor: A component that enforces access control policies by determining whether a subject (e.g., a user or process) should be allowed to access an object (e.g., a file or resource). It is responsible for ensuring that all access attempts are checked against the security policy.
- Security Kernel: The hardware, firmware, and software components that implement the reference monitor function. It provides the necessary mechanisms to enforce access control decisions made by the reference monitor.
- Complete Mediation:
- Definition: A principle stating that every access to every object must be checked to ensure that the subject has the necessary authorization. This means that all subjects must be authenticated and their access rights verified before they can access any object, ensuring that unauthorized access is prevented.
These concepts are fundamental to enforcing security policies and ensuring that only authorized users and processes can access protected resources.