Complete Mediation

Definition: Complete mediation is a security principle stating that every access to every resource must be checked for authorization. This ensures that no user or process can bypass security controls, preventing unauthorized access to system resources or data.

Context/Example: In a web application, complete mediation means that even after a user logs in, each request to access a file, database record, or functionality is checked against their permissions. For instance, a user with read-only access cannot exploit cached credentials or previously granted access to perform write operations.

Related Concepts: Access Control, Authorization, Security Principles, Least Privilege, Security Checks, Reference Monitor, Computer Security