What Security-in-Depth principle is illustrated by a vault with special controls to limit access to only some of the personnel that work within a secure facility?

• A. Enclaving
• B. Redundancy
• C. Access control
• D. Surveillance

Answer: (A)

Enclaving is the security-in-depth approach that isolates a valuable asset inside a protected zone with its own strict access controls. A vault serves as that enclave within the secure facility, and by applying special controls, access is granted only to a subset of personnel who are cleared for it. This creates an additional barrier; even if someone can enter the facility, they still must overcome the vault’s specific controls to reach the asset. This emphasis on containment and zone-specific protection distinguishes enclaving from broader concepts like redundancy (duplicating components for availability) and surveillance (monitoring activity), while recognizing that access control is part of the overall protection but the key idea here is isolating the asset in its own secure enclave.