Which option best describes a layered access control approach in a facility?

• A. A single badge reader at the main entrance.
• B. CCTV surveillance used as the sole control.
• C. Badges, biometrics, guards, and physical barriers at multiple entry points.
• D. No physical controls, only policies.

Answer: (C)

A layered access control approach uses multiple protective measures at different points and levels to prevent unauthorized entry. This relies on defense in depth: if one control is bypassed, others still stand to stop or detect intruders. Putting badges, biometrics, guards, and physical barriers at several entry points creates redundancy and makes it much harder for someone to slip through unnoticed. Badges confirm identity, biometrics add a second factor, guards provide real-time verification and intervention, and physical barriers like turnstiles, doors, and fences slow movement and direct it through controlled channels. When these controls are applied across multiple doors or zones, an individual must meet several criteria—often in sequence—to gain access, which reduces the chance of a single compromised credential or weak point leading to a breach.

This approach is superior to relying on a single measure, such as one badge reader, CCTV used as the sole control, or no physical controls at all and only policies. A lone badge can be stolen or misused; surveillance alone doesn’t prevent entry; policies without physical barriers leave doors open to tampering. By layering checks and separating duties across entry points, the facility gains better protection, faster detection, and clearer accountability.