Which biometric method is commonly used for door access?

• A. Fingerprint
• B. Iris
• C. Hand geometry
• D. Voice

Answer: (C)

Biometric door access systems favor methods that are fast, reliable, and cost-effective. Hand geometry reads the size and shape of the hand—the lengths and widths of the fingers, palm, and overall hand dimensions—rather than skin patterns or iris details. This makes enrollment quick and the sensors robust, which is ideal for throughput in entry points and for environments where lighting or conditions vary. Because it relies on overall hand measurements, it’s less sensitive to dirt, wear, or moisture on the fingers than a fingerprint reader and doesn’t require the high-cost hardware and controlled conditions some other biometrics need. These practical advantages have kept hand geometry widely used for door access. In comparison, fingerprint readers can struggle with dirty or worn fingers, iris or facial systems demand more expensive sensors and controlled conditions, and voice recognition can be unreliable in noisy or distant-entry scenarios.