FRR

How it works

• A lower number means fewer genuine users are locked out.
• It is traded off against the false acceptance rate, which counts the wrong people let in.
• Dirty sensors, injured fingers or poor lighting raise it.
• A backup way in, such as a PIN, covers the misses.

What can go wrong (example scenario)

A workshop switched its door lock to fingerprints. Staff with dusty or cut fingers were rejected every morning, and the owner ended up propping the door open.

• A fingerprint reader refuses a cleaner with worn fingertips.
• A face unlock fails when a staff member wears a mask.
• A laptop falls back to a PIN after three failed scans.

A question owners ask

What should I check before buying a biometric lock?

Ask how often it rejects genuine users and what the fallback is. A lock that people prop open protects nothing.