In biometric systems, a false acceptance occurs when an imposter is granted access.

• A. True
• B. False
• C. Not sure
• D. Both

Answer: (A)

In biometric systems, a false acceptance occurs when an imposter is granted access. This is described by the false acceptance rate, the likelihood that an unauthorized biometric sample is incorrectly matched to a legitimate enrolled identity. Decisions are based on a similarity score versus a threshold; if the threshold is too permissive, imposters slip through, increasing false acceptance, while a very strict threshold can cause legitimate users to be rejected. To reduce this risk, designers improve sensor quality, use multi-factor authentication, and implement anti-spoofing and liveness checks.