# Biometrics (FAR FRR CER)
One-sentence definition: Physiological/behavioral factors with measurable error rates for authentication.
## Key Facts
- Metrics: **FAR** (false accept), **FRR** (false reject), **CER/EER** (equal error rate).
- Template storage (not raw images); protect at rest/in transit.
- Liveness detection mitigates spoofing (masks, replays).
- Privacy and revocation limits (can’t “change” biometrics easily).
- Pair with possession factor for stronger MFA.
- **Verify:** check official (ISC)² CBK and current exam outline.
## Exam Relevance
- Choose lower CER for higher assurance; discuss privacy.
**Mnemonic:** “**Error** rates **expose** risk.”
## Mini Scenario
Q: High FRR causing lockouts—setting to adjust?
A: Relax matching threshold; monitor FAR trade-off.
## Revision Checklist
- Define FAR/FRR/CER.
- Template vs raw.
- Liveness purpose.
## Related
[[Authentication Factors and MFA]] · [[Passwordless and FIDO2 WebAuthn]] · [[Identity Proofing and Enrollment]] · [[Risk-Based and Adaptive Authentication]] · [[Privileged Access Management (PAM) and JIT JEA]] · [[Domain 5 - Index]]