Face Continuity Checks: Verifying Candidate Identity Without Storing Biometrics
Continuity, not recognition
There are two very different things you can do with a face during an interview:
- Recognition. Match the face to an external identity (a passport, a database). This requires enrolling a biometric template — a serious privacy and compliance commitment.
- Continuity. Check that the same face is present from minute one to minute fifty. No identity database, no enrollment.
For most hiring use cases, you only need #2. ClarityHire is built around continuity: we never store biometric identifiers, and we never match candidates against a recognition database.
What continuity actually catches
- A candidate hands their laptop to a friend mid-interview.
- A different person joins the call after a "bathroom break."
- Two faces appear on camera simultaneously (someone reading the screen).
- The candidate disappears from frame for extended periods.
That is enough to deter the overwhelming majority of impersonation attempts, which are opportunistic rather than sophisticated.
How it works under the hood
A lightweight face-detection model runs locally and emits a per-frame embedding. We compare consecutive embeddings to a moving baseline and flag changes — not identities. The embeddings themselves are not retained beyond the session, and they are never used to identify the candidate.
This design has a useful side effect: it is jurisdiction-agnostic. There is no biometric "template" under most legal definitions, so deployment in regions with strict biometric laws (Illinois BIPA, EU GDPR Article 9) is dramatically simpler.
Combining it with other signals
Continuity alone has blind spots — a determined cheater can keep the right face in frame while taking instructions through an earbud. That is why we pair face continuity with audio analysis (off-camera voice detection), keystroke biometrics, and screen-share anomaly detection. No single signal is conclusive; the combination is.
What to tell candidates
Plain language, in the invite email: "We use camera-based continuity checks to confirm the same person is taking the test from start to finish. We do not perform facial recognition and we do not store biometric identifiers." Most candidates appreciate the directness.