Matching a face to a verified record is a powerful check — but only if the face is real and present. Hold up a printed photo, replay a video on a phone, or present a mask, and a naive face match can be fooled. Liveness detection is the layer that tells a live human apart from a spoof, and it's what makes face-based entry trustworthy.
The problem liveness solves
Face recognition answers 'does this face match the record?' It does not, on its own, answer 'is this an actual person standing here right now?' Presentation attacks exploit exactly that gap:
- Print attacks — a photo of the target held up to the camera.
- Replay attacks — a video or photo played on a screen.
- Mask or 3D attacks — a physical or digital face stand-in.
How liveness detection works
Liveness checks look for the signals a flat image or replay can't reproduce — natural texture, depth, micro-movement and the way a real face responds to the camera. Approaches fall into two broad families:
- Passive liveness — analyses a single capture in the background, with nothing extra asked of the visitor. Fastest and least intrusive.
- Active liveness — prompts a simple action (a blink, a turn) to confirm a live subject. More friction, sometimes used for higher assurance.
Where it fits in the check
Liveness doesn't stand alone — it strengthens the face match that ties a person to their verified identity. The flow is: verify the credential (Aadhaar or DigiLocker), capture a live selfie with a liveness check, then match that selfie to the photo in the signed record. Liveness stops the credential from being used with a borrowed or fake face. See how the face-match step works in face authentication for entry.
Privacy still applies
A face image is personal — and, depending on how it's processed, potentially sensitive — data. Liveness should be consent-based and purpose-limited: used to confirm the visit, not to build a face database. Combined with never storing the full Aadhaar number (Aadhaar masking), it fits the expectations of the DPDP Act. Confirm your own obligations before deploying biometric checks.
Liveness in Certopact Entry
Live Face in Certopact Entry matches a live selfie to the photo in the verified record as part of Aadhaar visitor verification — so a genuine credential can't simply be borrowed. This is general information, not legal advice.