Capture signals: how the level is set
At capture, Evidiq measures the signals listed below and seals their result with the proof, as an index from 0 to 100. The page of a validated proof shows only its level, in words.
The two levels shown
- strong
- Sealed index from 80 to 100.
- sufficient for validation
- Sealed index from the validation threshold the issuer chose, never below 60, up to 79.
- A proof that was not validated shows no level.
- The reachable level depends on the type of capture: a capture made in a web browser, for instance, cannot provide a device attestation.
- A signal not measured is final for that proof: nothing is added to it after sealing.
The signals measured
Cryptographic spine
- Device attestation (Google Play Integrity, Apple App Attest)
- Content provenance signature (C2PA)
- Capture audit-trail integrity
Spatio-temporal coherence
- Location consistency
- Timestamp freshness
- Cross-signal coherence
- Capture metadata
Media authenticity
- File integrity
- File-fingerprint uniqueness
- AI-generated image detection
- AI-generated video detection
Other signals
- Provenance signature of imported files (C2PA)
- Recapture analysis (screen or print)
- File encoding analysis
The cryptographic core carries most of the index; spatio-temporal coherence and media authenticity complete it. Exact weights are not published: making them public would tell fraudsters which signals to imitate first.
Bonus above the base
- Camera-sensor match (opt-in calibration)
- Video camera-sensor match (opt-in calibration)
This signal adds as a bonus when the opt-in sensor calibration confirms the device. Absent or inconclusive, it takes nothing away.