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Hardware & Device Attestation

Biometric verification is only as strong as the device that performed it. A rooted phone running a tampered app can fake a “verified” result — so VEID pairs every biometric capture with device integrity attestation.

Supported platforms

Section titled “Supported platforms”
  • Play Integrity API (primary) — device integrity and strong integrity verdicts.
  • SafetyNet Attestation — fallback for legacy devices.
  • Supported sensors: fingerprint (optical, capacitive, ultrasonic) and iris where the OEM hardware supports it.

How attestation fits the pipeline

Section titled “How attestation fits the pipeline”

During enrollment, after biometric hardware capture:

  1. The app requests an attestation token from the platform (Play Integrity / App Attest).
  2. The token is verified — proving the app is genuine, unmodified, and running on hardware that meets integrity requirements.
  3. The attestation payload is encrypted into the vault alongside the biometric templates.
  4. On-chain scopes of type biometric_hardware and device_attestation are created, referencing the encrypted payloads.
  5. The verification attestation references those scope IDs, making the whole chain of evidence auditable without exposing any of the underlying data.

Fallback behavior

Section titled “Fallback behavior”

Not every device supports attestation APIs. VEID’s policy is explicit degradation rather than silent failure:

  • If the platform cannot attest, the capture flow continues, but the device_attestation scope is marked as unsupported.
  • Verification pipelines should enforce attestation-required policies for high-risk actions (validator onboarding is the canonical example) and may allow fallback for low-risk flows.

Relying parties therefore always know which assurance level a given identity actually carries.

Privacy commitments

Section titled “Privacy commitments”

The attestation subsystem follows the same rules as the rest of VEID (see Privacy Model):

  • Data minimization — only templates and integrity metadata required for verification are stored.
  • Encryption — all biometric templates and attestation payloads are encrypted with the VEID envelope before storage.
  • Consent — biometric capture requires explicit consent under the Biometric Data Addendum.
  • Retention — attestation payloads follow VEID lifecycle policies (expiration and revocation).
  • Auditability — attestation failures are recorded on-chain for review and dispute handling.