Key custody and biometrics — who holds your keys?

PTERI is zero-custody: private keys are generated on your device, protected by biometrics (FIDO2), stored in hardware-backed storage when available, and never leave the device.

Kakr Labs' infrastructure can verify your signatures but cannot impersonate you and cannot recover your keys. This is why verification is deterministic: either the correct key signed the action, or it didn't.

Why determinism matters

Traditional security is probabilistic — risk scores, heuristics, "suspicious login" guesses. PTERI verification is deterministic cryptographic proof at action time, which removes whole classes of false positives and social-engineering attacks.