Passkey

A passkey is a phishing-resistant sign-in credential based on public-key cryptography, with the private credential protected by a user device or provider.

The service stores a public key, while authentication requires the corresponding private key and typically a local device unlock such as a PIN or biometric. Because the credential is bound to the legitimate site, a fake domain cannot simply collect a reusable secret. Security still depends on device protection, account recovery, synchronization arrangements, and prompt removal of access from lost or untrusted devices.