PasskeyWebAuthn

PasskeyWebAuthn is a term used to describe using passkeys with the Web Authentication API (WebAuthn) to provide passwordless authentication for online services. It is not an official separate standard, but rather a way to describe the combination of passkeys and WebAuthn. Passkeys are user-facing credentials that replace passwords with public key cryptography. In this model, the credential's private key remains on the user device in a secure authenticator, while the service stores only the corresponding public key and related metadata.

During registration, a service asks the browser to create a new WebAuthn credential; the authenticator generates a public-private key pair, the private key is kept secure, and the public key is registered with the service. Attestation may be provided to indicate the authenticator's characteristics. During sign-in, the service issues a cryptographic challenge; the authenticator signs it with the private key, and the browser forwards the signature for verification. A successful assertion authenticates the user without a password.

Passkeys are often synchronised across devices through platform services, such as cloud keychains. This enables sign-in on a different device after initial setup, while maintaining phishing resistance and defense against credential leaks. The WebAuthn protocol ensures origin binding and verifier checks, and supports user verification methods such as biometrics or PIN.

PasskeyWebAuthn relies on WebAuthn and CTAP2 as standards; major platforms support it, including Apple, Google, and Microsoft ecosystems. Limitations include varying browser support, reliance on compatible authenticators, and potential recovery challenges if devices are lost and cloud sync is unavailable. Overall, PasskeyWebAuthn represents a move toward phishing-resistant, passwordless authentication across the web.