Passkeys / FIDO2 / WebAuthn

Passwordless authentication based on public-key cryptography, delivered through WebAuthn (W3C) and CTAP (FIDO).

Overview

Passkeys implement passwordless login using public-key cryptography. Users authenticate with a device-bound credential and local user verification (biometric or PIN), via the WebAuthn API and CTAP protocols.

How it works

  1. Registration: Site asks for a new credential via WebAuthn; an authenticator creates a key pair and returns a public key + attestation.
  2. Authentication: Site sends a challenge. Authenticator signs it with the private key after local user verification.
  3. Device portability: Platform sync or roaming authenticators (security keys) enable use across devices in line with vendor policies.

Common use cases

  • Consumer sign-in replacing passwords
  • Workforce phishing-resistant MFA
  • Step-up auth for high-risk transactions
  • Zero-trust endpoint access
  • Privileged-account and administrative access

Strengths and limitations

Strengths: Phishing resistance; no shared secrets; fast UX.
Limitations: Cross-ecosystem portability; attestation policy; account recovery patterns.

Key terms

  • WebAuthn: W3C API for creating/using credentials.
  • CTAP: FIDO protocol between client and authenticator.
  • Attestation: Evidence about the authenticator model/security.

Current market signal

Passkeys and FIDO credentials are expanding from consumer sign-in into national identity and enterprise authentication. Singpass adoption and Microsoft's Entra migration timeline show large identity platforms moving phishing-resistant credentials from an option toward a default.

References

Vendors using Passkeys / FIDO2 / WebAuthn

Latest Data Cards

  • Data Card

    Microsoft sets Entra passkey default and SMS retirement timeline

    2026-07-15CC-BY-4.0passkeys-webauthn

    Microsoft set a phased timeline to make passkeys the default Entra ID experience for users enabled for SMS or voice and to retire Microsoft-provided telecom authentication.

    • On September 1, 2026, in-scope users will be enabled and prompted to register passkeys.
    • Microsoft-provided SMS and voice delivery retires for public-cloud Entra ID on February 1, 2027.
    • Organizations with a continuing operational need can use a customer-managed telecom provider, while Microsoft recommends phishing-resistant methods as the primary path.
  • Data Card

    Singpass begins passkey rollout for national digital ID login

    2026-06-30CC-BY-4.0passkeys-webauthndigital-idmobile-id

    Singapore's GovTech began rolling out passkeys for Singpass, replacing phishable sign-in steps with cryptographic credentials unlocked by local device biometrics or a passcode.

    • The rollout began with eligible iOS users able to create a passkey from July 1, 2026.
    • The private key remains on the user's device while Singpass stores the corresponding public key.
    • Setting up Singpass on a replacement device automatically deactivates the app and passkey on the lost or previous device.
  • Data Card

    WebComm and ASUS launch FIDO-based Zero Trust PC for Thailand

    2026-06-24CC-BY-4.0passkeys-webauthndigital-id

    WebComm and ASUS introduced a FIDO-based Zero Trust PC for Thailand, tying device-level access controls to passwordless authentication and enterprise identity assurance.

    • The product positions FIDO authentication as a hardware-level control inside an enterprise endpoint.
    • The Zero Trust framing links device trust, identity verification, and secure access policy.
    • The launch reflects growing use of passkey and WebAuthn standards beyond consumer sign-in flows.

Frequently Asked Questions

What is a passkey?
A FIDO credential (public/private key pair) bound to a user and relying party. The private key stays on the device; the public key is registered with the service.
How is this phishing-resistant?
Credentials are origin-bound and never revealed; a signed challenge is produced locally after user verification (biometric or PIN).
CTAP vs WebAuthn?
WebAuthn is the browser API; CTAP connects clients to authenticators (platform or roaming security keys).
What’s the difference between multi-device and single-device passkeys?
Single-device credentials live only on one device; multi-device credentials can sync across an ecosystem under vendor security policies.
How do recoveries and device loss work?
RPs should provide recovery paths (additional authenticators, admin-recovery, or re-enrollment) while balancing phishing resistance and account takeover risks.