ELI5: What is Passwordless Authentication?
Instead of remembering a password that someone could guess or steal, you log in with your fingerprint, your face, or a special key you carry. There’s no password to steal because there is no password at all.
Definition
Passwordless authentication eliminates the use of shared secrets (passwords) for user authentication, replacing them with cryptographic methods that are phishing-resistant and not vulnerable to credential theft, brute-force, or password reuse attacks. The primary standards are FIDO2 and WebAuthn, which use public-key cryptography with hardware authenticators or device biometrics (“passkeys”).
Key Details
- FIDO2/WebAuthn: The authenticator generates a public/private key pair for each service; the private key never leaves the device; authentication proves possession of the private key.
- Passkeys: Device-bound or synced FIDO2 credentials—can be backed up across devices via iCloud/Google Password Manager while maintaining phishing resistance.
- Inherently phishing-resistant: The credential is bound to the specific website’s origin—cannot be used on a lookalike phishing site.
- Eliminates: password brute-force, credential stuffing, password spraying, password reuse, phishing for passwords.
- Being adopted by major platforms: Windows Hello, Apple Face ID/Touch ID, Google passkeys, hardware security keys (YubiKey).
Connections
- Parent: authentication — the future of authentication
- See also: certificate-based-authentication