Passwordless Authentication

Frictionless Proof of Presence

Passwordless authentication eliminates the most significant vulnerability in modern digital systems: the shared secret. By removing the need for a user to remember and transmit a password, we eliminate credential phishing, brute-force attacks, and password fatigue in a single strategic shift. Passwordless systems rely on cryptographic proof of possession or biological proof of inherence to verify identity with unparalleled certainty.

PASSWORDLESS

Eliminating Secrets

Core Mission

Removal of Knowledge Factors. Transitioning authentication from something the user remembers to something the user possesses or is, creating a "low-friction, high-assurance" experience.

Like a Modern Valet: You don't give the valet a secret code or a key that can be copied. Instead, your car detects your phone's unique cryptographic signal as you walk up and unlocks automatically. The car knows it's you because you possess the registered device, not because you remembered a number.

Consumer Apps / Mobile-First / Workforce Security

The Passwordless Landscape

Implementing passwordless requires choosing a pattern that balances security assurance with the realities of your user’s hardware and connectivity.

Strategic Method Comparison

Method	Assurance Level	Phishing Resistance	User Experience
Passkeys (FIDO2)	Highest	Full	Seamless (Biometric)
Magic Links	Medium	No (Email based)	Low (Context switch)
SMS/Push OTP	Medium	Low (Interception)	Medium (Code entry)
Hardware Keys	High	Full	Physical (Plugin/Tap)

The Passwordless Handshake

Modern passwordless flows (like Passkeys) utilize public-key cryptography to ensure that no secrets are ever shared with the server.

1

Identify

The user provides their identifier (e.g., email or username). The server looks up registered public keys for that identity.

2

Challenge

The server sends a cryptographic challenge to the user's device. The device prompts for a local biometric (FaceID/TouchID) or PIN to unlock the private key.

3

Verify

The device signs the challenge and returns it. The server verifies the signature using the stored public key and establishes the session.

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Technical Passwordless Pattern Guides

Implement the future of authentication with these specialized technical guides.

Passkeys (FIDO2)

Implementation of the high-assurance standard for multi-device, synchronizable credentials.

Biometric Inherence

Using platform builders like Apple's Secure Enclave and Android's Keystore for authentication.

Persistent Trust

Managing long-lived trust on registered devices while forcing re-auth for sensitive actions.

Device Integrity

Verifying the health and security posture of the device used for passwordless login.

Next Steps

• Explore WebAuthn UX for best practices in designing passwordless registration.
• Review Fallback Strategies for users who lose access to their primary device.
• Check Passkey Readiness to see browser and OS support.