WebAuthn Passkey Engineer

Expert guidance for implementing passwordless authentication with WebAuthn passkeys — covering registration/authentication ceremonies, platform vs roaming authenticators, cross-device flows, conditional UI, and migration from passwords to phishing-resistant credentials.

Gold

v1.0.00 activationsSecurityEngineeringadvanced

SupaScore

84.6

Research Quality (15%)

8.5

Prompt Engineering (25%)

8.7

Practical Utility (15%)

8.4

Completeness (10%)

8.3

User Satisfaction (20%)

8.3

Decision Usefulness (15%)

8.4

Best for

▸Implementing WebAuthn passkey registration and authentication flows in web applications
▸Migrating existing password-based authentication to support passkeys while maintaining fallback options
▸Designing cross-device authentication flows using FIDO2 hybrid transport with QR codes
▸Configuring conditional UI for username-less login with resident keys
▸Troubleshooting passkey implementation issues across different browsers and platforms

What you'll get

●Detailed code implementation for WebAuthn registration ceremony with proper challenge generation, credential options configuration, and server-side validation steps
●Cross-platform deployment strategy covering browser support matrices, platform authenticator capabilities, and fallback authentication methods
●Security architecture recommendations for credential storage, user verification requirements, and attestation validation policies

Not designed for ↓

×General OAuth/SAML identity provider integration or enterprise SSO setup
×Mobile app biometric authentication without WebAuthn (native Touch ID/Face ID only)
×Password manager development or browser extension security
×Smart card or traditional PKI certificate authentication systems

Expects

Details about your current authentication stack, target platforms, user base type (consumer/enterprise), and specific WebAuthn implementation challenges or requirements.

Returns

Step-by-step implementation guidance, code examples for registration/authentication ceremonies, security configuration recommendations, and troubleshooting solutions for cross-platform passkey deployment.

Evidence Policy

Enabled: this skill cites sources and distinguishes evidence from opinion.

webauthnpasskeysfido2passwordlessauthenticationbiometricssecurity-keysphishing-resistantconditional-uictap2zero-trustidentity

Research Foundation: 7 sources (4 official docs, 2 web, 1 industry frameworks)

This skill was developed through independent research and synthesis. SupaSkills is not affiliated with or endorsed by any cited author or organisation.

Version History

v1.0.02/16/2026

Initial release

Works well with

API Security HardenerGold Authentication & Authorization ArchitectGold Mobile App Security AuditorPlatinum OAuth Hardening SpecialistGold Zero Trust Access PatternsGold

Need more depth?

Specialist skills that go deeper in areas this skill touches.

Cryptography Implementation AdvisorGold Identity Governance ArchitectGold Penetration Testing GuideGold

Common Workflows

Secure Authentication Modernization

Complete migration from legacy authentication to passwordless with comprehensive access controls and governance

webauthn-passkey-engineer→Zero Trust Access Patterns→Identity Governance Architect

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