FIDO2 PHISHING RESISTANCE properties + the channel binding + anti-replay + privacy mechanisms. PHISHING RESISTANCE: WebAuthn ceremonies bind the authentication to the ORIGIN (cryptographically verified by the client + RP server); a phishing site at evil.example.com cannot complete a WebAuthn assertion for legitimate.example.com - the browser + authenticator refuse the binding. NIST SP 800-63B Section 5.2.5 + the 2024 OMB M-22-09 + ZTA strategy mandate phishing-resistant authentication for high-impact federal systems + recommend FIDO2 + PIV/CAC. CHANNEL BINDING (legacy via Token Binding RFC 8471/8472, now deprecated) bound the assertion to the TLS channel preventing relay; the current model relies on origin binding + clientDataJSON inclusion in the signed authenticatorData + clientDataHash. ANTI-REPLAY: challenge-based per ceremony + signature counter (signCount monotonic) + anti-replay timestamping (RP issues + tracks challenge nonces with TTL + binds to client + session). CLONE DETECTION: signCount monotonic; lower-than-stored counter indicates a cloned authenticator + the credential MUST be revoked or step-up triggered. PRIVACY: AAGUID + attestation are anonymised (per-batch); discoverable credentials use opaque user-handle not user-identifying; cross-site tracking is prevented by per-RP-ID credential scoping (no global identifier); enterprise attestation is the explicit privacy-degraded exception for managed deployments.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.