The alert hits your dashboard at 02:17. No passwords were stolen, because your system doesn’t use them. But something is wrong. A session token is acting out of pattern.
Passwordless authentication changes the rules of incident response. You are no longer looking for brute-force password attempts. You are hunting compromised devices, stolen WebAuthn credentials, misused magic links, and replayed authentication tokens. The threat surface shifts from password databases to trust validation endpoints, signing keys, and identity providers.
When a breach occurs in a passwordless system, speed and signal clarity matter. Your incident response workflow should start by identifying anomalous authentication requests—based on IP, device fingerprint, and time series comparison against historical user behavior. If you use passkeys or hardware tokens, audit the logs for failed attestation checks or sudden key deregistration events. For services relying on one-time links or codes, inspect expiration timestamps and link distribution channels.
Containment in this ecosystem means killing active sessions instantly and rotating any signing keys involved. In systems with federated or delegated identity, force re-authentication at the IdP and revalidate stored credentials with cryptographic integrity checks. Session revocation and key rotation must happen across every microservice, not just the authentication gateway.