MFA

FIDO with a YubiKey is phishing-resistant and avoids transferable SMS codes. Total security also depends on configuration and recovery processes.

That depends on the protocol. FIDO with a YubiKey is phishing-resistant, while manually entered TOTP codes can be intercepted; apps that use FIDO themselves have different characteristics.

Use a pre-registered backup key or the service's recovery procedure and revoke the lost key as soon as possible. A hardware-bound passkey cannot be copied.

Yubico recommends registering at least one backup YubiKey with accounts. Store it separately and securely and periodically check the recovery process.

Yes, when the accounts support the protocol. Consider model- and firmware-dependent capacity for stored passkeys and other credentials.