Veterans Affairs - What happens when I select "FIDO U2F Security Key" for MFA? A FIDO U2F Security Key uses a specialized USB device to help secure your account with multi-factor authentication (MFA). Related articles How do I set up "FIDO Security Key" multi-factor authentication? Veterans Affairs - What happens when I select "Mobile YubiKey" for MFA? Veterans Affairs - How do I verify my identity for Veterans Affairs? Veterans Affairs - What happens when I select "Code Generator" for MFA? How do I verify my identity using my Driver's License or State ID?