If you have already enabled two-step authentication via SMS or a two-step mobile app, you have the additional option of adding one or more FIDO U2F security keys. Security keys are devices that connect to your computer via USB, Bluetooth, or NFC, and provide an additional form of two-step authentication.
If you have not yet done so, first set up two-step authentication by SMS or mobile app.
In your Profile settings under the Two-step Authentication section, click Add.
Select Add security key.
When prompted, plug in and tap your security key.
Next, enter a name for your security key. This will help you tell them apart if you add multiple security keys.
Similar to the other methods, we will require this key for any new devices, as well as periodically to confirm the device is still yours.
FIDO U2F is only compatible with certain web browsers.