Add a Security Key to your Google Account - Accounts Help. Where possible, I use two step authentication for website access. Someone would have to have physical possession of my phone to sign in to Google, for instance. Now, I have added another layer of protection, with the addition of a Plug-UP USB Security key, which requires physical possession of the key to access my account. Any website supporting the FIDO UDF protocol can be set up for the key. Are you safe today?