Safe alternative to code

An ingenious solution to be using a password or code to log in addition to the "normal" login with a "key".
The FIDO U2F Security Key is a solution that works via USB. Instead a code taking the keys to log in to Google.
Thus, the annoying remember a code is no longer necessary. You only need to insert the key into your USB port when you are prompted.
Furthermore, in my opinion, the FIDO U2F Security Key offers significant benefits, such as significantly better protection against phishing, as well as the Key without batteries or data connection works.
Unfortunately supported until now only the Chrome browser the Key. It is also a useful, of course not compatible due to the necessary USB port with mobile devices. Nevertheless, I am convinced of the product.