Google has announced the introduction of an improved two-factor authentication mechanism based on a USB token dubbed Security Key. The new 2FA process is based on the use of a tiny hardware token that will allow the authentication only when users visit legitimate Google sites. Security Key system initially will work only in Chrome, but according to Google it will be soon available for other browsers and with all the websites implementing the U2F protocol. Users can acquire the Security Key from popular retailers and also from Amazon.”]
Source: http://securityaffairs.co/wordpress/29479/hacking/google-2fa-security-key.html