There's an increasing recognition that passwords alone are not going be an adequate form of online security in the future. Two-factor authentication can vastly improve security, by simply introducing a second means of verification alongside a password. Google's new USB Security Key does just that.
There are various possible alternatives to using passwords or passwords alone for security. Google already offers a number of different two-step methods. Users can be sent codes via text message or phone call to input in addition to their password, they can generate a code via a mobile app, use back-up one-time-use codes or register a regularly-used computer or device as a second means of verification.
Google says that the Security Key pairs with its Chrome browser to offer even stronger security than its existing methods. It is also more convenient. Users simply insert the key into a USB port on their computer and press a button on it when prompted.
In addition to providing a second means of authentication, the key also verifies that the site requesting the password is actually a Google site and not a fake. As it is a USB key, the device is highly portable and avoids the need to rely on receiving codes or even having mobile connectivity available.
The Security Key uses the FIDO Alliance's open Universal 2nd Factor (U2F) protocol, which utilizes a standard public key cryptography approach. FIDO U2F will work with other websites as well as Google's and the company says that, in the interests of standardization, it hopes other browsers will add FIDO U2F support.
Source: Google