As we've said in the past, two-factor authentication is a fantastic way for users to add another layer of protection to their various online accounts... if you're using a service that provides it, you should take advantage of it. By implementing two-factor authentication whenever you can, you make it much more difficult for attackers and malware developers to compromise your digital lives. _
Image courtesy of [Ben Scholzen](http://www.flickr.com/photos/dasprid/8148007408/lightbox/).
_ One interesting bit of info with Github's introduction is that they are providing more than basic SMS-based two-factor authentication: they also support applications that provide a TOTP-based token.
TOTP is a time-based token that calculates your one-time password based on time. This means you can use applications like Google's Authenticator app (available for Android, iOS and Blackberry 10), Duo Mobile and Windows 7 Phone's Authenticator.
Wikipedia's article on TOTP goes into good detail on how it works.