What is "Two Factor Authentication"?

On the heels of last Friday's post, we're going to continue our discussion of security. I know that normally today would be "Beginner Monday", but this is something that ALL users need to embrace - new, intermediate and advanced alike.

If you haven't already, please read Friday's post on passwords. We'll wait.

Done? Got it? Good. Moving on.

So what is a "factor"?

So, in terms of computer security (and most other security), there are three factors that govern security: 

• Something you know (username, password, passphrase, PIN, secret code)
• Something you have (decoder ring, security "dongle", smartphone, security badge, etc.)
• Something you are (fingerprint, retinal scan, dna scan)

All security falls into one or more of these three categories. How they're implemented changes, though.

So, my username and password - that's two-factor, right?

Wrong.

See, both your username and your password are something you know. That's one factor. Even though it's two separate things to know, they're both still something known. That makes it ONE factor authentication.

So how do I use this newfangled two-factor authentimication?

So, to use two-factor authentication, you need to use at least two of three categories. Due to the high cost of implementing the last one, most consumer systems stick to Something you Know, and Something you Have. The two biggest sites using this system are Google and Facebook (arguably the two richest internet companies in the world, and definitely the two most widely used by users).

So the first factor is easiest - something you know - your username and password. You probably already go this set up. The second factor is something you typically have to activate after registration. Most systems do not have this turned on by default. 

In Google, you need to go into your account settings, under "Security", and turn on 2-factor authentication. You will need a smart phone or at least one with text messaging, to work. There are alternative ways to make this work without one, you can read about them on Lifehacker.