Two-factor authentication: Everything you need to know!

Hackers are too good, and security systems flawed. Longer complicated passwords created by generators like Safari's iCloud Keychain or third party apps like LastPass or 1Password can help, but the best way to lock down your accounts is to add extra security options for two-step or two-factor (2FA) authentication. Here's how to go about it.

• How to set up two-factor for Apple and iCloud
• How to set up two-factor for Google and Gmail
• How to set up two-factor for Dropbox
• How to set up two-factor for Amazon
• How to set up two-factor for Twitter
• How to set up two-factor for Facebook
• How to set up two-factor for Instagram
• How to se up two-factor for Tumblr
• How to set up two-factor for Skype
• How to set up two-factor for Nest
• How to use Authy to manage two-factor

What is two-factor authentication?

Two-factor authentication is the most prevalent way to secure your accounts: It asks you to authenticate that you are who you say you are by supplying not only your password, but a unique code supplied from your phone or an external app. It ensures that those accessing your accounts have access to your physical devices as well as your virtual passwords, and makes a simple password crack or social engineering hack a lot more insufficient when it comes to accessing your personal data.

What's the difference between two-factor authentication and two-step verification?

They're commonly used interchangeably, but two-factor traditionally requires two different types of authentication. That can include something you know (password), something your are (fingerprint), or something you have (Bluetooth dongle). Two-step verification, on the other hand, can use the same type of information delivered by different sources. For example, a code you remember (password) plus a code you're sent over SMS (token).

Two (or more) factors can be more secure, but two steps are typically enough for most online accounts. It's a better version of the old "security questions". It not only helps you avoid needing to remember your random answers, but it also removes the risk of relying on potentially easy-to-find information.

Why is two-factor authentication so important?

Passwords are weak, broken, and by all accounts, outdated: Having to remember a random assortment of numbers, letters, and possibly (but not always) other characters can be tough on your memory and easy for attackers to compromise, especially when technology like Touch ID exists. Apps like 1Password or LastPass can help with organizing and memorizing your passwords and even help you create super-long strings, but you're still reliant on a single password to keep you safe. Two-step/two-factor authentication requires two different keys to log you into your account, significantly amping up the level of difficulty for any would-be hackers to access your personal information.

What accounts can I set up with two-step verification or two-factor authentication?

Over the past few years, lots of web services and banks have hopped aboard the multiple authentication methods bandwagon — more than we can properly list. The folks over at Two Factor Auth, however, have kindly put together a master list of services that support two-step verification or two-factor authentication, along with links to how-to documents, what methods of two-factor authentication they support, and how to contact a service you use to request that they implement two-factor authentication.

Here at iMore, we've put together a bunch of articles on some of the most popular services that support two-step/two-factor authentication — as well as the easiest ways to set it up — to help you keep your accounts safe and away from prying eyes.

• How to set up two-factor for Apple and iCloud
• How to set up two-factor for Google and Gmail
• How to set up two-factor for Dropbox
• How to set up two-factor for Amazon
• How to set up two-factor for Twitter
• How to set up two-factor for Facebook
• How to set up two-factor for Instagram
• How to se up two-factor for Tumblr
• How to set up two-factor for Skype
• How to set up two-factor for Nest
• How to use Authy to manage two-factor

What if I lose my phone (or have it stolen)?

One of the big fears with SMS or code-based two-factor authentication is the potential loss of your primary authentication device: If you don't have your phone, you can't get SMS messages, et cetera. Thankfully, most services offer recovery keys or special passcodes that can unlock your account in case you don't have access to your cell phone at the present moment. Make sure to write these down in a safe place; I use 1Password's secure notes feature for this, and also store a hard copy in my office.

Need more help with two-step verification or two-factor authentication?

Running into trouble setting up two-step verification or two-factor authentication? Have a question about turning two-step or two-factor on for your favorite service? The iMore Forums are a great place to get advice and help from other members of our community; you can also ask a question in our Q&A forum and we'll get back to you as soon as we can.