The next time you use your Apple ID to buy something from the App Store or iTunes or sign into your Apple account or iCloud storage, think what would happen if the bad guys had your password. If that's a frightening thought, you can beef up your account with two-factor authentication.
Launched in 2015 with iOS 9 as an upgrade to the two-step verification Apple launched in 2013, two-factor authentication requires you to sign in with your Apple account password and a numeric verification code that's generated on the fly. You'll receive your verification code via a text message or phone call on a device that's already been authenticated.
For example, if you want to purchase an item through your iPad, the code could pop up on your already-authenticated iPhone. This type of protection may sound cumbersome. But you only have to do it once for your Apple devices after the authentication is enabled (unless you sign out, erase the device, or need to change your password, Apple says). Future attempts to access your Apple account or log in to buy an app or other item will require just your password.
The process creates a trusted relationship between an Apple device and your Apple ID, thus adding that extra layer of security. Two-factor authentication is available to iCloud users with at least one mobile device that runs iOS 9+ or a Mac with OS X El Capitan or later. Let's go through the steps for enabling two-factor authentication on your Apple mobile device and account.
Turn On Two-Factor Authentication
Fire up your iPhone or iPad. Go to Settings > iCloud. On your mobile device, tap your Apple ID at the top of the iCloud screen.
Enter your Apple password if requested. At the Apple ID screen, tap the setting for Password & Security.
At the Password & Security screen, tap the option to "Turn on Two-Factor Authentication."
An Apple ID Security screen pops. Click the Continue link.
At the Phone Number screen, enter your mobile phone number if it doesn't already appear. If you're setting this up on your iPhone, you'll also see an option asking if you want to receive the verification code via text message or phone call. If you're setting it up on your iPad, your only choice is to receive it by text message. Let's pick text message. Click Next, or click on the Continue link.
You're asked again to sign in with your Apple ID password.
Two-factor authentication is now turned on.
The next time you try to access your Apple account on a different device, you'll receive an Apple Sign In request on your initially authenticated device with an approximate location. (Don't worry if the location isn't anywhere near you; it's based more on IP address and network factors than physical locale). Click Allow.
A six-digit numerical verification code then pops up. Enter that code on the device from which you're trying to access your Apple account. You'll now be able to access your account, your iCloud content and settings, and any App Store or iTunes content you wish to purchase.
Turn Off Two-Factor Authentication
Given how much data is stored on your Apple account, two-factor authentication is a good idea. But if it becomes too much of a hassle, you can deactivate it. Sign in to your Apple account online via appleid.apple.com. Scroll down to Security > Two-Factor Authentication and click "Turn Off Two-Factor Authentication."