The new security measure means that if you have two-step verification enabled, the next time you try to login to iMessage or FaceTime on a new device you will have to supply a code sent to your smartphone via text message in addition to logging in with your password. Apple's version of two-factor authentication does not work with authenticator smartphone apps.
The impact on you at home: After the so-called celebrity iCloud hacks in August, security measures for Apple services were criticized for not being strong enough. Apple first improved security last September when it extended two-step verification measures to protect iCloud backups. Extending two-step verification to your personal messages on FaceTime and iMessage is an excellent extension of Apple's ongoing security efforts.
Getting started
If you've never enabled two-step verification, setting it up is easy. Just visit My Apple ID, sign in and under Password and Security choose to enable two-step verification at the top of the page.
Apple will then lead you through a short set-up that will include setting up your smartphone to receive two-step verification codes. You will also receive a back-up recovery key (a long code made up of numbers and letters) that you can use to sign-in to Apple services should you lose access to your phone.
When you sign-up for two-step verification be sure to read through each step carefully. Apple warns that once two-step verification is enabled your security questions will no longer be used to verify your identity.
To gain access to your Apple account, then, you'll need two out of the following three items: your Apple ID password, the trusted device where you receive SMS codes from Apple, or your recovery key.