Apple has rolled out a new two-step verification service for iCloud and Apple ID users, reports “9to5Mac” (www.9to5Mac.com). This functionality greatly enhances the security of Apple accounts because it requires users to use a trusted device and an extra security code.
This security code can be sent via SMS or via the Find my iPhone iOS app (if it is installed). Users can now setup two-step authentication on their devices via the Apple ID website. Users need to access the security tab on this website to conduct the setup process.
Read more at http://support.apple.com/kb/HT5570 .