With the third betas of iOS 9 and OS X 10.11 El Capitan, Apple is introducing a revamped two-factor authentication system, according to both the beta release notes and a detailed support FAQ that outlines the changes.
The new two-factor authentication system is different from Apple’s existing two-step verification system, using “different methods” to trust devices and deliver verification codes. Apple also says it includes a “more streamlined user experience.”
Based on the support document, the new two-factor authentication system works similarly to the existing two-step verification system. Any device that you sign into using two-factor authentication in iOS 9 or El Capitan becomes a trusted device that can be used to verify identify when signing into other devices or services linked to an Apple ID.
Apple recommends that iOS 9 and OS X El Capitan beta testers using the new two-factor authentication system update all of their devices to iOS 9 or El Capitan for “the best experience.” As outlined in the release notes, customers who use two-factor authentication with older devices may be required to use a six-digit verification code at the end of a password instead of in a dedicated verification field.
If you enable two-factor authentication, iTunes purchases on Mac and Windows will require you to append a 6-digit code to the end of your password on every purchase. The 6-digit code will automatically be sent to your iOS 9 or OS X El Capitan devices.
Older devices are also not able to receive two-factor authentication codes when used with devices running iOS 9 and El Capitan, but customers who stick with the older two-step verification system should not run into any issues as Apple tests the newer two-factor authentication system. Apple does not recommend that customers using two-step verification swap over to two-factor authentication until the feature is available to all.
First introduced in March of 2013, two-factor verification is an opt-in system that increases the security of Apple ID accounts. Since its debut, Apple has been woking to expand two-factor authentication to cover several different services like iCloud, iMessage, and FaceTime.
It is not entirely clear what other changes the new two-factor authentication system brings to iOS and Mac devices, but the switch to a new system may allow Apple to further extend the functionality of two-factor authentication in the future.