Apple is eliminating its old two-step verification process and migrating all users to two-factor authentication with the roll out of iOS 11 and macOS High Sierra, according to an updated support document. The company rolled out two-factor authentication back in 2015, but the company had been letting people keep going with the older two-step authentication if they wanted. The two-step method requires logging in with an Apple ID and then sending a code to an Apple device via SMS text message, allowing users to require the added confirmation layer for things like signing into iCloud, tinkering with an Apple ID or buying things from iTunes, iBooks, or the App Store from a new device.
The system provided added security, but it wasn’t terribly smooth and left out Macs and other devices like the Apple TV, since the codes could only be sent to iOS devices. Apple has been encouraging users to switch to the two-factor authentication for a while now, with the new system already required for advanced features introduced a year ago, such as unlocking a Mac from an Apple Watch. With two-factor authorization, the Apple ID site is now just used to manage app-specific passwords for third-party apps.
Instead, an attempt to log in from a non-trusted machine or browser will send a location popup to every computer and iOS device associated with the iCloud account. Tapping “Allow” on that notification will display a six digit code that will allow you to proceed..