Apple has updated its Platform Security Guide, providing more information about how the Unlock with Apple Watch feature in iOS 14.5 and Touch ID on the iMac Magic Keyboard works.
The company routinely updates the security guide to incorporate information about new features. The Platform Security Guide contains detailed and in-depth information about Apple's privacy and security mechanisms.
For example, the update on Monday sheds new light on the secure channel between the Magic Keyboard with Touch ID and the Secure Enclave in an M1iMac.
According to Apple, that channel is "established in the factory by using a unique key shared between" the iMac and the keyboard. Apple says it's the same mechanism that's used to create a channel between a Secure Enclave and a built-in fingerprint sensor.