Two-factor authentication: why was I asked for my iPhone passcode after I entered the verification code? I signed into iCloud in my Mac and I was sent a verification code to my iPhone, which I entered in the Mac.  But then I was surprised to be asked for the iPhone passcode.


I then got this dialog box, what protected data would be unavailable?

This situation actually never happened again, but I keep asking myself: in what situation are you required to enter the iPhone passcode?
Apple does not hold encryption keys to certain types of protected data held in iCloud such as passwords, health and home. You need to enter your passcode to allow this new device to decrypt your data.