Why can't I unlock my computer with my iPhone?

[Rod]

Just an idea here but it seems completely logical to me, but maybe I've overlooked something. I can unlock my Apple Watch by unlocking my iPhone and I can unlock my MBP with my Apple Watch. So, why cant I unlock my MBP with my iPhone?
Obviously it would have to be incorporated into the Security & Privacy settings as is the Apple watch but other than that how difficult could it be? Assuming it would not be too difficult the question here may be why wouldn't they provide this function? Could there be security issues?
What does everybody else think? Is it possible I've actually come up with a great idea?

 

[chscag]

That's probably something Apple will add to the list of new things that you will be able to do with your new ARM (Apple Silicon) computer and iOS. Supposedly you'll even be able to run iOS apps on your new Apple Silicon machine.

After all, you can now unlock your front door with your iPhone and the right hardware installed.

 

[MacInWin]

I suspect that the phone won't turn out to be as handy as you might think. As you said, the  Watch unlocks the Mac by being unlocked itself, which is accomplished by either entering a code on the Watch and then not taking it off, or unlocking it with the iPhone by unlocking the iPhone with the watch on your wrist and then not taking it off. So, by not taking off the watch, it knows YOU are YOU, so as soon as the Mac wakes up, sees the watch and queries if you are you, it can confirm and then unlock the Mac. If you remove the watch from your wrist, even for less than a second, the watch locks and cannot unlock the Mac until you unlock the Watch again. So, with an iPhone and no watch, while it COULD work, it would require that the iPhone know that YOU are YOU at the instant of the request, which would mean that you would have to unlock the Phone and then turn on the Mac, or the Mac would have to wait for the iPhone to wake up if it were off, both of which are no better than just typing in the password on the Mac. Now, if the Mac had facial recognition...

 

[Rod]

Good points Jake. My wife's MBP has Touch ID on the Touch Bar and I was thinking of a similar arrangement with the iPhone. Use my fingerprint to unlock my iPhone which, if in Bluetooth range unlocks my MBP. Thinking through that it seems no more of a security risk than the Apple watch but I suppose it's duplication if you have a watch but could be handy if you don't. Probably missed the bus with that idea. As Charlie said with the new silicon macs we will certainly have Touch ID and maybe facial recognition too.

 

[MacInWin]

There is no reason for a Mac not to have facial recognition. The only challenge is that macOS can have multiple users and multiple accounts, but the iPhone, iPad and  Watch are single user. So facial recognition is easier, only one face to remember. And only one pairing from phone to watch to monitor. But with Apple Silicon, it should be fairly simple to have facial recognition. One issue might be, though, what to do if USER A is logged in, moves away from the machine and USER B shows up? Log A out and B in? Switch from A to B? Ask for what to do? All do-able, maybe even configurable by machine, but things that make it more complex.