This comes straight from the department of "Silly convergence ideas"....
Suggested by the CTO of a major operator at a conference this morning: Putting the function of physical keys (for actual door locks, not crypto) onto your mobile phone.
Yeah right. So when I divorce my operator (ie churn) do I need to change the locks on my house and car?
And if I accidentally leave my phone in my other jacket & walk out & slam the door.... I haven't got either my keys, nor the phone to call a friend or locksmith. Or if I lose the phone etc etc. Having separate (diverged) phone+keys gives redundancy & backup. Or if I've got 2 or 3 phones.. do I have to remember which one has my house keys in it?
OK, I guess I can see this working for certain cases - perhaps replicating a hotel key-card function on a phone. But even that is fraught with difficulty (roamers and handset diversity, basically)
And yes, there might be a few other niches (locker keys or padlocks, perhaps). But not "mission critical" keys for my front door or car.