But it's still pointless.
NFC concept is OK contactless stock control where a barcode is inconvenient. It's stupidity as part of a secure system.
An NFC Ring does exactly what it says on the tin: it’s a piece of jewellery with two NFC tags embedded in it that pass information to nearby phones, tablets and other gadgets by radio. Given that NFC has been a bit of a flop, this may seem a little pointless. Even the technology flag-wavers have stopped claiming that “next …
I don't think it is completely pointless, but it isn't quite there yet. It needs to be no bigger than a wedding ring, tough, passive (no charging!). But if it was, then I think the unlocking phone/house use case might be useful.
Personally I don't set a PIN code on my personal phone at all -- I have never lost one or had it stolen (and I have had a mobile phone since the analogue days) so I choose convenience over security. I would use security which didn't require me to do anything to use the phone! And a ring is much less likely to be lost than a set of house keys in my pocket.
I am yet to be convinced about the bitcoin wallet use case, though!
Yes those immobiliser RFID chips car manufacturers have been using in ignition keys for the last fifteen years have been an unmitigated security disaster, and the level of credit theft from the millions of oyster cards in use in London's transport system is an absolute scandal!
I looked at NFC advertising for a website I'm promoting. It requires the user to bring their (supported phone with NFC turned on) very close to be prompted to open the link. Not ideal. As far as I'm aware your screen needs to be active or you could walk up to someone and make their phone do stuff without them knowing which would be great wouldn't it?
"until you get locked in/out during a powercut."
For that reason, nobody with any sense installs a domestic front-door locking system that needs a key to open it from the inside — I suspect that doing so may even be a breach of fire regulations.
It's certainly a breach of common sense, particularly for anyone who saw Westworld.