This is a very interesting topic and a very vast subject.
These NFC wallets are quite different. I am not sure how they run. There might be several types :
- Some that come with privkeys already in them.
- Some that are blank of data, with a mechanism to generate a privkey.
There is always a possibility for hardware backdoors. (
https://en.wikipedia.org/wiki/Hardware_backdoor)
First thing : The possibility is limited since NFC stands for Near Field Communication, which doesn't allow for use on a wide area. So a massive sweep attack wouldn't work.
Unless the private keys are recorded or generated upon a set of data (seed) belonging to the maker, no massive sweep is possible. (and unless the 5G and 6G networks don't use the same frequencies as the ones used in NFC)
Second : Unless each and every part of what makes the chip (electronic circuitry, micro-controller code, components wiring, etc ...) are open-source, published, and reviewed by peers, why not.
I'd be very weary with any proprietary wallet solution anyway.
Third thing : What is stored on the chip ? Is it the private key in plain text ? If not, then there should be a mechanism to sign transactions with privkey and only transfer the transaction raw hex code to whatever appliance that is communicating with the chip.
And if it is the private key in plain text, it is very vulnerable to exploit. You just need a NFC reader to extract the privkey. (most smartphones are capable of it)
People can charge your card with contactless quite easily. (
https://www.youtube.com/watch?v=EONQdQOzphI)
If the privkey is in plain text on the NFC chip, what prevents someone to make a copy of it ?
I believe there might be an NFC bitcoin wallet someday. There are already Bluetooth ones.
In the end, it is a complicated topic, much more than simply printing the private key. So many solutions are possible, but it should be shaped as an international, standardized, brand new protocol.
When ISO for
BTC wallets ?
