This is cool, I thought of something similar, didnt know someone implemented it and the swizz like bank note design is neat.

but its still has flaws imo and just makes it a novelty rather than something practical or useful, for example unless the vendor has change, you would have to spend your btc cash denomination as a whole or exchange it for fiat. what if both the vendor & customer didn't have internet access, how would they check if the cash hasn't been used? idk if you can write back to an rfid that may solve some problems

Are you involved in the project? I assume this is essentially a paper-thin HSM/Yubikey, right?

Is there any way I can use these as general-purpose HSMs outside of bitcoin/cryptocurrency contexts? Just as a novelty.

Let's say I just want to store a private key on it and use it for SSH/etc authentication - would that be possible?

It's a hardware wallet that just looks cool. Where's the "black mirror vibes". There's not much nefarious tech here.

The ick and black mirror vibes comes from the technical fact that bitcoin is non fungible and publicly traceable by design making it a surveillance states dream.

Luckily there are superior alt coins that don't have that flaw.

Err, actually the ick factor for me was the crypto bro mentality and the general seedy nature of the state of crypto and those who use it.

Turns out if you only look at people trying to turn a profit you will find bad people. It's like complaining about investment being seedy because you only watch wallstreetbets.

That should be the point where the intellectual curious hacker should try to broaden there horizon beyond the superficial surface.

I don't see the seedy nature you try to apply to a whole industry if anything i experience the opposite.

Dosage makes the poison.