How is this different than Casascious Coins? Will they get stopped by counterfeting laws as well? They look cool.

Casascious coins had the private key etched in brass. These seem to be able to rotate keys. That way you can be sure the previous owner won't sweep. Similar to opendime in that you have to break it to claim.

iirc, aren't there laws prohibiting the production of something which looks like fiat, but which isnt? Liberty Dollars were shut down for this reason. I thought Casascious was ceased for the same reason. Casascious def wasn't ceased just because it had a static private key.

I'd recommend making these not have a resemblance to domestic or foreign fiat notes.

It is one's duty to violate an unjust law.

Besides, there's an enormous industry of challenge coins and anti-counterfit notes to represent all kinds of things that aren't currency.

Casascious was a long time ago and there's a lot more clarity around BTC now. Currently, no agency recognizes it as a currency.

These notes are akin to a decorative display case for your gold nuggets.

etched in brass

Close. The Casascius coins had a private key underneath a tamper-evident hologram sticker.

This seems more like the OpenDime. Where to redeem it you physically alter it (by cutting the "wire" (trace) so that it then changes state to reveal the private key.

Great find, thanks for the share, we've added it to our list of BTC NFC options

10 sats \ 0 replies \ @invar 7 Jun

offline cash is cool but I think the old tried and tested method is what's going to work but i understand that it is currently regulated out of existence.

Its where its a basic paper note, redeemable for gold bitcoin on demand. You are obviously trusting the issuer in this case but with this trust comes a reduction in cost but also an increase in durability among other things. Not sure NFC tags can last more than a 10 years- But who knows.

Wow, amazed we missed this. Thanks for posting @nullcount.

As a few folks notes, the intention here isn't storing your whole stack in these. They're meant to complement BTC in cold storage. Our primary intent is that they are tools for gifting an education. Onboard a family member quickly with a beautiful piece that they can share. Show one off to a nocoiner and help them understand that Bitcoin is money.

We do not load notes, you do. We store an encrypted private key on each note (we generate the key) and you add a user key in plaintext. From those two you send the funds to a multisig generated in our app. We release the decryption key when you cut the note (we can authenticate that via the app). If we die or censor, the multisig downgrades to just the user key after Jan 3 2029. You can re-key notes that were loaded by untrusted parties. If you load less than face value, note scans as invalid. If you load more than face value, the remainder is used for fees during load.

The notes contain currency-grade security features in the printing (not that these really matter, it's all about the keys on the NFC chip -- but they look cool) and use a resilient synthetic paper.

Happy to answer any other questions here, or at @offlinecashco.

Very interesting! I might get a few for the novelty. Really nice designs.

Physical notes for just holding doesn't really make sense, because there are better ways for cold storage. The main purpose of a physical note is to enable bitcoin to be used as a medium of exchange. It's easy to exchange with instant finality, it protects privacy, and it works in offline settings.

I skimmed through the patent, but I'm still confused how it works. It is a multi-sig wallet which can be re-keyd with just one key, but can't be spent without cutting it. How does it exactly work?

I'm starting to think the primary use case is to put a bunch of them in a picture frame and hang on your wall.


Its an interesting design. I'm skeptical of course, but still it might be useful for the "something you can hold in your hand" crowd. I might not want to put my main stack into it, but I'd try a spending amounts worth.

I don't think you can send funds to it. They come in predetermined sat denominations.

So, firstly, if you have a public key, you can send funds to it lol

But secondly what I meant was, I wouldn't order so many predetermined sat denominations that it came out to my full stack

Ahh of course. Although, that kinda defeats the purpose of having denominated bills.

This 10mBTC note has a whole coin on it. Yet, "you don't have to be an expert to count your holdings".

Seems like a isomorphic novelty for sure.