Excited to show off something that we've been working on: the Bitcoin Note. The Bitcoin Note is a cash instrument that is backed by Bitcoin via multisig. Each note is printed with beautiful, currency-grade elements that use secure printing techniques typically reserved for government documents like microtext, raised print and foil. More importantly, each note includes a secure NFC chip which is where a multisig lives that allows you to claim the Bitcoin at any time.<p>We were heavily inspired by OG Bitcoin physical money like Casascius coins, however, we wanted to created a design whereby (1) anyone can spend, gift and share the Bitcoin for years to come without having to worry a sophisticated attacker who extracts a private key from under a label or scratch off and (2) trust was minimized on that part of the printer (us).<p>This lead us to the design we landed on for the Bitcoin Note<p>1) An NFC chip readable by nearly all modern smartphones<p>2) A two part multisig where (1) we write an encrypted private key to the note (and don't keep a copy and (2) you write a user key to the note in plaintext and then load the note<p>3) We only release the decryption key when someone cuts the note and reports this via an authenticated and encrypted way to our server<p>4) The multisig reverts to only your key after a printed expiration date on the note<p>5) You can re-key the user key on the note you receive if you want to hold it for a long time<p>We believe that the result of this design achieves the goal of Bitcoin that's incredibly easy to use - like cash - but still preserves the important quality of self-custody. Take a look at <a href="http://bitcoinnote.com/" rel="nofollow">http://bitcoinnote.com/</a> to learn more and reserve a spot in line for our release later this summer.
Am I missing something about how cutting notes works, or am I correct in saying that cutting notes relies on a centralized single-company-controlled server being both online and releasing a decryption key?<p>This entire release seems a little bit light on technical details so it's not clear to me exactly what notes are doing when they're transferred, but it does seem like on first glance there are a lot of red flags here. I would love to see a more detailed technical breakdown on that website that isn't just promotional material.<p>----<p>Even ignoring the centralization angle, all of the verification advice I'm seeing boils down to "scan each note and cut it when you receive it." And if everyone is going to do that, what's the point of using a physical note instead of an app? The promo images and descriptions clearly expect that this is going to be used like cash so that technical burdens are lessened for people who aren't good with more traditional cryptocurrency transaction methods.<p>But if non-technical users use it like cash, they're not going to scan anything. And if you think you can teach them to scan every bill in their wallet with a phone, then... why not just teach them to use the phone?
So, it's paper money, but one that won't survive heat or strong electrical fields, and that you need to use with your phone. And will lose all value if the central repository goes under. And is not recyclable or efficiently burnable.<p>Top work everyone, nailed it.
Hey, this is a beautiful product, and a nice idea. If the value of Bitcoin ever stabilizes, then this could really work.<p>From my perspective as a Bitcoin (and related) skeptic, here's what turns me off, probably an easy fix:<p>> Secure your spot<p>> Reserve your spot in line for one of the first 2100 Bitcoin Note packs shipping this summer. ...<p>...and...<p>> Limited First Edition<p>> The first release of the Bitcoin Note will only be 2100 packs of low serial number notes. ...<p>This turns me off because I hear the same pitch in almost every other ICO-like event: "Get yours now, while it's still juicy and sweet".
Have you done any market fit research before diving into this?<p>Honestly: Spending money like cash and using a secure wallet on my phone is already very very easy. Why would I want to go through these extra steps?<p>If the ONLY answer is "Because it is Bitcoin" then you might have a problem.
Note: I have very little exposure to the crypto ecosystem.<p>I either don't understand the specifics of the keying or it doesn't make sense.<p>There's some kind of private key. Makes sense. But there appears to be some kind of second key. At some point the note will "expire" and only the person who owns the second key can redeem the Bitcoin?<p>If I understand right, either the person who physically holds the note can update the key (in which case what purpose does it serve) or the key needs to be transferred along with physical possession of the note (in which case what purpose does the product serve).<p>Also what does it mean for the note to be "cut"? Like with scissors?<p>Is this product just intended for hardcore crypto folks or is it intended for regular people too?
Doesn't this go against the whole point of bitcoin by relying on a central entity that prints, validates, and transfers the notes?<p>Wondering if this requires a money transfer agent license in the US, since you are holding funds in custody and issuing scrip?
Does anyone remember Bitbills? They did something sorta similar to this very early in the BTC revolution. Instead of all of this advanced multisig tech, instead they put the public key and address in a QR code on the outside and the private key in a QR code held inside the bill. They were likely much more vulnerable to attacks, but they died because they were too early not because of that.
What does the transaction look like on the chain?<p>I feel ridiculous in taking this seriously, but it’s got me curious.<p>One thing that people seem to be missing: you could take the note, pay for something, then that person pays for something else and so on down the line until a person cuts the note to put it in their wallet for online use. That seems to sufficiently anonymize the transactions again, but maybe I’m wrong.<p>I do like the graphic design though.
This feels like a Rick and Morty episode to me. They just reinvented cash money, with extra steps.<p>Only, without the oversight of a central bank.. Without the means to keep the exchange rate in check. They can't change the rate of interest or anything else.<p>So far with crypto the only use cases seems to be criminal. To buy illegal stuff and for ransomware. Maybe it could be useful in countries where the currency is devalued like some in South-America. But then all the extra steps seem to be a big hurdle to me.<p>Someone enlighten me on the merits of this idea.
I was really happy with my Kong cash (earlier project by same creators) and handed it out as gifts. It really does look and feel like money from the future. The wallets associated with my bills becomes unlocked october of this year, but I don't suppose the ERC20 Kong token is worth much atm.<p>I thinking locking up mBTC makes a lot more sense - any reason you went with creating your own token the first time around ? Has BTC caught up with ETH in some matters of programmability ?
I'm going to go full science fiction here: if someone were to let off an EMP (so beloved by 1990s action movies) would any of these notes within range irreversibly lose access to the associated crypto?
I feel like bitcoin isn't energy intensive and environmentally impactful enough for my liking, if only there was a way to add non-recyclable plastic products into the equation too
These bills look really cool, and if the tech is actually decentralized and secure, I could see myself using them.<p>Can you share with us some of the technical details, though?<p>First, exactly what is the mechanism by which the user key is rotated? Does that require a transaction to be added to the blockchain whenever the note is transferred from one owner to another? Does the new key need to be kept on a paper wallet or separate device?<p>Also, when your website says that the decryption key is released when the note is cut—exactly how does that work? Does it require an interaction with your servers? And what is the mechanic by which expiration is enforced?<p>And finally, your say that there is no requirement to trust your company. But you somehow have access to the encryption key yourselves. As far as anyone knows, you also kept a record of the encrypted multisig key before you distributed each note.<p>Why should anyone trust that you are not keeping copies of all the information needed to access the bitcoin stored on the note? Can you step through how exactly you are blocked from accessing the bitcoin yourselves?
The value of this is significant. Great work.<p>If authoritarian governments want to take away cash, this gives an
incentive and mechanism for privately minted cash that will change the
dynamic. I wonder though, how to mitigate against physical forgery. I
get the feeling that this could work out <i>much more</i> trustable than
even the best anti-counterfeit technologies presently used for cash
currency.
Interesting. Years back, I was briefly involved with a somewhat similar project, where coins were used and the second sig was printed under a tamper-evident sticker. That way if the site disappeared there was still a way to retrieve the funds.<p>Can't even remember the name of it to be honest, wonder if it still exists.
This requires too much trust of your service, and I don’t see any significant benefits.<p>If you want to give someone bitcoin, just send some over lightning.<p>No need to add complexity and trust.
This is antithetical to the whole idea of crypto.<p>I have to trust the bill is valid and that the person passing along the bill is honest. There is no central authority who will go after those that make counterfeit bills, like the FBI. There is no central bank that I can go to exchange the bill.<p>Those producing the bills seems like a power grab. If people were to trust in a central authority to produce the bills, then that company has a whole lot of power over a decentralized currency.
How is this better than <a href="https://www.jmbullion.com/1-utah-goldback-gold-note/" rel="nofollow">https://www.jmbullion.com/1-utah-goldback-gold-note/</a>?
These are gorgeous and the idea of physical tokens has a rich history in Bitcoin. Some users love them but others not so much.<p>There are two problems to solve: (1) securing the cryptographic material (aka "private key(s)") stored on the physical token; and (2) securing the cryptographic material not stored on the physical token.<p>I can't speak to (1), but (2) has throughout Bitcoin's history been a very hard problem to solve. Even if the token is the only place that the cryptographic material is stored in all the universe, proving that fact is practically impossible.<p>Unfortunately, the page is light on details and the comments haven't answered al my questions so I'll speculate a bit.<p>It appears that this approach goes in a slightly different direction than others with "multisig." This implies to me that both issuer and user generate private keys. This could be a 1 of 2 (either user OR issuer must sign) or 2 of 2 (both user AND issuer must sign). If 1 of 2, the note issuer can in principle always spend the money at any time. If 2 of 2 the user needs to secure the private keys or risk being locked out forever.<p>Either way, we're right back at the fundamental problem: how to secure those keys. If the funds can be lost through loss of user keys, then this offers little practical advantage over bill-less bitcoin. If the issuer can always sign unilaterally, then users become dependent on a trusted third party, which is exactly the problem Bitcoin was created to solve.
Purely from a notaphilist (had to look that up) perspective, the note designs look really cool, and I think integrating an nfc chip / electronic into currency is a neat innovation.
How easy is it to attack this by cutting the specific part of the note that releases the key but making it look like it's whole? Couldn't I cut the note in half and tape it together again and fool someone who doesn't know much about it? Or couldn't I cut the specific bit with an Xacto knife, take the funds and still circulate the bill?
So I guess you have to...buy the bills? Which seems odd. But if they're not super expensive relative to their denominated value it could make sense. I might pay $1-2 per $20 bill for the novelty factor.<p>This definitely seems more convenient than performing a 10m blockchain transaction. But what's the value prop over USD cash? Just novelty?
Another person saying "trust me with your crypto". People want to make money by putting fences around it. Not really offline or secure if you have to get the decryption key from someone else's servers... Interesting idea, though users need to understand the security tradeoffs they are making by using these.
How can I ensure that the Bitcoin on the note isn't corrupted in some way such that it might not be accepted by certain exchanges - Bitcoin that has been through a tumbler for example. Will your mobile apps by able to perform those kinds of checks for me, or will that require me to take extra steps?
I liked BitBills. They were simple to understand, and I knew the tradeoffs and where I was reliant on trust.<p>I'm technical, but even after reading your website a couple times over I still can't say I understand your Notes. They're gorgeous looking, that's about all I can make out.
Cool idea, and the notes themselves look really nice. How does it work if I were to give someone one of these notes? To 'claim' the BTC (assuming they aren't passing the note around between people indefinitely) do they need the private key from the original owner of the note?
Aside from finding the premise questionable, I do find it incredible how US-centric this is:<p>> Printed on a synthetic paper that can’t easily be ripped or torn like fiat, Bitcoin notes are designed to be durable for years to come.<p>Several countries (Australia, New Zealand, Canada, Vietnam, Papua New Guinean, Vanuatu, and many more -- including the UK just recently) use polymer bank notes and have for decades so it seems like you were beat to the punch by several fiat currencies. Also it seems like the design is based around you tearing off part of the note when it is used, so making it hard to tear seems like a strange design choice.
Wow, this is beautifully done.<p>The site mentions the decryption key is released when the note is "cut". Does that mean there's something enclosed in the bill, and you have to physically cut it open to extract it?
>3) We only release the decryption key when someone cuts the note and reports this via an authenticated and encrypted way to our server<p>How exactly is this step done? How can you securely verify a note is destroyed?
Regarding the multisig: Is it possible for a government to, say, point a gun at your head, and seize the bitcoin, even if the holder of the note remains safely out of their reach?<p>(Either way, thank you for your service!)
While its an interesting project, aren’t we going towards a cashless society? I don’t know how its in the US, but in countries like in Sweden there are almost no places where you can pay with cash.
Very cool! Can you offer "partial notes" where n of m notes can be combined to spend the note? Could be interesting for people who want to leave an inheritance in an untrusted regime.
The world has apparently gone full crazy, as we're now back to where we started, with the (rather big) difference that we've replaced sovereign-backed currencies with ... what exactly?
<p><pre><code> > we write an encrypted private key to the note and don't keep a copy
</code></pre>
If the private key ever existed in your custody, there is no way to prove that it was not copied. Sorry. No amount of "trust us" is good enough here. Hell, you may not even know if it was copied if your process was compromised. The only way for a private key to be private is for it to never leave a secure device that generates it. (And even then, there are numerous caveats)
It's interesting, but it seems like it relies on technology a bit too much to really be a cash equivalent. Particularly the centralized server required.
As I understand, this requires two fold sanctity - one for the printed form and one for the NFC. For being not a counterfeit now two conditions have to be met independently and simultaneously. Has it been considered that while accepting it neither visual verification, nor electronic verification are enough alone given that it is meant to be circulated among strangers in all imaginable and unimaginable circumstances?
This sounds like it incorporates a typical NFC tag (presumably with a hard-to-clone chip) with a packaging seal option like was used for the more ordinary...<p><a href="https://www.nxp.com/company/blog/nfc-gets-cheesy-with-kraft-singles:BL-NFC-GETS-CHEESY-WITH-KRAFT-SINGLES" rel="nofollow">https://www.nxp.com/company/blog/nfc-gets-cheesy-with-kraft-...</a>
Wasn't this already tried in the early days? printcoins.com made paper notes with private on them and a picture of Ron Paul X-D <a href="https://www.buzzfeednews.com/article/katienotopoulos/guess-whose-face-is-on-printed-bitcoin-money" rel="nofollow">https://www.buzzfeednews.com/article/katienotopoulos/guess-w...</a>
What if your server doesn't exist in 5 years.<p>Its not really 'offline.cash' when a user needs to ask permission to your server to access their funds.
This is straight out of a fairy tale. An evil fairy can make money that looks just like real gold (I mean Bitcoin) and even passes the test when a lesser mage waves their wand (I mean smartphone) over it. But then it will evaporate in a while and will have no value at all.<p>I love it!<p>In other words, this whole scheme depends on the NFC chip doing exactly what it claims to.
This is a bit off-topic, but I'm curious about what other think here.<p>I like the aesthetic of US cash. I find it elegant and pleasing. It was better before they made all the heads huge, but I have learned to live with it.<p>I cannot stand the off-sized, party-coloured money in Europe. I don't like how it feels in my hand, and I don't like how it looks, at all.<p>I suspect that I am in a very small minority!
Beautiful design especially the subtle Guilloche, but I personally have doubts this solves a real problem and in fact it seems to go totally against the culture of crypto.<p>As a short-run art piece, it makes sense, but I can't see this being used in the real world. Sadly, it feels to me like this is just another project trying to cash-in on crypto hype.
A few things that I don't understand:<p>1. The private key is itself encrypted and stored on the note. Where is the key encryption key stored? On this company's servers?<p>2. Where is the proof that the note is cut? Are there physical traces embedded in the note? Can someone bend the note over and over again to break the traces?<p>3. What prevents exfiltration of the user key from the note?
I've got only one question. Can this note be verified without ability to being spent? In other words, is there a cryptographic proof of validity, that doesn't give the validator ability to transfer value?
If users rely on your service to redeem and the printing really is secure, why not just print the bill and redeem manually? If you do it for ETH, you could store it staked and profit like Circle or Tether does with dollars, at least until you're in jail. Any russians or iranians want to start a business?
<i>Very</i> interesting idea.<p>I'm still wrapping my head around the multisig use, but there was one confusing point on the site:<p>> <i>The stored Bitcoin is only claimable when the holder cuts the note.</i><p>"Cuts"? Does that word mean "issues" or "spends"?
This is some very fancy printing. How much does one of these cost to make? How much are you going to ask people to pay for them?<p>The smallest denomination is roughly equivalent to US$30 so I don't think this is a thing that falls into "if you have to ask the price, you can't afford it".
> Printed on a synthetic paper that can’t easily be ripped or torn like fiat, Bitcoin notes are designed to be durable for years to come.<p>Is this similar to "plastic" cash like Australian and New Zealand bills? Nearly impossible to tear, don't wear out nearly as fast as US bills.
As an American rooted in the puritanical foundations of my country I do not support speculative financial instruments and believe rather money should come from strong hard work ethics. Therefore I do not approve of these crypto currencies
Cool idea! But how do you make sure that I didn't just pretend to cut the note? If I could fool you into believing I've cut it then I could pay someone with a worthless note.
It seems kind of complicated to me, but i guess its a niche novelty paper wallet (as opposed to using a paper napkin with your seed phrase).<p>having the "cash" part might be a bit confusing too.
This is really cool, the notes have a wonderful design. Now I'm curious if this is possible with Monero.<p>I could definitely see this being used at Bitcoin meetups or other crypto-events
Hopefully works out better than Escobar Cash ECH <a href="https://pabloescobar.com/" rel="nofollow">https://pabloescobar.com/</a>
I originally thought this was a joke… because normal “offline” cash that I can spend… isn’t on the blockchain… wait… LOL.<p>If I claim the bitcoin, I no longer have the paper? And if I have the paper, I don’t have the bitcoin? It’s more like buying a paper bond, with the risk profile flipped upside down?<p>Lols.
Question: how much is it going to cost you to spend your $5 note on chain when you finally want to redeem it as BTC on the network? $1, $2... maybe $50 in 2030. So now it's worth -$25.<p>Just use Bitcoin Cash.
That's just a joke I'm too stupid to get right?<p>You make a physical representation of something digital which also changed denomination quite often the last 10 years?<p>What do I do with it?<p>I mean first of I need to check if the value is on that note so I need a smartphone. Now I have a smartphone why do I need a note?<p>The only useful thing would be if I as the giver don't have a smartphone but than I also need to give away a printed object. How cheap can someone print something like this?<p>Now Bitcoin makes even more garbage?!
Can't tell if this is satire or not. Must be some kind of elaborate joke that I don't quite get. But in case it's serious:<p>> <i>censorship resistant money</i><p>Ordinary cash is very censorship resistant, that's why it's used by so many criminals. Ever watched Narcos?<p>> <i>before you accept one of these things you should validate that it actually contains funds? > Yes; depending on who gives you the note you might trust that they have done this for you</i><p>So... much, much worse than actual cash, to the point of complete absurdity.