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Show HN: The Bitcoin Note – Secure, Self-Custodial Bitcoin Wallets in Cash Form

• _robbywashere 4y ago
  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
  • kadoban 4y ago
    I can't tell if this is satire. If it is it's pretty good. If not, no offense meant. The "puritanical" foundations of the US had _tons_ of speculative financial instruments, including the colony/state/US currencies in their early years/decades.
• ccamrobertson 4y ago
  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. 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). This lead us to the design we landed on for the Bitcoin Note 1) An NFC chip readable by nearly all modern smartphones 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 3) We only release the decryption key when someone cuts the note and reports this via an authenticated and encrypted way to our server 4) The multisig reverts to only your key after a printed expiration date on the note 5) You can re-key the user key on the note you receive if you want to hold it for a long time 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 http://bitcoinnote.com/ http://bitcoinnote.com/ to learn more and reserve a spot in line for our release later this summer.
• superb-owl 4y ago
  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. This definitely seems more convenient than performing a 10m blockchain transaction. But what's the value prop over USD cash? Just novelty?
  • paulgerhardt 4y ago
    One of the co-creators here. The toy version of this is like buying a hardware wallet with the Bitcoin in escrow. The eventual flow is more like an ATM. There one kind of already "buys" cash in the form of a service charge (often refunded by one's own bank). Cash is the most common form of peer to peer payment. Bitcoin is the best form of peer to peer money. This combines the two. It allows for instant, anonymous settlement in regions with poor connectivity (El Salvador, Ukraine.) Lower barrier to entry for very old and very young users. Skips the complicated process of onboarding people into learning about key management - everyone already knows how to keep cash secure. Getting self-custody of Bitcoin is important but usability has always been a challenge. This attempts to solve for some of those problems, particularly in cash economies where Bitcoin adoption as a medium exchange is more popular. Basically let's get everybody using self-custodial, multi-sig hardware wallets with really, really good privacy properties but make them not intimidating by presenting them in a skeuomorphic cash form.
    • ntoskrnl 4y ago
      I love the idea behind this! Having said that, it will take a lot to convince experienced users to trust these over on-chain transactions. The info on your website is pretty sparse - there's not nearly enough info there to work out the security properties of these notes. I'm piecing together how it works from your various comments here, but you really want to have all that info in one place. I'm sure you know this already and I'm sure you're working on the website behind the scenes, and I look forward to reading when it's done! What's your business model? Do you plan to recoup costs by selling the physical notes, or is there some other plan?
    • yunohn 4y ago
• thebeastie 4y ago
  So, I assume before you accept one of these things you should validate that it actually contains funds somehow ?
  • ccamrobertson 4y ago
    Yes; depending on who gives you the note you might trust that they have done this for you. We will have iOS and Android apps available (and we will open source them for peer review as well).
    • simonw 4y ago
      "depending on who gives you the note you might trust that they have done this for you" There is absolutely no way I would trust that - because even if I trusted that person's integrity I would also need to trust that they themselves had the technical knowledge to reliably make that confirmation. And that they hadn't made a mistake.
      • ccamrobertson 4y ago
        There is one case, which I believe is a common one where I would argue this might not be true -- a crypto savvy family member is the first person to purchase and load the notes before gifting them to you. But, fair point. I would always err on the side of recommending someone scan a note rather than not.
        • simonw 4y ago
          Agreed, that's one case where I could see myself trusting someone here.
• mmastrac 4y ago
  What happens if this service goes away? Are the bills worthless?
  • ccamrobertson 4y ago
    No; this is a fantastic question and why the notes consist of a multisig with a timelock. After the timelock expires only the user key on the note can retrieve the funds. So in the worst case scenario where we go away or refuse to validate notes day 1, you will be able to retrieve the funds after expiration (Jan 3 2029).
• cortesoft 4y ago
  How can you know that someone hasn't transferred the bitcoin out of the wallet before they give it to you?
  • Vladimof 4y ago
    > How can you know that someone hasn't transferred the bitcoin out of the wallet before they give it to you? How can you know someone hasn't transferred the money out of their bank account when they hand you a check?
    • UncleMeat 4y ago
      A very large number of organizations won't accept checks from random people precisely because of this problem.
      • Vladimof 4y ago
        Do you have any examples? I don't really use check nowadays...
        • cortesoft 4y ago
          At this point it would be a better question to ask who DOES accept checks. In the US, most grocery stores still accept them, but I don't know of any other stores that do.
        • _fizz_buzz_ 4y ago
          In Germany I have a hard time of thinking of a place that does accept checks as payment. I did get a check a couple years ago from an insurance company that reimbursed me. But besides that I haven't ever used a check in Germany.
      • jacobsenscott 4y ago
        Can't you instantly run the check electronically since the routing/account numbers are right there. I suppose you would need to pay for a POS terminal that does that, which might not be worth it.
• Fargoan 4y ago
  So it's like Open Dime but with printed bills instead of a USB stick?
  • ccamrobertson 4y ago
    Yeah -- similar. Open Dime is focused on securing a single key until it's tampered with; we use a multisig with timelock instead for a couple reasons; (1) the chips we use are simpler and entirely powered via NFC (2) our notes are intended for broad circulation over a long period of time.
    • Fargoan 4y ago
      Very cool. I'm on the reserve list. How much will you charge per pack?
      • ccamrobertson 4y ago
        We don't have pricing ready just yet -- roughly in the Opendime territory.
• skeeter2020 4y ago
  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?
  • programmarchy 4y ago
    ...something other than a military, which is a step forward.
    • notahacker 4y ago
      Except of course, that most central banks function perfectly adequately despite the nation in question having very limited military power, and it isn't as if Bitcoin mining operations don't depend on there being enough use of force behind the rule of law for property to still be enforceable.
  • throwaway4aday 4y ago
    I don't think it's irrational to disagree with your personal beliefs about monetary systems. There's evidence both for modern practices being beneficial as well as detrimental so I'd reserve judgement until it plays out. Besides that, what's wrong with a private entity issuing its own scrip? It's how our current system of currency got its start with private banks issuing promissory notes which were eventually adopted by the state. You probably personally hold quite a lot of it in the form of debt or reward programs. This goes a little further in that it is redeemable for an alternate form of currency not backed by a state but that's not really an argument against it, historically people have used all kinds of alternate currencies. It really just comes down to what two individuals agree is an appropriate medium of exchange whether it's bitcoin, dollars or cigarettes.
    • Agamus 4y ago
      "Besides that, what's wrong with..." Nothing 'wrong' with it, per se. But the whole concept reads like a bad Saturday Night Live skit.
  • 4y ago
• andrewmutz 4y ago
  I'm not a fan of anything crypto, but I have to give you credit on this: the visual design of the currency really is gorgeous.
  • Kaze404 4y ago
    They look too similar to the Real bills in my opinion
    • spicybright 4y ago
      Frankly it seems like the best use is putting them in a display case as a curiosity.
  • ccamrobertson 4y ago
    Thanks for the kind words -- it was incredibly fun to go through the design process of something like cash since we're all intimately familiar with the end product. It was a pleasure to work with an actual banknote designer, Tom Badley, to accomplish this.
  • kens 4y ago
    I like the "portrait" layout of the currency, compared to "landscape" for regular currency.¹ It makes it clear that there's something unusual about this money, a feature that I'd always taken for granted but suddenly is different. ¹Does anyone know of a country use portrait layout?
    • timbit42 4y ago
      Canada's 10 dollar bill does https://www.blogto.com/city/2018/11/10-dollar-bill-canada/ https://www.blogto.com/city/2018/11/10-dollar-bill-canada/
    • przemub 4y ago
      That would be Switzerland! https://en.wikipedia.org/wiki/Banknotes_of_the_Swiss_franc https://en.wikipedia.org/wiki/Banknotes_of_the_Swiss_franc
• sschueller 4y ago
  So you hold the keys until they expire? What happens when your key expires if the user has added funds and does not re-key the note before that time?
  • deleted 4y ago
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  • ccamrobertson 4y ago
    We don't hold any Bitcoin key material; all of it lives on the note. One of the keys you contribute, the other one is encrypted by a key that we store (and release when the note is cut). If the note expires then only the user key on the note can claim. However, this is an important risk to consider -- if you have notes on hand that have expired and you haven't re-keyed them, there will likely be a race at expiration to claim for anyone has encountered the note. We recommend that if you don't plan on spending a note right away (as cash) that you re-key first to ensure that you're the only one who can claim at the point of expiration.
    • natch 4y ago
      You don't explain anywhere what you mean by "cut." And what is a "sewer" in your world? (Edit: I think it's a typo for "server.")
    • ryukafalz 4y ago
      What does that re-keying process do exactly? Surely it’s not just updating the key on the device itself, because then it wouldn’t do anything to stop people claiming encountered notes at the point of expiration, if I’m understanding this correctly. But it can’t be moving the funds to a new wallet either, because you don’t have control of the second private key yet. So… what exactly happens there?
• captn3m0 4y ago
  Doesn't this go against the whole point of bitcoin by relying on a central entity that prints, validates, and transfers the notes? Wondering if this requires a money transfer agent license in the US, since you are holding funds in custody and issuing scrip?
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  • ccamrobertson 4y ago
    The construction of the multisig is such that (1) the key we generate and store encrypted on the note can never access the funds alone -- and we don't store it because we don't want to be custodians and (2) the end users load the notes, we never touch BTC.
    • ALittleLight 4y ago
      I think you need a better explanation of the multisig procedure and how you are not a central authority, capable of spending the bitcoin, etc. I've seen multiple comments here confused by this.
      • ccamrobertson 4y ago
        Thanks for the feedback -- agreed, that's definitely become apparent.
        • quickthrower2 4y ago
          Yes, people need to know: 1. What are the steps to purchase it. 2. What are the steps to spend it. 3. What are the steps to receive it, including verification. 4. Convince me I won't lose my funds by accident. 5. Convince me I won't lose my funds by hack of protocol. 6. Convince me I won't lose funds if a hacker gains access to your centralized system. 7. What happens if I lose the note(s)? 8. Processing fees. 9. Can I give someone a note and avoid the Bitcoin transaction fee? (I am guessing yes as nothing needs to happen on the chain. But if I receive a note can I be sure I won't be swindled).
• basisword 4y ago
  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?
  • ccamrobertson 4y ago
    All key material for the note must be written to the note so that it is fully bearer (otherwise it's invalid and our app will reflect as such). So, just like cash you can hand the note to someone and using the app they (1) can tap the note to see the public keys and verify it is loaded and (2) cut the note to claim (the fact that the note is cut is sent to us at which point we respond with a decryption key to unlock the second private key that lives on the note).
    • deleted 4y ago
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• simonw 4y ago
  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?
  • bsedlm 4y ago
    so you want bitcoin as non-fungible cash? isn't that a counter to the whole point of a cash-currency?
    • simonw 4y ago
      Yeah, I do find the fact that Bitcoins are not in fact fungible darkly amusing.
  • ccamrobertson 4y ago
    We have no checks in place like this today, but that's an interesting suggestion. Sounds like some sort of OFAC address checker?
    • simonw 4y ago
      I wonder if anyone's built an API that handles this kind of thing yet - seems like the sort of thing a company similar to Infura would offer.
      • captn3m0 4y ago
        Found one: https://docs.sanctions.trmlabs.com/#section/Introduction https://docs.sanctions.trmlabs.com/#section/Introduction
• programmarchy 4y ago
  Wow, this is beautifully done. 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?
  • throwaway4aday 4y ago
    I'm guessing it means you need to destroy the note in order to redeem it which makes sense as a way of remotely "redeeming" the note with the issuer. I'm interested in how secure this process is since the entire system would hinge on it.
  • ccamrobertson 4y ago
    Thank you -- then chip has a tamper trace that needs to be cut (you cut roughly 1/4 of the note to slice it). Once the trace is cut the app can report that fact to us at which point we release the decryption key.
• nickphx 4y ago
  why though?
• deedree 4y ago
  This feels like a Rick and Morty episode to me. They just reinvented cash money, with extra steps. 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. 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. Someone enlighten me on the merits of this idea.
  • calvinmorrison 4y ago
    I guess, you can easily confirm if it's counterfit
  • capableweb 4y ago
    > 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. You seem to have nailed the use case well. This is exactly why'd someone use something like this. I'm not saying it's a good idea (nor a bad one), just that those things are "features" in the eyes of the cryptocurrency users and proponents, not bugs.
    • metalliqaz 4y ago
      "for the crypto enthusiasts, the problem with the legacy financial markets wasn't that they were manipulated, it's that they weren't in on it." (reproduced here from memory)
      • sunshinerag 4y ago
        “For the fiat incumbents, the problem with crypto markets is it pulls capital away from their entrenched fiat scams”
        • rchaud 4y ago
          Brian Armstrong didn't buy his $133m compound with BTC, it was from the filthy, debased USD that he exchanged his Coinbase shares for. Everyone's a fiat incumbent in the long run.
• Youden 4y ago
  Note: I have very little exposure to the crypto ecosystem. I either don't understand the specifics of the keying or it doesn't make sense. 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? 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). Also what does it mean for the note to be "cut"? Like with scissors? Is this product just intended for hardcore crypto folks or is it intended for regular people too?
  • ccamrobertson 4y ago
    > Also what does it mean for the note to be "cut"? Like with scissors? Yes, exactly. There is a spot indicated on the note to cut it. This "tampers" the associated chip which can be reported back to us so that we release the encryption key to decrypt the local key. > Is this product just intended for hardcore crypto folks or is it intended for regular people too? Regular people too! The UX of our app will simplify a big part of this by indicating to folks the state of a note and their options with respect to claiming Bitcoin.
    • meltedcapacitor 4y ago
      Can one "glue it back" after "cutting" it, sell it to a mug, and double spend it before they notice?
      • ccamrobertson 4y ago
        Once the tamper circuit it tripped you cannot reverse it. But sure, one could try to carefully do this and pass off a note to someone who doesn't verify it electronically.
    • kadoban 4y ago
      There's no possibility for the end-user to read it themselves from the cut chip? That would be a deal-breaker for me.
• yieldcrv 4y ago
  does this use taproot and schnorr signature style? I like the concept of multisig being indistuingishable from single sig or other scripts.
• jacobmarble 4y ago
  Hey, this is a beautiful product, and a nice idea. If the value of Bitcoin ever stabilizes, then this could really work. From my perspective as a Bitcoin (and related) skeptic, here's what turns me off, probably an easy fix: > Secure your spot > Reserve your spot in line for one of the first 2100 Bitcoin Note packs shipping this summer. ... ...and... > Limited First Edition > The first release of the Bitcoin Note will only be 2100 packs of low serial number notes. ... 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".
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  • ccamrobertson 4y ago
    Thanks for the feedback. Ideally we would have opened up sales right away rather than a waiting list (we have the notes manufactured), but we are waiting to wrap up a few key pieces like the mobile apps. We highlight the low serial notes as we know numismatists like to collect this sort of thing.
    • conductr 4y ago
      > we are waiting to wrap up a few key pieces like the mobile apps Interesting approach but this Show HN got some decent attention. Are mobile apps even necessary? Doesn't waiting for them blow the attention you're getting via HN today?
      • ccamrobertson 4y ago
        We're going to showcase the physical notes in person at Consensus, which is arguably the last major Bitcoin conference of the year (certainly for US market). We've found that having notes in person helps folks to understand the concept more easily.
  • yieldcrv 4y ago
    The bitcoin collector community loves the low number stuff Its a small community but they’ve been around since the Casascius days, long predating crypto asset securities (which predates the ICO)
• simonw 4y ago
  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?
  • ccamrobertson 4y ago
    Yes, probably. I would also recommend carrying the notes in an EMF protected wallet. We have considered a feature which explicitly lets you back up the user keys from notes so that you have this as a fallback claim, but this might also encourage people to just "mine" notes in the hope that someone doesn't re-key. Given there is nothing we can do to prevent this...we might build it.
• stavros 4y ago
  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?
  • simonw 4y ago
    My guess is that this is why the verification mobile app that scans the NFC code is going to be critically important.
    • stavros 4y ago
      But then that kind of invalidates the "offline" claim, I don't think they'd make it if they needed the app? Then again, maybe you need the app but it doesn't need network access.
  • Imnimo 4y ago
    I'm also unclear whether being cut is truly the only way to trigger the release. Could the note be damaged in other ways to get it to think it's been cut? The website is extremely light on details.
• nonrandomstring 4y ago
  The value of this is significant. Great work. 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 much more trustable than even the best anti-counterfeit technologies presently used for cash currency.
  • ccamrobertson 4y ago
    Thank you -- as another commenter noted we cannot act as the Secret Service to remove counterfeit notes from circulation, so the implication probably is that folks need to get into the habit of scanning notes prior to acceptance.
  • arlort 4y ago
    > If authoritarian governments want to take away cash If an authoritarian government is taking away cash they've already passed the step at which making/importing this kind of object is illegal And if you can import this kind of privately minted note then you can also import foreign cash whose value people can trust without having to destroy it and for which they don't have to remember a password (for each note I imagine, it's not clear from the website how any part of it works) There are use cases for these kind of tokens but I can't find one which is efficiently solving a problem not uniquely tailored to rich free countries Just in case, by tokens I am (in this comment) just referring to the notes, not the concept of bitcoin in general
  • rchaud 4y ago
    The private sector has done orders of magnitude more to make societies cashless than any government ever could.
  • alasdair_ 4y ago
    An authoritarian government can just seize the centralized servers that are needed to run this whole system.
  • Termitiono 4y ago
    Either you can use the internet than you don't need that note. You need internet to actually verify and take ownership of the value of it. It only helps if the giver doesn't have internet. And sure it's easier to smuggle this one note over a border than a suitcase bout you could smuggle actually anything with an offline wallet in it like USB stick, CD etc. Why is this significant in your eyes? I'm lost
• jacobmarble 4y ago
  > 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. 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.
  • MengerSponge 4y ago
    It sounds like an innovative way to add a different type of pollution (microplastics) to a bitcoin transaction. US bills are a cotton/linen blend, and the larger denominations don't age nearly as quickly. We should embrace $1 coins, but we won't.
    • paulgerhardt 4y ago
      Having gone to the currency printing industry events the environmental impact of polyethylene currencies appears to be lower and the plastic currencies appear to last longer.
      • MengerSponge 4y ago
        Interesting. I'm kind of skeptical of claims made at industry events, though. Did they also talk about the recyclability of their plastics?
        • paulgerhardt 4y ago
          Not as much, but the most common modern currency substrate is PET which is probably the most recyclable plastic. There are a lot of 'wtf' moments when one gets a glimpse behind the veil of an otherwise super secretive industry but this part at least is actually surprisingly mundane.
• jacobmarble 4y ago
  How did you choose the people portrayed on the notes? Also, who are they?
  • MengerSponge 4y ago
    Pablo Escobar, Johan van Oldenbarnevelt, Francis Drake, and the Koch Brothers? Celebrating drug runners, malicious state actors and pirates, and environmental disaster.
  • ccamrobertson 4y ago
    We used Greco-Roman god statues -- Apollo, Venus, Minerva and Neptune (some of the model statues were Greek, others Roman). We decided that because of the anonymity of Bitcoin it didn't feel right to 'select' portraits of real people representative of Bitcoin, but rather choose aspirational portraits of mythical figures.
• asciimov 4y ago
  This is antithetical to the whole idea of crypto. 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. 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.
  • Vladimof 4y ago
    > There is no central authority who will go after those that make counterfeit bills, like the FBI. Why? They go after people copying bits after all... i.e.: movies
  • ccamrobertson 4y ago
    If you don't trust the bill, scan it to validate the multisig, re-key the note or cut the note to claim the Bitcoin. If you can't validate the note, don't accept it. We don't store key material. We have 0 capability to spend any Bitcoin from the notes.
    • beambot 4y ago
      > We don't store key material. There's the centralized trust... How can you prove this?
      • ccamrobertson 4y ago
        We can't prove a negative, but we can prove that we can't spend the Bitcoin based on the construction of the multisig which the user sends funds to. I primarily state that from the regulatory perspective; we explicitly don't want to be a custodian.
  • seibelj 4y ago
    I don't think you read the website. You can verify the funds aren't spent via NFC chip and the blockchain itself. You then rotate the user key so only you can spend it after receiving the bill. A bit cumbersome but your criticism about trust is incorrect.
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• bambax 4y ago
  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: > censorship resistant money Ordinary cash is very censorship resistant, that's why it's used by so many criminals. Ever watched Narcos? > 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 So... much, much worse than actual cash, to the point of complete absurdity.
  • staticman2 4y ago
    I like it in a cyberpunk dystopia sort of way.
    • Agamus 4y ago
      I used to love the cyberpunk distopia aesthetic, back in the 90s. Now I want less of all of the things in this article. Less digital money, less cellular telephones, less of all of it. By comparison, if it was depressing to see awesome or inspiring technologies get steamrolled and monetized by the MBAs in the early 2000s, this farce evokes despair.
  • thiht 4y ago
    > Can't tell if this is satire or not Me neither, I’m genuinely confused
  • Hyolobrika 4y ago
    > > before you accept one of these things you should validate that it actually contains funds? Where did you read that? I can't find it on the website.
    • bambax 4y ago
      It's a comment here, and the response to it by one of the makers of this thing. https://news.ycombinator.com/item?id=31656090 https://news.ycombinator.com/item?id=31656090
• amluto 4y ago
  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. I love it! In other words, this whole scheme depends on the NFC chip doing exactly what it claims to.
  • ccamrobertson 4y ago
    Presuming you can read the user private key off the NFC chip at least once then you hold Bitcoin after the expiration of the note. No fairy tale, just math.
    • amluto 4y ago
      You need to cut the wires to do this, as I understand it. But, more relevantly, this only applies to the person who made the note. If you want to buy something with this fairly gold note, the recipient has no way to verify that it’s real unless they either trust the manufacturer or they cut the wires and transfer the Bitcoin, at which point one wonders what the point of the physical note is.
      • ccamrobertson 4y ago
        No, after expiration of the note the wire does not need to claim funds from the note. Only the user key is required. If we as the manufacturer are perfectly untrustworthy, this is the final "backup" state. If we the manufacturer are partially trustworthy at any point in time, you can re-key the note then. In no case can we claim funds from the note ourselves.
  • throwaway4aday 4y ago
    > But then it will evaporate in a while and will have no value at all. This is true of the US dollar as well if you look at a 100 year time span.
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• rizoma_dev 4y ago
  This reads like a parody
• tibanne 4y ago
  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. Just use Bitcoin Cash.
  • paulgerhardt 4y ago
    Then treat this like a hardware wallet. It's really hard to make trustless, decentralized physical cash which is what this is. If cryptocurrency is to compete with fiat currency it should be able to do so through all the same mediums fiat can. You can hack these to load them with Bitcoin Cash and make a "Bitcoin Cash Cash" instrument. Previously one couldn't do this, now one can. Comments like this one are why this hardware technology matters: https://news.ycombinator.com/item?id=31656602 https://news.ycombinator.com/item?id=31656602
• jacquesm 4y ago
  What happens to the notes if the issuer goes out of business? Do they lose their ability to be reclaimed?
  • paulgerhardt 4y ago
    Functionally this like a hardware wallet. The tech keeps working long after the manufacturer disappears. The private key associated with the note is loaded on there by the end user and can be rotated by the next person to receive the note. The issuer has no ability to claim the funds on the note. The person holding the note can always claim the funds on the note.
    • jacquesm 4y ago
      Ok, and how do I tell a reclaimed note from one that is still valid when someone hands me a note?
      • paulgerhardt 4y ago
        Each note can be scanned with one's smartphone to check value and authenticity. We're positing the level of scrutiny matches our experience with fiat cash. I.e. I'm very cavalier with checking the authenticity of low denomination notes when getting change at the pool for an ice cream cone and fairly rigorous when selling my hi-fi system to a stranger on classifieds - perhaps even taking time to do the "highlighter test". Counter-party matters too - It may take some time before we can spend these at Bitcoin Beach in El Salvador but they have currency (in the literal sense) with family and friends. These notes have the same security features as traditional currency (UV watermarks, microtext, etc) but also have the embedded chip which is the real thing that matters. I don't think it's perfect but I do prefer it to regular cash which doesn't let me electronically validate it.
        • jacquesm 4y ago
          Ok, so you need a smartphone to be able to exchange the notes. That already makes it a non-starter for lots of people because not only do they now need something resembling cash, they also need a phone. Anyway, interesting project, curious to see where it leads.
• Aaronstotle 4y ago
  This is really cool, the notes have a wonderful design. Now I'm curious if this is possible with Monero. I could definitely see this being used at Bitcoin meetups or other crypto-events
  • ccamrobertson 4y ago
    Thank you; I don't know too much about Monero -- while I see that it does have multisigs, I can't tell if they can change over time. This is pretty important to ensure that we as the note issuer can never block someone from ultimately claiming the funds off of the note.
• jdhn 4y ago
  Like another user said, I really like the design. Are there any plans for larger denomination notes?
• padjo 4y ago
  I don’t understand the significance of the security printing etc. doesn’t this all boil down to the data on the NFC chip?
  • ccamrobertson 4y ago
    Yes -- that's correct. The security printing is really to highlight that these feel and look like real money which we believe is critically important. There is significant literature on the psychology of money and we believe that it has been a big missing piece for the adoption of Bitcoin. Had we just used a color laser printer and attached chips to standard paper the security of the Bitcoin stored would be the same, but the experience for someone holding it would be vastly different. Our goal is that you can gift one of these notes to a family member and they will keep it safe even if they don't fully understand it (unlike a printed QR code or ambiguous gift card).
• hda2 4y ago
  Very nice! How much are the notes expected to cost?
  • ccamrobertson 4y ago
    We don't have pricing ready just yet -- think something in the range of an Opendime.
• wvlia5 4y ago
  can some zk proof be printed visibly in the bill to prove that it contains the given amount of btc ?
  • dropnerd 4y ago
    this seems like an awesome addition. if short enough, it can be placed where the serial usually goes
• danShumway 4y ago
  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? 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. ---- 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. 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?
  • ccamrobertson 4y ago
    > 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? That's correct. > 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. Not quite; rather than cutting the note you could re-key it and store it. Or, if you are planning to use the note immediately or near term in commerce, you might have sufficient confidence that our re-key service won't shut down (but yes, this obviously implies some trust if you hold notes without re-keying of claiming). > 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? Because with a phone alone they need to store their keys locally. With re-keyed notes (or notes from family members who have re-keyed them), they can immediately store notes in a safe place without the problem of phone hacks or loss.
• Agamus 4y ago
  This is a bit off-topic, but I'm curious about what other think here. 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. 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. I suspect that I am in a very small minority!
  • wedn3sday 4y ago
    Personally, I love that euro notes aren't all the same size. It makes it a heck of a lot easier to tell apart notes of different denominations, especially for people with visual impairment. Imaging for a second how you would count money USD with your eyes closed.
    • Agamus 4y ago
      I haven't needed to count cash with my eyes closed yet, with several decades behind me. Aside from how awesome it must be for people with visual impairment, I can't think of how else it is beneficial (though that is definitely enough of a good reason). Are there other benefits? I suspect it's an effect of OCD, but when I have a mess of different sized bills in bright multi-color... my mind is just not at ease.
    • ccamrobertson 4y ago
      We did debate this, but decided to stick with same size notes for a couple reasons -- (1) they're easier to produce in low volume and (2) there is a bit of sensation from the raised print on the large "1", "2", "5" and "10" numbers.
• 5350-uiop-1130 4y ago
  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). having the "cash" part might be a bit confusing too.
• jpmattia 4y ago
  Very interesting idea. I'm still wrapping my head around the multisig use, but there was one confusing point on the site: > The stored Bitcoin is only claimable when the holder cuts the note. "Cuts"? Does that word mean "issues" or "spends"?
  • ccamrobertson 4y ago
    Oh, we need to show a better photo of this but there is a point on the note where the claimer needs to physically cut the note which trips a tamper sensor in the chip.
    • jpmattia 4y ago
      Aha. I was reading too fast (plus I deal with a lot of people who "cut a check", which means "issue a check" in accounting-speak.)
• danschumann 4y ago
  Those printed things are probably still cheaper than the transfer fees are in bitcoin, or did they did those?
• legutierr 4y ago
  These bills look really cool, and if the tech is actually decentralized and secure, I could see myself using them. Can you share with us some of the technical details, though? 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? 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? 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. 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?
  • ccamrobertson 4y ago
    Great questions -- > 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? Yes, for re-keying you need to carry out an on-chain action. The new key is stored on the note. I could imagine scenarios where people don't re-key a note every time, e.g. they expect to spend it in a short time period. > 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? Exactly, our servers are required here. The expiration is baked into the multisig on Bitcoin. > 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. > 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? This is good to highlight -- we could be lying and we could keep the encrypted private keys (again, for a clear statement here regarding custodianship: we don't). But in the case of the multisig the encrypted key only ever allows for access to the funds in conjunction with the user key. There is no scenario where it can claim funds alone.
• jazzyjackson 4y ago
  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. 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 ?
  • ccamrobertson 4y ago
    Thank you, the Kong Cash notes were a labor of love and are now very limited in availability -- glad you got some! With Kong we wanted to create a completely new cryptocash from the ground up with Kong with the idea "what if a cryptocurrency started physical first". It was really a demonstration of the usefulness of secure element chips that generate their own keys -- work we've continued with Kong Land. Unfortunately the chips we use for Kong Cash rely on the P256 curve rather than secp256k1. With Ethereum and the EVM we could bridge this via smart contract, however, Bitcoin script is too limited to achieve the same result (imo with good reason). We landed on a very different chip configuration for Bitcoin which has the tradeoff of some centralized elements, but also allows the user to introduce their own entropy (unlike the chip we used in Kong Cash which in theory has very good entropy, but still relies on claims from the manufacturer). The timelock concept from Kong, however, works incredibly well for the Bitcoin Note as a failsafe for conditions where we disappear or refuse to service notes.
  • ksec 4y ago
    I was thinking isn't it exactly the same as kong and yet there are no other mention of it other than this reply. I wonder if they have an office in Hong Kong or something.
    • jazzyjackson 4y ago
      IIRC they were based in Shenzhen (across the bay from HK), I only knew of the connection because I am on Kong Cash's mailing list.
• rchaud 4y ago
  I feel like I just saw the CS-pandering version of those late night ads for "collectible gold coins".
• stalinford 4y ago
  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? (Either way, thank you for your service!)
  • ccamrobertson 4y ago
    No, this is a super important question to us as we don't want to hold Bitcoin key material. The encrypted key on the note can only be used in conjunction with the user key on the note. If we go away or our servers are seized, then in 2029 the user key on the note can access the funds without needing to decrypt the second key on the note.
• cyphertruck 4y ago
  This requires too much trust of your service, and I don’t see any significant benefits. If you want to give someone bitcoin, just send some over lightning. No need to add complexity and trust.
  • pluc 4y ago
    but then how do I get rich?
    • highwaylights 4y ago
      Be the receiver.
• mgraczyk 4y ago
  If you made one with USDC I would probably buy some as gifts
• jbaczuk 4y ago
  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.
  • ccamrobertson 4y ago
    There are a number of circumstances where the notes can live "offline" without further contact with us -- the primary one we think of is gifting to non-crypto savvy family. Our denominations are also meant to imply this -- we aren't making 1 BTC notes on purpose. The goal is to provide another tool for onboarding and holding crypto.
    • jbaczuk 4y ago
      How does gifting to non-crypto savvy family change whether the note works offline or not? Because they don't understand it so they don't verify that it wasn't spent? Sorry I don't follow, and I'm not just trying to crap on the idea.
      • ccamrobertson 4y ago
        In that circumstance they don't need to be online. The recipient can scan the note entirely offline, get the private key, create a transaction and broadcast it to the Bitcoin network when they are online.
        • jbaczuk 4y ago
          Ah, so they just assume it wasn't spent already because it was a gift. Yeah might make a fun gift.
• kerblang 4y ago
  Is that a goddess in an astronaut suit? :/
• BLanen 4y ago
  This is just centralized, as every solution to a decentralization problem. Defeats the purpose.
  • rchaud 4y ago
    > centralized That's where the money is.
• beders 4y ago
  Have you done any market fit research before diving into this? 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? If the ONLY answer is "Because it is Bitcoin" then you might have a problem.
  • RickTM 4y ago
    Theres also laws against minting private currency, as seen here: https://web.archive.org/web/20121205094219/http://www.fbi.gov/charlotte/press-releases/2011/defendant-convicted-of-minting-his-own-currency https://web.archive.org/web/20121205094219/http://www.fbi.go...
    • quickthrower2 4y ago
      Three reasons why this is probably irrelevant. 1. > Von NotHaus designed the Liberty Dollar currency in 1998 and the Liberty coins were marked with the dollar sign ($); the words dollar, USA, Liberty, Trust in God (instead of In God We Trust) So that is not a great example, as it is currency designed to confuse people into thinking they are real dollars. 2. The USA is just one set of laws. Over the pond in the UK, it is fine. https://en.wikipedia.org/wiki/List_of_community_currencies_in_the_United_Kingdom https://en.wikipedia.org/wiki/List_of_community_currencies_i... 3. This isn't a new currency, it is a new key storage format for Bitcoin.
      • nybble41 4y ago
        > as it is currency designed to confuse people into thinking they are real dollars That was the government's argument. The defendant clearly disagreed. Arguably they were closer to "real dollars" (defined by the Coinage Act of 1792 to consist of 416 grains, or about 0.95 ounces, of standard silver) than anything the government has minted recently. A bit better, even. The dollar sign and the word "dollar" are not unique to US currency and in fact predate the US entirely. Likewise for the word "liberty" or the phrase "trust in God"—if anything that last would probably be deemed a blatant violation of the separation of Church and State if the government actually put it on their currency. These are just generic elements common to many currencies and US culture. Even the initials "USA" don't actually imply any endorsement by the US government; you can find them on just about everything these days. The intent was patriotism, not confusion. The same would have been true if they had spelled out "United States of America" like the official coins, though of course they didn't do that. Any actual confusion can more readily be blamed on the US Mint for making their coins too generic than on NORFED for making theirs too similar. At least NORFED put their name in their design; the US Mint did not.
• mettamage 4y ago
  I don't fully get it. Is it possible again to "void" the note and make the BTC purely digital again?
• s-xyz 4y ago
  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.
  • ccamrobertson 4y ago
    Yes, and we would argue that has grave implications. Cash is useful for the young, the old, those who can't participate in commercial banking, etc. We don't believe that this trend will necessarily reverse, but rather that a society with no cash is risky to live in.
    • jacobsenscott 4y ago
      This is not cash though. For example you'll never be able to buy food with it, or pay your rent with it. You can't store it under your mattress for 10 years because the servers they must talk to won't be around in 10 years.
      • paulgerhardt 4y ago
        Cash in its western form has been around since the 1600’s. It’s simply a promissory note. The difference is in this case the encoding for that promise is onchain. Cash has gone through many evolutions but it started as peer to peer agreements between merchants. Now it’s peer to peer agreements between programmers. There was a bit in the middle where it was agreements between governments or banks but this is isomorphicly the same. As for buying food. Yes. One can. Has been able to for a while. The future is here just not evenly distributed: https://twitter.com/alexmasmej/status/1228771055524704256?s=21&t=LtFA_NJrdsqCsvvlxHDK1g https://twitter.com/alexmasmej/status/1228771055524704256?s=...
        • jacobsenscott 4y ago
          I could probably convince someone to barter me some food for Pokemon cards, but that doesn't make Pokemon cards cash.
• EGreg 4y ago
  How would it possibly know if the holder cut the note? What if they pasted it back together later, and passed it off?
• jameshart 4y ago
  If the value of this is locked in the scannable NFC chip… what’s the point of all the antiforgery measures on the paper?
• arcticbull 4y ago
  Secure, anonymous, peer-to-peer, self-custodial? I think you're just describing plain old dollar bills.
• lvass 4y ago
  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?
• substation13 4y ago
  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.
  • ccamrobertson 4y ago
    That's a super interesting idea. We've been somewhat purist about the notes being bearer by nature (not ideal, like digital Bitcoin, for fleeing from oppressive regimes), so any other entanglements challenge that notion. That said I could imagine a run of "bond" notes instead that rely on a multisig across notes rather than redemption at a bank or with the Treasury.
• killdozer 4y ago
  How is this better than https://www.jmbullion.com/1-utah-goldback-gold-note/ https://www.jmbullion.com/1-utah-goldback-gold-note/?
  • spicybright 4y ago
    At least with that the note has intrinsic value, theoretically.
• devmor 4y ago
  This is really cool from a technical standpoint but I don't really see a use case for it.
• formerkrogemp 4y ago
  "Hey Dad, I need $10 of Bitcoin! Why do you need $15 of Bitcoin to buy an $8 of Bitcoin charger?"
• jl6 4y ago
  Who are the classical statuesque faces in your designs? Do they symbolize anything? And is that a `hexdump -C` I see?
  • ccamrobertson 4y ago
    We used Greco-Roman god statues -- Apollo, Venus, Minerva and Neptune (some of the model statues were Greek, others Roman). We chose aspiration mythical figures to point to some deeper Bitcoin lore. I will hold off with details and let our note designer tease out the meaning there. Hmm...where? Given all the last minute touch ups to the site I wouldn't be surprised...
    • jl6 4y ago
      Thanks! The thing that looks like a hexdump is the tiny text on the note itself.
• godmode2019 4y ago
  What if your server doesn't exist in 5 years. Its not really 'offline.cash' when a user needs to ask permission to your server to access their funds.
• aftbit 4y ago
  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.
  • danuker 4y ago
    > but they died because they were too early Maybe they died because Bitcoin, a digital asset, is much easier to spend digitally than printing it and giving it physically to someone.
  • theicfire 4y ago
    https://www.reddit.com/r/Bitcoin/comments/h7nvy/bitbills_bitcoins_you_can_hold/ https://www.reddit.com/r/Bitcoin/comments/h7nvy/bitbills_bit...
• gauddasa 4y ago
  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?
• dustractor 4y ago
  Hopefully works out better than Escobar Cash ECH https://pabloescobar.com/ https://pabloescobar.com/
• Termitiono 4y ago
  That's just a joke I'm too stupid to get right? You make a physical representation of something digital which also changed denomination quite often the last 10 years? What do I do with it? 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? 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? Now Bitcoin makes even more garbage?!
  • sumeno 4y ago
    [flagged]
  • ouid 4y ago
    My favorite part is the pictures of it on the website. "Hold your corporeal money next to other real things, like pizza and gameboy cartridges and magic the gathering cards. This is a real thing. That you can own. Like this baguette, or this tamagotchi."
    • deleted 4y ago
      [deleted]
  • 40four 4y ago
    It’s not really a joke, but it is a little funny. It’s just a really fancy ‘paper’ wallet. I actually love the concept. I used to make paper wallets for myself and friends, and this is basically the best version I’ve ever seen
  • somenewaccount1 4y ago
    You missed the part where the private company 'authenticates the bill being cut in half' in order for them to surrender the private key. So, in theory, the bill has the printed Satoshi value and doesn't need a smart phone to verify. Rotlmao. In practice, the company gets hacked, loses all the keys, and now all these bills in the wild look legit but have no value. Also, they will be counterfeited like all other bills, except easier because thier not a government mint.
• ineedasername 4y ago
  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.
• formerkrogemp 4y ago
  I have a secure, self custodial note right here: it's called cash.
• dmitrygr 4y ago
  > we write an encrypted private key to the note and don't keep a copy 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)
• tinnet 4y ago
  Looking forward to the CCC talk of somebody using a homemade low powered xray machine to retrieve the code without cutting the note.
• jcfrei 4y ago
  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.
• joshspankit 4y ago
  What does the transaction look like on the chain? I feel ridiculous in taking this seriously, but it’s got me curious. 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. I do like the graphic design though.
  • jussaying2 4y ago
    Congratulations, you've just invented cash!
  • ccamrobertson 4y ago
    Depending on where in the lifecycle the note is, it's either a 2-of-2 multisig transaction or 1-of-2 multisig transaction, using only the user key in the latter case.
• hnthrow1010 4y ago
• Barrera 4y ago
  These are gorgeous and the idea of physical tokens has a rich history in Bitcoin. Some users love them but others not so much. 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. 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. Unfortunately, the page is light on details and the comments haven't answered al my questions so I'll speculate a bit. 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. 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.
  • ccamrobertson 4y ago
    It's indeed a tricky problem -- > If the issuer can always sign unilaterally Based on the construction of the multisig we never have custody over the Bitcion, even if we store the encrypted key (we don't). > If the funds can be lost through loss of user keys, then this offers little practical advantage over bill-less bitcoin There are several; easy key diversification across multiple wallets. Easy offline storage away from connected devices. Easy onboarding. It would be possible to backup the user keys on the notes independent of the note, we just believe that having them function more like cash guides the user to make choices where they are far less likely to lose them -- e.g. storing in a fireproof safe, safety deposit box, etc.
• pope_meat 4y ago
  I honestly thought this was satire at first.
• egypturnash 4y ago
  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? 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".
• Werewolf255 4y ago
  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. Top work everyone, nailed it.
  • glerk 4y ago
    I think people in this thread are taking this a bit too seriously. To me this just looks like a novelty item, more akin to an art piece than a serious technology intended to be used on a daily basis. You gotta admit it looks pretty cool.
    • soared 4y ago
      > To me this just looks like a novelty item, more akin to an art piece than a serious technology Oh boy, wait till you hear about NFTs, memecoins, and well.. bitcoin I guess.
  • la64710 4y ago
    So it is basically encrypted key stored in a micro sd card inside some printed paper. Gimmicks like this is why the whole crypto thing is all smoke and mirrors.
  • isitmadeofglass 4y ago
    Yes, but it solves the main problem that traditional dollar bills have, which is that I can’t get VC funding for handing people dollar bills.
    • biztos 4y ago
      Maybe if you could outsource the handing to a low-wage country, while still having the handees be either Gen-Z Americans or other VC-backed companies.
  • paulgerhardt 4y ago
    >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. Literally none of this is true. There's so many comments in this thread that pagination is now turned on so apologies if you didn't catch some of the explanation elsewhere. It's a synthetic polymer (not paper) that can survive heat and strong electrical fields that can (but doesn't need to be) be validated with a computer, maintains its value if the issuing party goes under (see the key rotation comments in this thread) and is recyclable. Burnable? Actually yes, at a high enough temperature (higher than linen) but it would first melt. We have previously experimented with "burn proof" polymers but found this wasn't an important metric to optimize for given the huge tradeoffs those materials come with and which our colleagues who make Hong Kong, Canadian, and Australian dollars also reached.
• kadoban 4y ago
  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. Can't even remember the name of it to be honest, wonder if it still exists.
• oa335 4y ago
  Don’t pay attention to haters, it’s sorta cool, even if it’s not the most efficient or safe way of holding Bitcoin.
• neilv 4y ago
  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... https://www.nxp.com/company/blog/nfc-gets-cheesy-with-kraft-singles:BL-NFC-GETS-CHEESY-WITH-KRAFT-SINGLES https://www.nxp.com/company/blog/nfc-gets-cheesy-with-kraft-...
• gameshot911 4y ago
  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.
• forgithubs 4y ago
• parentheses 4y ago
  Paper money that doesn’t work without computers seems like 2 SPOFs rather than one.
• ukd1 4y ago
  Does this completely supersede kong?
  • ccamrobertson 4y ago
    We've dabbled with the idea of making a Kong note using the same tech we're applying for the Bitcoin Note, but the requirement for a large fixed run of notes and the niche appeal of Kong makes this tricky. While Kong Cash notes are gorgeous, there are couple additional reasons we likely won't ever make another cryptocash note like that again: resilience over time in your wallet and the flex-PCBA manufacturing process rather than a print process (the former being far more complex with limited print detail possible). That said, we believe that we are likely still the only mass production run of flex PCBs that incorporated a full-color digital print :)
• thesausageking 4y ago
  "Copyright ©2022 Offline Cash, US Patent. No. 10,896,412" This is not the way.
• togaen 4y ago
• cyphar 4y ago
  Aside from finding the premise questionable, I do find it incredible how US-centric this is: > 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. 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.
• dropnerd 4y ago
  very cool design work. are you planning to roll out an ethereum version?
• bfung 4y ago
  I originally thought this was a joke… because normal “offline” cash that I can spend… isn’t on the blockchain… wait… LOL. 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? Lols.
• woodruffw 4y ago
  A few things that I don't understand: 1. The private key is itself encrypted and stored on the note. Where is the key encryption key stored? On this company's servers? 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? 3. What prevents exfiltration of the user key from the note?
• Uptrenda 4y ago
  >3) We only release the decryption key when someone cuts the note and reports this via an authenticated and encrypted way to our server How exactly is this step done? How can you securely verify a note is destroyed?
  • panda88888 4y ago
    Looks like there is a trace that needs to be cut. The chip probably detects continuity of the trace and reports it’s private key if detected open.
• twald 4y ago
  Ehm… side note… The notes look gorgeous
  • ccamrobertson 4y ago
    Thank you, always great to get praise from another hardware founder :)
• d--b 4y ago
  Make this for NFTs and the joke is complete.
• King-Aaron 4y ago
  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
• deleted 4y ago
  [deleted]
• rkagerer 4y ago
  I liked BitBills. They were simple to understand, and I knew the tradeoffs and where I was reliant on trust. 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.
• gloryless 4y ago
  2100 people will fall for this. We're living in a sitcom
• lewisflude 4y ago
  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. 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.
• mountainriver 4y ago
  I actually really like this, something about having a physical form to btc is appealing
• donkey-hotei 4y ago
  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 https://www.buzzfeednews.com/article/katienotopoulos/guess-whose-face-is-on-printed-bitcoin-money https://www.buzzfeednews.com/article/katienotopoulos/guess-w...
• SergeAx 4y ago
  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?