Show HN: The Bitcoin Note – Secure, Self-Custodial Bitcoin Wallets in Cash Form
offline.cash
offline.cash
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/ to learn more and reserve a spot in line for our release later this summer.
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.
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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?
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.
Does this mean that your private servers have the ability to re-key notes? What prevents someone from scanning the chip or storing the user key that they generated, handing the note to someone else, and then walking around the corner and immediately using the scanned information to re-key it?
Without understanding more about the technical details, this feels like unless a user is using an app to re-key immediately at the time of transfer that it's significantly less secure than normal cash. I guess I'm not completely clear on what you're doing with user keys.
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> Because with a phone alone they need to store their keys locally.
But they have to do that here too, or is the assertion that they don't need to back up the user key necessarily and that it's not secret? Is the user key just plain-text readable?
If the user key is accessible from the chip just via scanning (not cutting), and isn't a user-defined secret that only they know (which seems like would require some form of backup), then does that mean an attacker can just walk past my wallet with a reasonably powerful RFID reader and then rekey every single one of my bills?
Can you tear the note apart and have it work too, if you don't have scissors on hand for example?
Maybe you can sell a kit that comes with the notes and a special cutter, like a cigar cutter with a box
Doesn't sound very "self-custodial" to me.
In a safe place, like a wallet? This seems dramatic unnecessary. You can lose cash. And it’s measurable how much easier it is to lose paper money compared to a phone.
Hard cash went electronic. Why would electronic cash go hard?
You can do cold storage by securing seeds on metal, such as titanium, or any robust material you like.
Top work everyone, nailed it.
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.
Even with all that being said, taking you at face value, it's bringing bitcoin into yet another format you can lose, and with its own tidy expiration date. Oh and let's not forget the extensive discussion of cutting or otherwise rendering the note useless on redemption. Are we supposed to believe this is an art piece or a serious monetary instrument. Traditional cash happens to be both and I can buy donuts with traditional cash, sans phone no less
Gimmicks like this is why the whole crypto thing is all smoke and mirrors.
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.
Oh boy, wait till you hear about NFTs, memecoins, and well.. bitcoin I guess.
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".
We highlight the low serial notes as we know numismatists like to collect this sort of thing.
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?
Guess I am just curious if the same kind of effect was observed, I suppose banks would have been trying to "secure their spot" for some first release of $CURRENCY notes/coins? Hard to imagine Joe Homesteader lining up at 9AM.
Its a small community but they’ve been around since the Casascius days, long predating crypto asset securities (which predates the ICO)
I think there are some good arguments for stablecoins in markets that desire dollars, but they are hard to get -- or for high denomination notes, however, we suspect there would be additional regulatory challenges here.
Honestly: Spending money like cash and using a secure wallet on my phone is already very very easy. Why would I want to go through these extra steps?
If the ONLY answer is "Because it is Bitcoin" then you might have a problem.
There is no particular reason to think the same issues would apply to "minting" a private currency which did not consist of metallic coins or incorporate any "patriotic" imagery.
[0] https://casetext.com/case/united-states-v-von-nothaus?q=Unit...
1.
> Von NotHaus designed the Liberty Dollar currency in 1998 and the Liberty coins were marked with the dollar sign ($); 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_i...
3.
This isn't a new currency, it is a new key storage format for Bitcoin.
That said if they can find an initial group of super enthusiasts it might go well. Maybe Nayib Bukele would be interested in the technology to license it to El Salvador.
Everyone I know who has done an exit got told there would be no market for their product. Just follow your vision and ignore whatever people say.
Sounds like survivors bias in a few words. Presumably the folks who had no market fit never got anywhere near an exit? I'm not sure I'd use this metric as a guide telling me to ignore the market.
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?
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.
Wondering if this requires a money transfer agent license in the US, since you are holding funds in custody and issuing scrip?
It was a pleasure to work with an actual banknote designer, Tom Badley, to accomplish this.
¹Does anyone know of a country use portrait layout?
Maybe they died because Bitcoin, a digital asset, is much easier to spend digitally than printing it and giving it physically to someone.
Defeats the purpose.
That's where the money is.
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.
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.
You spend and transact mostly in fiat, you borrow in fiat. You save some percent of your earnings in more finite stores of value (you and everyone else already do this so the concept is not controversial).
The idea is explained here: Ctrl + F "two monies"
http://fofoa.blogspot.com/2011/05/return-to-honest-money.htm...
You're honestly going to claim that an asset that is down more than 40% YTD is a hedge against inflation?
It was farmer that turned his farm into direct sales, used an Uber like service to deliver and used DASH as point of sale and store of value...is what I did illegal??
There are a ton of uses cases out there where blockchain tech can provide a faster better solution, not every single case but it's there.
Even the 'criminal' side is nothing compared to the USD and how it's used. That same argue applies even stronger to fiat currencies.
A bankless note isn't a new idea, ops solution is novel and well thought out and there are markets that it solves pain points.
Ordering food online vs. Terrawatts of energy wasted, Asics hardware and GPU prices and the created co2 of all of that.
Mmhhh difficult very difficult
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.
Yes, that's a good thing.
> Someone enlighten me on the merits of this idea.
Currency that can't be manipulated or devalued by the state or central banks. In other words: eliminates the potential for exactly what's taking place worldwide right now.
The idea that the US Dollar is the eternal pinnacle of stability always seemed naive in principle, but now its clearly naive in practice.
Where's the merit?
In 2011, you could buy coffee and pizza w/ BTC (at non-conformist boutique shops but still). Now, not even those stores would accept it as a method of payment, and you'd be stupid to spend it on goods and services anyway, because BTC's value is wrapped up in the idea that it's a 'digital asset' instead of a currency.
I identify as a hacker, and I don't think all things should be programmable. Votes should not be programmable or hackable. I'm almost certain that at certain point money shouldn't be either, given how rife the abuse can be.
Or Turkey, who's inflation is around 70% right now.
Given that E2EE encrypted messaging apps such as Signal give criminals, extremists and scammers a hiding place such that the messages are totally unreadable by anyone else, does that mean we should tell Google and Amazon to ban Signal off of their servers because they are enabling such a communication service that benefits these criminals, extremists and scammers?
Also how does one 'hide' their transactions on a transparent ledger for everyone to see and trace even if they do use it for ransomware or illegal stuff? Is that why regulators haven't banned those cryptocurrencies yet and instead have targeted privacy-coins in new regulations requiring exchanges to de-list them? [0]
Seems like Stripe [1], Moneygram [2], Checkout.com [3] etc still seem to see that some of them have a use case. Perhaps that explains why they also waited for regulations before proceeding to use them [0].
[0] https://www.europarl.europa.eu/news/en/press-room/20220309IP...
[1] https://stripe.com/blog/expanding-global-payouts-with-crypto
[2] https://www.bloomberg.com/news/articles/2022-05-29/moneygram...
[3] https://www.checkout.com/solutions/crypto#stablecoin
[4] https://www.whitehouse.gov/briefing-room/statements-releases...
This just keeps getting trotted out again and again on HN as if it were a dying circus horse, but with no real merit. Even analysis by companies that spend all day, every day tracking cryptocurrency use and transactions estimate that only something like 2% of them are criminal. Even if we add in fraudulent/criminal funds that were laundered well enough to hide their origin and purpose from these tracking services, the percentage is still almost certainly a small minority.
Add to that a couple things: First, that not all "criminal" transactions are morally wrong just because they're illegal. No doubt there are anti-Putin Russians right now trying to get their money out of country with crypto and breaking a law or two. Are they scum?
Secondly, yes, there are many, many normal people using crypto for many things. I personally know many who do this, for work payments, difficult transactions because of some regulatory bullshit, remittances and even in one case as payment for contemporary dance services while living overseas. Anecdotes, but I have no doubt that they're extremely widespread, because my friend circle isn't one of crypto bros and money launderers. It's of ordinary people.
How fucking tedious to see a so-called hacker site shit so much and with so much categorically dismissive ignorance on something many of its readers emotionally dislike.
Here we are 40 years later communicating with computers. I wonder if in 40 years someone will read your comment and wonder how clueless some were in this era.
That reminds me of a line from a track by Apollo 440:
"Mick Jagger came up to me and I said 'I've seen the future' and he goes 'Yeah, if there is one...'".
Hindsight is 20/20, so of course someone will still make that mistake 40 years down the road. We can barely predict with any meaningful accuracy what will happen next year. The idea that we can predict 40 years out is the very height of hubris.
1. That people have been wildly wrong about various technologies before is not evidence that a given specific technology will succeed.
2. Many critics don't doubt the technical capabilities but instead worry about the social harm of systems developed using cryptocurrencies.
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 ?
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.
I wonder if they have an office in Hong Kong or something.
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.
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?
> 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.
> 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.
So, would this require the full balance of the note effectively to be “spent” and sent to a new multisig UTXO? Wouldn’t you also need access to the decryption key from your server in order sign with both signatures? And who pays the TX fee? Is all the key rotation work done on your servers?
Also, in order to rotate the key, a user would surely need a separate networked device able to interact with the note. I imagine one would also need to install your specific app as well.
Would there be an open protocol by which a person could perform key rotation if you go out of business and shut down your servers? If your servers go down, I can’t think of how there would be any way for a user to rotate the user key.
How are you paying to keep the lights on so that these notes keep working though expiration? You all need a revenue source, but there isn’t anything on your website that indicates how you would make money.
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.
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
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
A few reasons.
First the company. The fact that startups have realised a future of cash involving different hybrid physical technologies is important. Activity in this space shows that people take cash and its unique social properties seriously and will invest in it.
Secondly, the advance in cash technologies generally. Super thin "smart textiles" open up a new world for cash. If you think about it the technology that already goes into bank notes is amazing, but it's mostly aimed at anti-counterfeit. We had a brainstorm over here to few months ago to talk about hybrid physical cash. Ideas like using e-ink to display the current stored value, "paper" notes that could be debited, zero knowledge proofs to show the bearer has funds and title while both parties remain anonymous, ways to turn GNU Taler into hybrid cash, "contactless cash"... and much more.
Lastly, while I am not a fan of Bitcoin for environmental reasons, I think that visible/tangible forms of cryptocurrency are an important piece of the jigsaw in bringing widespread acceptance and usage of next generation cryptocurrencies, because they have important social implications for freedom and democracy.
As it is, it may not be a success (the phone verification is already a show-stopper for me precisely because I want digital cash that works independently of smartphones) - but first movers lay the groundwork for the future, so I'll be watching this.
Can't even remember the name of it to be honest, wonder if it still exists.
If you want to give someone bitcoin, just send some over lightning.
No need to add complexity and trust.
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.
A bit cumbersome but your criticism about trust is incorrect.
We don't store key material. We have 0 capability to spend any Bitcoin from the notes.
There's the centralized trust... How can you prove this?
There is no singular idea of crypto currencies. You have ideas ranging from BTC to USDC.
Why? They go after people copying bits after all... i.e.: movies
How can you know someone hasn't transferred the money out of their bank account when they hand you a check?
1) Credit cards with transaction fees (which crypto people hate) that protect against this and have replaced the needs for checks
2) You take checks from people you trust
3) You have banks that compete with each other for storing your dollars and provide services to protect against fraud.
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.
> 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.
This definitely seems more convenient than performing a 10m blockchain transaction. But what's the value prop over USD cash? Just novelty?
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.
What's your business model? Do you plan to recoup costs by selling the physical notes, or is there some other plan?
What percentage of your orders come from such disadvantaged regions?
For folks who want to hold/save/gift Bitcoin over USD, this is an easy way to do it.
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.
isn't that a counter to the whole point of a cash-currency?
We will have iOS and Android apps available (and we will open source them for peer review as well).
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.
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.
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).
Do they lose their ability to be reclaimed?
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.
> 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.
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?
Once the trace is cut the app can report that fact to us at which point we release the decryption key.
How exactly is this step done? How can you securely verify a note is destroyed?
(Either way, thank you for your service!)
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.
We don't believe that this trend will necessarily reverse, but rather that a society with no cash is risky to live in.
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.
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.
Nothing 'wrong' with it, per se. But the whole concept reads like a bad Saturday Night Live skit.
> we write an encrypted private key to the note and don't keep a copy
https://www.nxp.com/company/blog/nfc-gets-cheesy-with-kraft-...
Its not really 'offline.cash' when a user needs to ask permission to your server to access their funds.
I love it!
In other words, this whole scheme depends on the NFC chip doing exactly what it claims to.
This is true of the US dollar as well if you look at a 100 year time span.
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!
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.
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.
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?
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"?
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".
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.
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.
And is that a `hexdump -C` I see?
Hmm...where? Given all the last minute touch ups to the site I wouldn't be surprised...
The thing that looks like a hexdump is the tiny text on the note itself.
The "puritanical" foundations of the US had _tons_ of speculative financial instruments, including the colony/state/US currencies in their early years/decades.
having the "cash" part might be a bit confusing too.
I could definitely see this being used at Bitcoin meetups or other crypto-events
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.
And what is a "sewer" in your world? (Edit: I think it's a typo for "server.")
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).
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.
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.
Celebrating drug runners, malicious state actors and pirates, and environmental disaster.
This is not the way.
Just use Bitcoin Cash.
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
I like the concept of multisig being indistuingishable from single sig or other scripts.
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 :)
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?!
"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."
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.
> 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.
Me neither, I’m genuinely confused
Where did you read that? I can't find it on the website.
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.