Topic: [04-05-2018] Physical Bitcoin Smart Banknotes Launched In Signapore (Read 280 times)

This is a very interesting form of money. I understand that the firm Tangem has issued its banknotes in bitcoin to the very Bttcoins that it had. That is, in this case, it acts as a guarantor of the availability of these Бткoинoв as well as the state guarantees acceptance of its national monetary denominations by any state banks for payment. Therefore, the firm Tangem here is obliged to redeem its banknotes in bitcoin when they are presented for payment. I think that in the future there will be different variants of bitcoin and other types of money and securities.

You're drawing your perceived contradictions from using the word «trust» with materially different connotations for a rhetorical effect. Compare:

1. I informedly trust this airplane not to crash, because: authorities are certifying it, Boeing is a serious business, engineers are not murderers, there are many failsafes, planes rarely crash.

2. I blindly trust this stranger to hit an apple on my head with a gun from 30 feet, because: they say they can, how hard can it be, why would anyone want to shoot me, it's so cool.

Tangem was carefully designed and built into #1, Casascius, in any engineer's eyes, is #2.

Our goal is to structure the product in a way where we can't do anything harmful, out of malice or stupidity, even if we really wanted to — including the edge cases of a sudden dissolution of the company or even hostile takeover. Every product will still function forever, and be secure for its lifetime.

To this end, we already closed the trust loop — by keeping the product simple (relatively tiny attack surface) and bridging multinational certifications with independent audit of unquestionable integrity on top of a simple open protocol and reference implementations.

In the consumer space, there's no hardware product that even claims this level of security, much less achieves it.

You're contradicting yourself perfectly. It doesn't matter how simple the firmware is, it's proprietary, and that means users cannot verify your claims without spending the BTC from these notes.

Tangem notes don't need "independent certification" or "manufacturer attestation" if there's no need to trust anyone. That literally means customers are being invited to trust your attestations and certifications.


A significant part of what makes Bitcoin valuable is that anyone can verify the validity of a payment, not just a company paid by a manufacturer to do so. The previous physical Bitcoin producers (or at least Casascius anyway) were very upfront that trust was essential to their product, that made it easier to trust them. The fact that you at Tangem either don't understand that, or are wilfully misrepresenting the fact, makes it much much more difficult to trust you or your notes.

The chip is highly secure and independently certified. Our proprietary firmware is beautifully simple and audited by Kudelski Group, look it up. https://twitter.com/kudelski/status/994105585825144832

The chip and firmware guarantee no import or export of keys is possible — the chip creates it's own unique private key and can never disclose it. There's manufacturer attestation mechanism on the same secure chip to prevent any chance of counterfeits. You don't have to trust anyone.


Correct, there's nothing between the chip and the blockchain, no company can control it — just an open NFC protocol and our open–source reference apps.

Hmmm, well it could be worse.

But still, there is only one way to discover whether Tangem Notes are either counterfeits (or if Tangem are simply flashing memory chips with the same keys more than once), and that's to spend every Tangem note before you accept it from someone else.

I can imagine this working well:

Store: "So, let me just spend this Tangem note to an address I control, then I'll give you your goods"
Customer: "Uh, how about no?"

You can't really give a Tangem note to someone else, there's nothing to prove that there isn't another Tangem note that has access to the same private key. Except Tangem promising there isn't, of course.

In Tangem We Trust!

The site recently added more information, including this:


It looks like the chip will sign transactions, so it is like a hardware wallet.

If I understand this correctly, the chip within the card can be read by a mobile phone and the mobile phone is connected to their APP which links to the Blockchain. So you are not accessing the companies own ledger, with some tokens linked to the card. You have access to the coins that are linked to the Blockchain.

You need a phone with NFC enabled to access the information on the card.

I have found no information on how they are supposed to work. My guess is that the chip will cryptographically verify its authenticity and it represents some amount of BTC held by Tangem. That would not be very appealing to me but I guess we'll just have to wait and see.

Going back into the past where people do keep saying and hoping that bitcoin would become a currency where comes to a point that it do have physical form and now it do happen,not directly as a coin but a banknote which I have seen most people above don't really like this thing even I neither. Volatility would really be the main problem on here and I doubt people would just collect those things rather than on spending them since they do know on btc earning potential.

So the blockchain address is accessible, but the private key is not?

If so, there's a flaw in your model, and you've misunderstood how cryptographic keypairs work. There's no way for anyone holding a Tangem Bitcoin note to prove that they own the money at the respective Bitcoin address on each note.  

How can you prove that the money at these addresses is money sent to the address by Tangem, and not just any random bitcoin blockchain address with 0.01 BTC contained? How can people be sure Tangem didn't use the same address twice, three, four or a hundred times on different notes? Are you going to release videos of Tangem workers sending each transaction to every Tangem note ever made? Will that be enough for people to trust the funds are really unspendable by Tangem, or that you aren't re-using addresses over multiple notes?

Who wouldn't like the collectibles? That said, for people who cannot be at ease because of the intangible nature of bitcoins, this should be a good option. Bitcoin bearer bonds, in the form of USB sticks, have been around for quite some time now. But people are more comfortable with coins and notes to represent money.

We need to take crypto to the billions.


Tangem Notes are not for small transactions — they are more likes USD 100 and EUR 500 bills, for larger transactions and savings. Technically ever Tangem Note *is* a very secure cold wallet.


Only the chip creates and controls the private key, it's impossible to export or import the key. The firmware is audited and the chip is highly certified. The manufacturer is not in control and even if Tangem disappears or is taken over, the notes will work safely, forever.

Sounds interesting, but still got a question "Why??"

I'm a bit divided here. First I think that using a mobile wallet on a phone is much simpler that making payments with these notes. People can just charge their mobile wallet, so that they don't need to be carrying a lot of money "on their phone", and they can then spend them just by scanning the QR code. It's much easier than carrying bills. Of course that I do understand that for some users, specially the elderly, this new way of spending money could be harder, so using this Physical Bitcoin system could help them. I don't see a great future on them, besides helping on a transition phase. They could also become some kind of cold wallet, so maybe they are aiming for that, I don't know.

I prefer the old-fashioned virtual bitcoins I might fall in love for those collectibles (Casascius coins?) but not for this. It seems though a good way to bring new people in.

Ok, I am intrigued by this. Will this work like the old Casascius physical bitcoins, where you have the private keys stored on the physical coin or card or will this be administered by a third party and this card will just link you to their internal database via the Semiconductor’s S3D350A chips?

So will the manufacturer of the cards be in control of the private keys or would the private keys be stored on the chip? The ownership of the private key is the most important factor in this technology. 

i guess that's one off chain solution to the problem
I was wondering how you would verify the validity of the wallet, apprently you could check it instantly on your phone through the nfc. I read more on yahoo

https://finance.yahoo.com/news/physical-bitcoin-banknotes-launched-singapore-140230555.html

I think these notes will be good gift for the people who still don't have Bitcoin wallet. They can help attracting new Bitcoin users.

It's not going to work well for every day transactions, where in any case, we have applications (wallet clients) making it easier than ever to transact with others. I just scan the QR code of the receiver, send the funds, and it's done. I'm not going to take anything with me other than my phone, which is the only thing that we need to conduct payments. I'm quite sure that aside from people potentially using it as some sort of a hardware wallet, there is no real use to gain. From there I wonder how long they will continue to produce these 'bills'. I don't see any viability in this, and I hope that the manufacturer realizes that as well.

Banknotes, face value of 0.01 and 0.05 bitcoins, this is something new. However, so far much in their release and use is unclear. These banknotes, it turns out, have signs of ordinary money, crypto-currencies, bills. With this approach, it is possible to create crypto-currency banks and they will be able to provide various services in crypto currency using such banknotes. In this regard, we say that we are only at the beginning of the development of the crypto currency. There are many more surprises ahead of us.