Quote from: nick_nick on May 04, 2018, 04:37:41 PM

I wonder if they are going to keep the private keys of these notes themselves or what.

It's impossible for the manufacturer or anyone else to ever see the private keys they are created and protected by an independently certified chip and audited firmware.

Quote from: Juggy777 on May 04, 2018, 04:30:46 PM

who is guaranteeing them

what rates

Nobody has to guarantee the value inside Tangem Notes it is real Bitcoin inside and you can easily verify it with any NFC phone, and extract it to another wallet if you're sure you don't need the note anymore.

Quote from: Crypdon on May 04, 2018, 04:16:36 PM

I guess this is more like a voucher than actual bank notes as they can only be used once unless you re-credit it with more bitcoin.

Each Tangem Note can be circulated forever it takes a fraction of a second to validate it with any NFC phone. Tangem Notes are exactly like actual bank notes, only better there's no risk of counterfeit, no risk of government devaluing your currency, and you can extract the value via NFC if you urgently need to send it digitally rather than physically.

Quote from: ETFbitcoin on May 04, 2018, 04:16:06 PM

That's good idea considering it's convenience. But i wouldn't buy/use this banknotes since there's no way to verify whether They keep the private key or not.
Also, passing private key instead make a transaction is risky, especially if they really keep all private key of their banknotes.

If this "banknotes" is 100% open-source and don't have any balance when issued, this might be great product.

We would never make Tangem Notes if there was no way to verify that it is impossible to have a copy of any private key

The chip creates and protects the keys, it's a highly certified secure element with an independently audited firmware. We cannot open source the firmware at this time, but a summary from Kudelski Security will be published when they're done with their analysis. However, we are opensourcing our reference app and the protocol.

You'll be able to get Tangem Notes without value on them. For most people, they need them loaded with Bitcoin already.

Quote from: badakjawa on May 04, 2018, 03:21:34 PM

if bitcoin has a physical shape like fiat, i think the bitcoin character is gone. and will certainly reduce the quality of bitcoin value.

If we're successful reaching a billion people with Tangem Notes, BTC will be valued at over USD 1 million in current terms. Of course, governments will start adapting long before that.

Quote from: stompix on May 04, 2018, 03:19:17 PM

So you can't extract the coins from the banknotes, and the only ones that can do this are the the ones issuing those....
It smells fishy, how can you be sure there aren't 5000 notes with the same address ?

Of course you can extract Bitcoin from Tangem Notes, you don't need their private keys for that, just a special signature. The chip cannot import a private key, only create its own unique one. The firmware is audited.

Quote from: Jonsnowstark on May 04, 2018, 02:36:10 PM

Once it has coins or notes, there should come a central agency that keeps track of ot.

Tangem Notes are completely decentralized and do not need the manufacturer, an issuer, or any third party to keep track of it. The value is inside them on a secure chip and they can be redeemed back to blockchain at any time via NFC the same way you validate their authenticity and current value.

Quote from: Xester on May 04, 2018, 02:26:41 PM

This is a good way of circulating bitcoin since it will bridge the gap between bitcoin and the areas without internet access. But the problem is that if those producers of those bitcoin smart banknotes are going to print notes more than the number of bitcoin they have in store.

Fortunately you don't need to trust the manufacturer the Bitcoin value is inside each Tangem Note, can be verified over NFC and extracted at any time.