The organization that issued them should guarantee their redemption at par value in the case of presentation for payment.
Tangem Notes are completely trustless and decentralized beyond the multi–party security audit — in fact more trustless than any other current way to store Bitcoin. The chip is a tiny standalone HSM designed entirely for mission critical security applications and is completely air–gapped with just a tiny API to access it. You don't need anyone to guarantee their redemption as you can redeem Tangem Notes yourself with an NFC phone using an open protocol — or our reference apps (iOS open–sourced, Android to be open–sourced).
If it requires an NFC connection to chech the current balance, why the banknote is different from a mobile wallet?
Tangem Notes compare to mobile wallets same way fiat banknotes compare to mobile banking apps. Except mobile banking actually has banks behind them, while mobile wallets are relatively insecure. For most people without a background in engineering and security Tangem Notes are by far the safest way to store Bitcoin right now.
You do a beta test with bitcoin and after you can start to work with national currencies?
We want entrepreneurs, financial organizations, and governments to use the base Tangem technology for thousands of different tokens, currencies, and applications. It looks like Bitcoin will be the flagship for at least a long while.
The problem I see with that is that they are selling them for $199 for a pack of 10 unloaded cards. So who is going to want to hand over a device worth $20 when they spend $100?
The price tag is just for a limited edition Pioneer Kit for people who want it now, while we're rolling out normal distribution channels around the world, which takes time. The Pioneer Kit also comes with additional features which makes it useful as a highly secure hardware wallet. For retailers the cost of a basic Tangem Note is designed to nicely fit within their margins.
what happens if I have this banknote (card) and by the time when I want to hand it over, the secure chip fails inside?
The chip and firmware inside every Tangem Note is designed to be secure not just against hacking, but against sporadic failures. The secure element should survive magnetic fields and pulses as well as cosmic rays better than most other electronics. It is rated for at least 40 years in operation, but is expected to last much longer than that. We apply extreme mechanical and RF testing, targeting CQM and other standards compliance.
In short, value stored on Tangem Notes should be orders of magnitude safer than that on exchanges, cloud wallets, hot wallets, cold wallets, or paper.