Tangem is a new smart card technology based on a breakthrough in microelectronics achieved in 2017. The technology allows to store and carry cryptocurrencies on physical plastic cards with a chip and NFC antenna inside.
Tangem Notes are similar to banknotes, like $100 USD or $100 SGD or €100 EUR, but instead, they carry a fixed amount of cryptocurrency, like ฿0.01 BTC or Ξ0.5 ETH — on a special chip inside, called a «Secure Element».
As with traditional banknotes, Tangem Notes are not controlled in any way by their manufacturer and are completely and forever under the full control of whoever holds them physically.
Tangem Notes are the easiest and most secure way to acquire, secure, store, and transfer cryptocurrency.
You can purchase Tangem Notes at select retail locations around the world. As of June 2018, they are limited to a handful of countries. A wider rollout is planned through 2018–2019 with vending machines, ATMs, and money exchangers offering them in parallel with more retail outlets.
Tangem Notes have been developed and are manufactured by a Swiss company, based on technology from Samsung and Arm (SoftBank). The security and correctness of Tangem technology are audited by the Kudelski Group, a listed Swiss security company.
Tangem released Tangem Access for Android and Tangem Lite for iPhone — apps that help validate the value and authenticity of Tangem Notes based on the latest top–grade cryptography and security mechanisms.
Tangem Notes are the simplest, most secure way to hold cryptocurrency. If you don’t need to sell them right away, you should just store them in a physically secure location, like a safe, or a safety deposit box.
You can physically sell or give a Tangem Note to anyone — they can verify the authenticity and value with their own smartphone.
A Tangem Note is a great gift to anyone who might be interested in or could benefit from cryptocurrencies, which we think is everyone.
At any point, you can extract the whole value of a Tangem Note using the official Android app and deposit the value into any cryptocurrency account. For safety, this requires you to hold your Android phone carefully against a Tangem Note for one or two minutes
This security delay prevents other people from easily «extracting» value from your Tangem Notes when you briefly show your notes around. If you give your Tangem Note to a stranger and leave it out of sight for more than two minutes, you should always validate it when they give it back to you — in case they extracted its value.
After extraction, a Tangem Note is basically empty until reactivated through a special process.
As with traditional banknotes, Tangem Notes have to be kept physically secure at all times. The whole cryptocurrency value is always on the chip inside and cannot be accessed without the note. If you lose a Tangem Note, you lose the value.
The electronics inside Tangem Notes is designed to have incredible resilience against attacks and wear. On top of that, every single note undergoes comprehensive testing during and after manufacturing. Every time you validate a Tangem Note, it checks internal consistency and at the slightest suspicion of something going wrong, will ask you to extract its value.
Tangem’s internal standard is less than one failure case per billions of cards. Independent lab test results are available publicly and upon request.
While Tangem makes no further warranties and representations, you can mail your Tangem Note to our offices around the world — if our labs are able to extract the value or determine that there was a loss of value due to an unknown manufacturing defect, we’ll work with you directly on a case by case basis.
Technically every Tangem Note is a separate, highly secure hardware cold wallet that is fixed to a certain cryptocurrency and can hold one private key at a time.
Who knows the private key?
You can neither import a private key into a Tangem Note, nor export its private key, so it’s completely impossible to have a copy. The architecture of each Tangem Note guarantees the chip inside is the only place in the Universe where its unique key is located.
You can technically send more funds to a Tangem Note. When extracting the value, a Tangem Note may limit the transaction amount to the face value, although as of June 2018 there is no such limitation. For best results, you should never top up a Tangem Note to a value above its denomination.
A Tangem Note has a limited number of transactions permitted, with the basic version limited to just one. Unless clearly identified as «reusable» in the validation app, you will not be able to use it after extraction at this time.
In the future, a newer Tangem Note may restrict extraction to only the full face value. You can currently extract a smaller value.
Tangem Notes optimized for physical transactions and maximum security in wide circulation. It is designed to be fully trusted even when received from untrusted sources.
Ledger and Trezor are optimized for digital transactions and are only truly safe when they are in your uninterrupted physical possession. Multiple and continuing security breaches show that you cannot fully trust popular hardware wallets received from untrusted sources.
Tangem Note is made to be easily usable by any consumer with or without prior experience in cryptocurrencies or technology.
Tangem Notes can sign any transaction sent to them by the app. When a fork happens, either the reference Tangem Access app will be updated to support extracting the new funds, or the fork itself can release its own app to do the same.