This article is the starting point of our series dedicated to our bearer crypto card: Satodime. So that you can use it to its full potential, we’re going to explain how it works, as well as how our mobile application works. You’ll then be able to use Satodime independently to store your favorite crypto currency.
Table of contents
- Introduction
- Use cases
- Prerequisites
- Create a new vault == SEAL
- Store your crypto-currencies == LOAD
- Check the balance and status of the vault== VERIFY
- Retrieve the private key == UNSEAL
- Reset a vault == RESET
- Conclusion
Introduction
Satodime is a bearer smart card that lets you exchange crypto-assets just like any banknote. Transmit it securely several times thanks to the secure chip, and unseal it easily at any time. All without the need for a trusted third party, in a perfectly simple and secure way.
Satodime is a card that works like a bank safe; you can deposit valuables in it, and only the key holder can open it.
The only major difference with a conventional safe is that the key to open the safe is not held by the cardholder. It’s held by the card itself, thanks to the secure chip. It’s a kind of transportable safe.
With a Satodime card, you can physically transfer #Bitcoin, #Litecoin, #BitcoinCash, #Ethereum or any other #ERC20 token (including #NFT (#ERC721) from one user to another (hand-to-hand). This peer-to-peer transfer remains secure and fully autonomous thanks to Satodime’s technology.
In short, it’s essentially a transferable and reusable physical wallet that can be used like cash. So be sure to adapt your use accordingly.
Use cases
To show you Satodime’s potential, let’s take a look at a few use cases:
Buying goods
You want to buy the new Tesla using Bitcoins. You take your Satodime, seal a new Bitcoin vault, get the BTC address and load 1 BTC onto it. Then you go to the car dealership and start negotiating. The dealer asks for 1.25 BTC for this beautiful Ludicrous P100D. You accept the deal and send another 0.25 BTC to your Satodime safe using your favorite Bitcoin client. You take your cell phone, scan the Satodime using NFC technology and show the dealer your sealed card safe. He can verify that the Bitcoin safe is sealed and filled with 1.25 BTC. You shake hands and give him the card. You take the car and leave the showroom in peace.
Artwork exchange (NFTs)
You’re an NFT (Non Fungible Token) artist and you’re ready to launch your new collection on OpenSea or LooksRare. You’d like to promote your Bored Punk Farmer collection in a unique and trendy way. You take your Satodime, seal a new Ethereum chest and load 1 NFT onto it. You can now offer your Satodime on your social media channels. Winners who physically receive the card will be able to verify the NFT safe and eventually unseal it to recover the private key to the Etherem wallet.
Cold storage for crypto-currencies
If you want to take your friends on a new adventure and introduce them to Bitcoin and crypto-currencies, you can offer them a Satodime card. You take your Satodime, seal a new Bitcoin vault, retrieve the BTC address and load 0.0001 BTC onto it. Give the card to your friend and tell him/her that he/she can verify the wallet’s balance using his/her cell phone. That’s great!
No PIN code required, no seed generation, no complexity. It’s simply a smart card, loaded with a few satoshis (or ERC-20 tokens) that you can transmit, repeatedly, in complete confidence.
Prerequisites
Now that you’ve understood why Satodime is a useful product, you’ll need to learn how to use it. No problem — that’s what this article is all about!
How do I get one?
- Purchase a Satodime 💳 cryptographic bearer card from Satochip’s official online store.
2. Optional: get a smart card reader to configure your Satodime on your computer.
3. Download and install the Satodime application to create and manage your vaults on your card:
· Windows 🪟 : Satodime-Tool-v0.2.1
· Linux 🐧: Satodime-Tool-v0.2.1
· MacOs 🍎: Satodime-Tool-v0.2.1
Create a new vault == SEAL
In this example, we’ll create a Bitcoin safe in our Satodime card using the Satodime iPhone mobile application. You’ll see that you can create up to 3 vaults using a single card. This means you can store up to 3 different crypto-currencies on the same card. Naturally, when you entrust the card to a third party, you part with all the assets you have deposited on the card, so don’t forget to check this point carefully.
So far, Satodime supports:
- Bitcoin ($BTC)
- Ethereum ($ETH) and the ERC-20 and ERC-721 (NFT) tokens
- Litecoin ($LTC)
- Bitcoin Cash ($BCH)
- Counterparty ($XCP)
To create a new vault, simply click on an empty vault and select the blockchain of your choice. In this example, we’ll select Bitcoin. Optionally, you can choose the network type “MainNet” or “TestNet” and also provide the entropy that will be used to generate the key pairs.
Finally, to create your Bitcoin vaukt, click on “Create and Seal”.
The application will ask you to scan the Satodime card on the back of your phone. Be sure to leave the card glued to the phone throughout the operation.
Et voilà, in just two clicks, you’ve created your first Bitcoin vault. Simple, isn’t it?
Note on entropy: the private/public key pairs stored on the Satodime card are always randomly generated inside the secure chip. As long as the vault is sealed, no one has access to the private key. To prove that the private keys have not been pre-generated during the manufacture or shipment of the smart card, and that no backdoor has been inserted into the firmware, the user is prompted to enter a random value during the initialization process. This random entry is used to provide entropy during the key generation process. When the vault is unsealed and the private key is revealed, entropy data (including the one entered by the user) is provided, ensuring that the key generation process was indeed random.
Store your crypto-currencies == LOAD
You have now created a Bitcoin vault. Vault #01 is in “Sealed” mode, which means that no one has ever had access to this wallet’s private key. You can send your bitcoins securely to this address.
By clicking on “Add funds”, you’ll be able to view the deposit address of this freshly generated vault.
For added convenience, you can display the QR code of the address. This is very useful if you want to easily load some bitcoins onto this newly generated vault.
Check vault balance and status == VERIFY
Each key pair is generated inside the secure chip and can be in one of three states at any time:
· Uninitialized: the key pair has not yet been generated;
· Sealed: the key pair has been securely generated inside the chip;
· Unsealed: the private key has been revealed.
In this example, you can see the different states of safe #3. On the left, it is sealed, meaning that no one knows the private key. On the right, it is unsealed, i.e. someone has opened the vault to retrieve the private key.
If a vault is in the “Sealed” state and the balance shows a positive amount in crypto-currency, you can safely accept, share, buy, retrieve the Satodime. This means that this particular vault contains crypto-currencies and that the private key has never been revealed.
Recover the private key == UNSEAL
If you want to recover the private key of a specific vault, you can unseal it at any time. This action is irreversible.
To do so, click on the “Unseal” padlock. This action will command the chip to reveal the wallet’s private key.
When a vault is unsealed, the private key is made available to the user and can be retrieved by clicking on the “View key” button of the corresponding vault.
Once the private key is exposed, it is no longer protected by the secure chip, and any assets associated with the corresponding address must be transferred immediately to a new address. This is usually done by transferring the private key to a software wallet (e.g. Electrum or Metamask).
YOU SHOULD NEVER ACCEPT A SATODIME FROM SOMEONE IF A VAULT IS UNSEALED!
Indeed, if the person who entrusted you with the card already has access to the private key, there’s nothing to stop him or her from importing this key into another wallet and getting their hands on the assets linked to that wallet.
In the same way that you wouldn’t allow the vendor of your alarm system to keep the code to gain access to your home, you shouldn’t accept a crypto wallet whose private key has already been revealed.
The good news is that it is possible to reset a Satodime card!
Reset a safe == RESET
One of the great advantages of your Satodime card is that you can reuse it indefinitely. For a given vault, the transition from one state to another always follows the same cycle: ‘Uninitialized’ => ‘Sealed’ => ‘Unsealed’ => ‘Reset’ => ‘Uninitialized’ => … Cool, isn’t it!?
Once a vault has been unsealed and its contents transferred, you can reset the location to its “uninitialized” state and start a new cycle.
Press the reset button to remove the vault.
Make sure you have saved :
- The public key (pubkey) and wallet address;
- The corresponding private key.
Because this action will reset the vault and therefore the public information (address…) and the corresponding private key. Once reset, all data in the vault will be deleted.
And that’s it, vault #3 is now free to use. The status of the svault is “Uninitialized” and you can use it again.
Conclusion
There’s nothing like Satodime on the market!
Satodime lets you store, verify and physically exchange crypto-currencies and other tokens such as NFTs.
Satodime is:
- Multi-crypto: your Satodime card supports a wide range of crypto-currencies. You can generate private keys for Bitcoin, Litecoin, Bitcoin Cash, Ethereum and ERC20 tokens. The card supports tokens based on ERC20 and ERC721, with many more to come… You can even store your favorite #NFT.
- Multi-vault: you can generate up to 3 different vaults. This allows you to manage several private keys at once. For example, you can safely store a few Bitcoins, a few Ethers and your favorite altcoin in a single Satodime crypto card. Satodime supports MainNet and TestNet coins and tokens.
- Safe: your Satodime is not just a storage device. The card incorporates an EAL6+ certified chip that acts as a secure element (SE) to handle your keys (public and private) with care. Thanks to cryptography, your private keys and sensitive information are safely isolated within the secure chip and never leave it.
- Trustless: private keys are strictly sealed in the secure chip. You don’t know the keys until you unseal the vault. The color of the vault changes from green to orange when unsealed. Just like a banknote, it’s never been easier to transfer crypto-currencies securely from hand to hand.
- Reusable: there’s no need to break the device to use it again. You can retrieve the private key and reset the vault again and again.
And best of all, Satodime is open source!
