Blockstream Green Wallet on Liquid

Blockstream Green users can now store, send, and receive Liquid Bitcoin and Issued Assets on the Liquid sidechain.

You can create your 2-of-2 multi-signature wallet with 2FA protection, just like you would do on Bitcoin mainnet. Hardware wallet support will also be coming soon for those looking for extreme digital asset security!


Setting Up a Liquid Wallet

Your privacy is preserved, while your funds are 2FA secured

The Green server is able to authorize and sign your transactions – upon 2FA verification – without knowing anything about the asset or the amount you are sending, or receiving.

The only information available to Green servers is the list of the confidential outputs you own. These outputs are served to your wallet, and only the client on your device is able to unblind these outputs and to compute the total balances of your assets, or to create transactions.

Switch Network to Liquid

To create or restore a Liquid wallet, change network by tapping on the network name in the center of the landing page e.g. Bitcoin in the image below.

Note

If you have an existing wallet protected with PIN, tap on the back arrow on the top right to reach the landing page, or switch network from settings after login.

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Select Liquid among the available networks and then tap on the Save button.

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Then tap on Create New Wallet and follow the process to create a new wallet, just like you would do for a standard bitcoin wallet, or tap on Restore Green Wallet and insert a mnemonic for a Green Wallet you previously created on Liquid.


Basic Usage

Logging In

When opening the app, you will be presented with a login screen prompting you to input your PIN for the Liquid Network (or for the last accessed network).

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Attention

If you have forgotten your PIN, you will need to enter your 24-word mnemonic to access your wallet. After you have done this, you will be prompted to create a new PIN to easily access the wallet you just restored.

You will also need to access your wallet with your mnemonic if you or someone else has incorrectly entered your PIN 3 times in a row. In this scenario, your app will reset your PIN and require your mnemonic. This is a security feature to prevent a malicious party from continually guessing your PIN until they get it right.

Balance and Transaction List

The main screen you will be using in Blockstream Green will display your wallet’s balance in Liquid Bitcoin (L-BTC) and its approximate value in the reference fiat currency you selected from settings.

Directly below this will be the send and receive buttons.

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Beneath these, you can find a button X assets in this account, tap on it to go to the asset list.

You can also view from this screen all of your wallet’s incoming and outgoing transactions. Transactions are listed in reverse chronological order, starting with the most recent transactions at the top.

You’ll be able to see the date, time, amount, and confirmation status of any transactions. Transactions involving assets other than L-BTC will display a 3/4 characters ticker next to the amount, depending on whether the issuer registered his asset on the Asset Registry.

You can also select any transaction to get more information about it, such as the assets involved in the transaction, or the Transaction Hash, which can be used as a proof-of-payment.

Asset List

From this page you can check the balance of every asset you have in the account you navigated from.

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Depending on what you possess you may see mainly 3 types of issued assets:

  • L-BTC, the Liquid Bitcoin native asset, 1 L-BTC corresponds to 1 BTC thanks to the peg-in mechanism.
  • Labeled assets with human readable names, you can check more info by tapping on the asset card to see the asset details. Only assets submitted by their issuers to the Asset Registry have human readable, non-editable labeling data by default.
  • Unlabeled assets identified by a 64 hexadecimal characters-long string, and with no denomination Ticker. In the next upgrade you’ll be able to customize these “raw assets” with labeling data of your choice by tapping on the asset card to edit the asset details.

Asset Details

Depending on whether the asset’s issuer registered the asset or not, you will see the non- editable asset data or just the raw identifier of the asset and the customizable fields to label the asset yourself.

Registered Assets

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Here you can see a series of metadata defined by the asset issuer:

  • the official Name of the asset,
  • the Asset ID, a 64 hexadecimal characters long unique identifier of the asset, used on the network to identify the asset,
  • the Total Balance of the asset that you currently own in your wallet,
  • the decimal Precision, which defines how many satoshis of an asset should be interpreted as a whole unit. A 2 decimals precision would imply that 199 satoshis of an asset should be displayed as 1.99. Your wallet already displays all the amounts of each asset using the precision specified under this field.
  • the Ticker is a 3 or 4 characters shortening of the asset name, used to denominate all of the amounts of this asset with a recognizable abbreviation,
  • the Issuer domain, which is used to tie together all of the above information to the issuing entity that also controls the domain submitted to the registry. This information is critical for the user to visually validate that an asset with a certain Name and a specific Ticker really belongs to the right issuer.

Raw Assets

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Issued Assets without a record on the Asset Registry will not have the same richness in information as registered assets.

You can anyway see a very important piece of information, which is the Asset ID. This 64 hexadecimal characters long string is the unique identifier of any asset, and you should always check with the asset issuer that you received an asset that matches their specified Asset ID. The asset issuer should always publish the ID of any asset they issue, otherwise anyone could cheaply create a bogus asset and defraud you by sending a worthless asset.

Receiving L-BTC and Issued Assets

To receive Liquid Bitcoin or any other Issued Asset, all you need to do is provide a receiving address to the sender.

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A Liquid receiving address is a string of numbers and letters. You can create a receiving address by selecting “Receive” from the main screen.

All addresses in Liquid are, by default, blinded using Confidential Transactions. Blinding is the process by which the amount and type of asset being transferred is cryptographically hidden from everyone except the sending and receiving parties.

Your wallet will generate a new receiving address each time you prompt it for one. While it is possible to reuse old addresses, we strongly advise against this because it lessens your privacy.

Once you can see what your new address is, you’ll need to communicate it to the sender. If you need to send over a distance, a text message or email is an effective way to do it.

If you are physically beside the person who will be sending you Bitcoin, another option is to use the QR code, which the sender can scan to get the receiving address. This is really convenient if the sender is using a mobile wallet.

Once someone has sent a transaction to your Blockstream Green wallet, it should appear in your transaction list page. At first, it will be labelled “unconfirmed”.

Transactions on Liquid are settled with finality after 2 blocks, therefore you can consider your funds to be finally received within 2 or 3 minutes, under normal network conditions.

Sending Transactions

To send a transaction, select “Send” from the main screen.

You will need to get the receiving address from the recipient, and enter it (either by typing or pasting it in, or by scanning the receiver’s QR code).

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Then, you can select the asset you wish to send and input the amount that you want to send , and hit send.

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Your wallet will also automatically calculate a fee for your transaction, which is necessary to have the network accept it and to avoid Denial of Service.

Finally you can review your transaction and send it after confirming your Two-Factor Authentication.

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After you have sent a transaction, it will be settled with finality after 2 blocks, therefore your counterparty will receive the funds within 2 or 3 minutes, under normal network conditions.

Our Multisignature Model

Blockstream Green wallets use a special transaction format different from most other Bitcoin wallets.

Most other storage services in Bitcoin are either “custodial” or “non-custodial without Two-Factor Authentication security”.

Custodial services, such as exchanges, hold your Bitcoin for you. This also means that they can confiscate your coins at will, or if they get hacked, your coins can get stolen. It also usually means KYC identification, and risks of privacy loss.

Other non-custodial wallets do not have those issues, but it also means that if someone steals your mnemonic or gain access to your wallet, they can steal all of your coins. The secrecy of your mnemonic is the only thing protecting your coins with these wallets.

With Blockstream Green, you get the benefits of both types.

This is possible because coins in Blockstream Green wallets have two different spending conditions.

The first way to spend coins is using signatures from 2 different keys to send coins. One is held by the user in the form of the mnemonic, which the service never knows. The other is stored on our server, and we sign your transactions with it after any Two-Factor Authentication you have enabled verifies the transaction.

This means that, unlike custodial solutions, we can never steal your coins, since we don’t know your mnemonic. Even if we get hacked, or taken over by a government entity, or something else catastrophic happens, no one can steal your coins.

On the user side, even if someone steals your mnemonic, they cannot spend your coins unless they can access your Two-Factor Authentication. This is the type of security that other wallets do not offer.

The second way to spend coins becomes available after your two factor recovery period expires. Once this happens, you can spend your coins without our service needing to also sign. This is to ensure that no matter what happens, you can always get your coins back

Redeposits

As explained above, coins in your main Blockstream Green wallet (or a 2of2 simple account) require 2 signatures to be spent: one from you and one from Blockstream Green. In order to protect you from loss of access to your coins should Blockstream Green become unavailable, there is an alternative spend condition which requires only the user’s signature, provided that a certain period of time has passed.

If the service becomes unavailable, you simply wait for the specified period (65535 blocks on Liquid, circa 45 days days, by default), then sign and send the transaction using our open source recovery garecovery.

After the expiry period passes, any limits placed on your spending in Blockstream Green, such as Two-Factor Authentication requirements, cease to be enforceable by the service.

At this point the wallet will prompt you to redeposit the coins by sending them to yourself (If you don’t log in to the wallet during this time, and you have email notifications enabled, the service will email you a reminder as the expiry date gets closer). The confirmation of the redeposit transaction resets the expiry period, thereby re-protecting the coins by once again requiring a Blockstream Green signature to spend them.

Keep in mind that this redeposit transaction is a regular Liquid transaction, and as such is subject to the usual network fees.