What is a Satoshi Test?

A "Satoshi Test" is a verification step sometimes used by cryptocurrency exchanges or services. It involves sending a very small, specific amount of Bitcoin (measured in satoshis) from a Bitcoin address you wish to prove you control. Successfully sending this tiny amount demonstrates that you have access to the private keys for that address. Exchanges may require this for security and compliance, like AML/KYC procedures, ensuring withdrawals go to addresses you verifiably own.

Why Coin Control is vital for Satoshi Tests

To successfully complete a Satoshi Test with your BitBox hardware wallet and the BitBoxApp, the Coin Control feature is essential. Here’s why:

• A Satoshi Test requires you to send funds from a specific UTXO (Unspent Transaction Output – think of it as a particular "piece" of Bitcoin) linked to the address you are verifying.
• The Coin Control feature in your BitBoxApp allows you to manually select that specific UTXO as the input for your transaction.

Without Coin Control enabled, the BitBoxApp might automatically select UTXOs from different addresses, which could cause the Satoshi Test to fail.

Prepare your BitBox for a Satoshi Test

Follow these steps to get ready for a smooth Satoshi Test:

01 Update software & connect wallet 

Ensure you're running the latest version of the BitBoxApp. Outdated software can cause issues. Connect your BitBox02, unlock it, and ensure it's accessible in the app.

02 Confirm sufficient Bitcoin balance

The Bitcoin UTXO associated with the address you need to verify must contain enough Bitcoin to cover:

• The exact small amount required for the Satoshi Test.
• The anticipated Bitcoin network transaction fee (miner fee). If needed, add a small amount of Bitcoin to that address first. You can use the "Buy" feature in the BitBoxApp if necessary.

03 Activate Coin Control

This is crucial. To enable it:

1. Open your BitBoxApp.
2. Navigate to Settings.
3. Go to Advanced settings.
4. Toggle on the Enable coin control option.

04 Review exchange instructions carefully

Your exchange or service will provide specific details for the Satoshi Test. Pay close attention to:

• The exact destination Bitcoin address (usually one of their addresses).
• The precise, small amount of BTC they require you to send. Sending a different amount can cause verification failure.

With these preparations, you're ready to perform the actual Satoshi Test transaction.