Dice Roll Method (optional)

The Coldcard uses a random number generator for creating your Bitcoin backup. You can avoid using this if you are wary that it might be compromised or if you wish to input your own source of entropy by rolling a six-sided dice.

Roll your dice 100 times in order to achieve 256 bits of entropy.

Before we attempt the dice rolls in their entirety, we will make sure that the Coldcard isn't duping us into believing that the entropy that we provided is legitimate and they are somehow providing us with a random-looking number that isn't actually random.

Verifying the Dice Roll math

Steps for generating the backup:

1. Using a pen and paper, note down the results of 6 dice rolls

2. In the main menu, select 'Import Existing'

3. Select 'Dice Rolls'

4. Using the Coldcard's keypad, enter the results you obtained by pressing on the corresponding numbers (1 to 6)

5. The Coldcard will produce 24 words, write them down

Steps for verifying that the backup generation is legitimate:

1. Open the Terminal or Shell of your computer to input a command line

2. Enter one of the the following commands :

echo -n 123456 | sha256sum

echo -n 123456 | openssl sha256

Replace '123456' by the dice roll numbers you obtained

Verify that the hash value output matches that on the Coldcard device screen.

Now we want to verify that the hash value really generates the same 24 words.

1. Save the script found here: https://coldcardwallet.com/docs/rolls.py
2. In your Terminal, change the directory to where the above file is saved

3. Run the following command, using the same dice rolls used for your test by replacing the '123456':

echo 123456 | python3 rolls.py

Verify that the 24 words output in your Terminal matches those on your Coldcard!

If they match, then you are good to go with the complete dice roll process.

Doing the actual Dice Roll

Steps for generating the backup:

1. Using a pen and paper, note down the results of 100 dice rolls

2. In the main menu, select 'Import Existing'

3. Select 'Dice Rolls'

4. Using the Coldcard's keypad, enter the results you obtained by pressing on the corresponding numbers (1 to 6)

5. The Coldcard will produce 24 words, write them down

You now have your 24 word backup generated using your own source of entropy!