Your wallet's security rests on a good random number. Hardware wallets make one for you, but you cannot easily check how. Dice give you a way that you can see. This advanced how-to is part of our guide to advanced setups.
Why do it?
If a device's random number generator were weak or malicious, your phrase might be guessable, and you might never know. Generating randomness with dice means that you do not have to trust the device for this one step.
How many rolls
| Target | Bits | Rolls of a six-sided die |
|---|---|---|
| 12 words | 128 | 50 |
| 24 words | 256 | 99 |
How to do it
- Choose your tool. Use a hardware wallet or air-gapped device that accepts dice rolls, and follow its official guide.
- Prepare. Use a private room, without cameras. Use casino-grade or several ordinary dice.
- Roll. Enter every roll into the device. Do not choose or "fix" a number.
- Let the device finish. It will calculate the checksum word.
- Write down your phrase. Follow the usual steps.
- Test it. See how to test your backup.
What can go wrong
| Risk | Why it matters | What helps |
|---|---|---|
| Biased dice | Reduces randomness | Good dice, and extra rolls |
| Bad rolling | Dice not properly shaken | Roll in a tray or cup |
| Being watched | Rolls are the secret | Privacy |
| Paper notes | Rolls are as sensitive as the phrase | Destroy them |
| Web tools | Your seed could be stolen | Stay offline |
| Skipped rolls | Reduced strength | Use the full count |
Do not use a website
Never type dice rolls into an online tool. Rolls are your secret, and an offline page on a connected computer is still exposed. Use a dedicated offline device.
Verifying the result
Advanced users check the result by repeating the calculation on a second offline tool. Some wallets publish how to do this. If you cannot verify it, you are still trusting the device.
Does this replace everything else?
No. Dice only address randomness. Most losses come from exposed or lost phrases, not bad randomness. See can someone guess my seed phrase?, and keep your focus on backups and scams.