seedpicker

The Seedpicker guide for creating your own seed phrase

This guide aims to educate the reader in a learning-by-doing fashion. However, it does not make any guarantees or promises, and does not take any responsibility for what anyone does with this material.

What you need

Part 1: Generation of 23 random words

Human beings are really bad at randomness! When randomness is important, you should never rely on something that comes from your brain! Modern computers are slowly getting better at randomness, but it is still difficult to make computerized randomness transparent. In other words, it is hard to convince humans that a random number has been created in a truly random fashion. This is the reason most public lotteries use physical and transparent lotto machines instead of using computerized randomness; It is crucial to convince the audience that the randomness is real and not manipulated in any way.

This guide uses a combination of raffle tickets and a six-sided playing die to create very good natural and transparent randomness.

This is how you do it:

You should now have a sheet of paper with 23 secret words, generated with a very high degree of randomness. Randomness that you yourself have witnessed and controlled. Don’t ever let anybody see what you have written on your Seed Form!

Part 2: Calculating the 24th word

The last word of a 24 word seed is a checkum word, calculated using the other 23 words. Unfortunately, we need to use a computer for this step. Since we need to enter our super secret 23 words into a computer, it must be a super secure computer! It must be offline and we must make sure all the secret data is completely discarded after shutdown. Follow the steps below to achieve this!

Note that the software downloaded here does not need to be trusted! The reason is that the 23 words that we generated in the previous step cannot be changed by any software. However, we do have to make sure that the secret information will not leak to the outside world, or to future users of the same computer.

2a: Prepare hardware and software

seedpicker.net/calculator/last-word.html

This is the SeedPicker last word calculator. Let the page load but DO NOT ENTER ANYTHING IN THE FORM YET!

Tip for advanced users: Open a second tab and navigate to iancoleman.io/bip39 DO NOT ENTER ANYTHING YET! Having this page pre-loaded will later enable you to double-check the validity of the generated seed phrase, right before you shut down the computer.

2b: Disable all communication

The secure computer is now fully configured and the next step is to go completely offline:

2c: Perform the calculation

Go back to FireFox and the SeedPicker last word calculator. Following the instructions on the page, enter your 23 words into the field and press the button.

Use your pen to type the resulting 24th word into the designated cell of the Seed Form.

Shut down the computer as soon as possible.

You have now generated a valid BIP39 seed phrase and the only record of it is the Seed Form. Keep it really secret. You may want to make copies and put in different locations. If you make copies, do it manually. Don’t use a copier, camera or any form of computer.

This guide does not cover how to store your seed phrase securely, so do your research well.

If you intend to use the seed phrase with a hardware wallet, it is recommended to use the passphrase feature (sometimes called the 25th word) and keep the two phrases separated.

Comments or suggestions?

Visit github.com/merland/seedpicker or send an email to seedpicker@megabit.se

Thanks!