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.
There are two ways of generating the seed phrase. One that uses a a lookup table and one that uses a webpage. If you opt for the Lookup Table-version you’ll also need:
Human beings are really bad at randomness! When randomness is important, you should never rely on something that comes from a human brain! Modern computers are getting better at creating randomness, but it is still difficult to make computerized randomness in a way that is transparent to us humans. 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.
You can create the seed phrase manually using a lookup table in one of two ways. The Lookup Table or The Dice page.
This method 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:
Use the scissors to cut out the 342 raffle tickets and put them in the bag (or box). Make sure you don’t lose any of them. Mix them around thoroughly!
Use the seed form, the raffle tickets, and the 6-sided die to pick the first 23 words. Read the instructions on the Seed Form carefully, and make sure to follow them all.
When finished, you should have a sheet of paper with 23 secret words, generated with a very high degree of randomness. Randomness that you yourself have witnessed. Don’t ever let anybody see what you have written on your Seed Form!
This method is an automated version of the lookup table that uses one die and the Dice Rolling page that has the lookup table built-in. If you don’t want to bother with cutting raffle tickets this method is for you. The downside is that there’s a lot of dice rolling. If you’re interested in the math behind this method see the last paragraph in this section.
This is how you do it:
This bears repeating: Don’t ever let anybody see your seed phrase!
If you’re not interested in the math behind this metod you can go to Part 2.
The BIP39 dictionary consists of 2048 words. 2048 can be represented in binary with 11 bits. 11^2 = 2048. If you roll a die, treat 1-3 as a 0, 4-6 as a 1 and repeat this eleven times then we get a binary number that corresponds to a word in the word list.
Instead of using a die you could use a coin and use heads and tails to generate your 11 bits.
The last word of a 24 word seed is a checksum word, calculated using the other 23 words as input. 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!
Open up the computer and remove the hard drive. This step is to convince you that nothing will be saved to the hard drive. If you feel certain that this will not happen, you can skip this step.
Remove any removable media from the computer.
Boot up Ubuntu and run it in Live mode (“Try Ubuntu before installing”).
Make sure you have a working Internet connection, wired or wireless (Click the small triangle on the top right of the Ubuntu desktop).
Open Firefox and type in the following address:
This is the SeedPicker last word calculator. Let the page load but DO NOT ENTER ANYTHING IN THE FORM AT THIS POINT!
Tip for advanced users: Open a second tab and navigate to
iancoleman.io/bip39, but DO NOT ENTER ANYTHING AT THIS POINT!
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
Note that the code on the web page(s) downloaded in the previous step does not need to be trusted! Why? Because the 23 words that we created and wrote on paper 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._ This is achieved by disabling all communication and by shutting the computer off when we are done. This is covered below.
The secure computer is now fully configured and the next step is to go completely offline:
Pull any network cable.
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. Make sure it is completely turned off.
You have now generated a valid BIP39 seed phrase and the only existing record of it is the Seed Form. Keep it really secret. You may want to make copies and put in different locations. If you create 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.
Visit github.com/merland/seedpicker or send an email to email@example.com