Why?

It is almost impossible to produce private, provably secure randomness with an electronic device. A seed phrase produced out of unsound randomness is insecure, and a flaw in the random number generation, either intentional or accidental, can take years to discover. By generating the seed phrase by hand, we eliminate any doubts about its security.

Components

Steps Overview

1. Generate a random binary sequence using the tiles.
2. Convert the binary sequence into seed words using the wordlist.
3. Find the last word while entering the seed phrase into a wallet by trying the 16 possible values for it.

Doing This Well

• Complete this activity in a private space.
• Be careful to avoid pronouncing results or words out loud.
• Keep cameras and prying eyes away.

Generating the Random Binary Sequence

Tiles are a fast and reliable way to generate randomness if they are well-shuffled. The wash shuffle is similar to how children shuffle, i.e. by spreading the cards with both hands and mixing them arbitrarily. This is considered one of the most efficient ways to shuffle, and will ensure the security of the seed phrase. Note that this way of shuffling works best on a fabric surface.

1. Wash-shuffle the tiles thoroughly.
2. Pick up a tile randomly.
3. In the table below, find the binary value corresponding to the character on the tile.
4. Copy this value into the "Binary Sequence" section of the worksheet. Boxes color doesn't matter for this step.
5. Go back to step 1 and keep filling the 11 boxes of each line until the sequence is complete, except for the 4 final boxes marked with "?". Note that for the last tile, only the first 3 binary characters need to be copied.

Converting the Binary Sequence into Seed Words

1. Take the wordlist.
2. Convert each row of the binary sequence into its corresponding seed word, and write these words in the corresponding rows of the "Seed Phrase" section.
3. For the last word, look for the section of the wordlist that has its 16 words starting with the same sequence as the last binary row.
4. Take the wallet that will use the seed phrase.
5. On the wallet, initialize the recovery process and enter the first 11 seed words.
6. Then, try each of the 16 possible words starting with the right binary sequence. Only one will be valid - this is the 12th word.
7. Write down the 12th word on the worksheet.

Storing the Seed Phrase

Cut and store the "Seed Phrase" section in a secure location; If required this can function as a backup to restore the wallet. It is advised to keep this piece of paper into a protecting container, such as a stainless steel pill bottle.

Please note that you risk loosing your funds if the seed phrase is lost or stolen. For a safer and more resilient backup strategy, see the guide Split a Seed Phrase (2-of-3).

The "Binary Sequence" is no longer needed and must be disposed of securely, as it can also be used to take control of the wallet. The recommended way of doing so is to cut and burn that part completely.