How to fill in your codebook

  1. Print this page.
  2. Fill in every cell. In pen, write one digit, character, or word in each of the 100 cells, scattered with no obvious pattern. For a PIN, use digits 0–9. For a password, use any letter, digit, or symbol. For a seed phrase, use a real BIP-39 word in every cell — your seed words plus decoy words for the rest, so your real words don't stand out. Only real BIP-39 words as decoys; anything else would make your real words obvious.
  3. Look up your secret. For each digit, character, or word of your secret, in order, find a cell holding it and write down its row and column as a two-digit coordinate (row first, then column) — for example, row 3, column 7 → "37". Avoid reusing the same cell twice within one secret if you can; if a digit, character, or word repeats and your codebook only has one copy of it, reusing that coordinate is the only option, but know that it reveals the repetition to deadkey.net.
  4. Type in the coordinates. Go to deadkey.net/create, choose Tin foil hat mode, and type in only the coordinates, in the order they belong.
  5. Hand off the codebook. Give this filled-in codebook to your trusted person, in person. It should never be photographed, scanned, or typed into any computer. If it protects a seed phrase, only hand it to someone you would trust with the funds themselves — whoever ends up holding the words controls the wallet.

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Nothing on this template is generated by deadkey.net — that is the point of Tin foil hat mode. For a PIN or password, you can instead choose Assisted mode and let deadkey.net generate and print a random codebook for you automatically. For a seed phrase there is no Assisted alternative — deadkey.net must never see your seed words, so tin foil hat mode, filled in entirely by hand, is the only option.