DIY Bitcoin Seed Storage

BitCan provides a cost-effective, DIY solution for securing Bitcoin mnemonic seed phrases — striking a balance between fragile paper wallets and heavy-duty metal plates.

Each binary-encoded glyph corresponds to a word from the seed list, allowing for discreet stamping onto common materials.

The design ensures that the medium isn't easily deciphered by unintended observers, such as cleaning staff or intruders.

Basic setup
Seed storage preparation from a repurposed aluminium can. Encoding the existing seed phrase into glyphs using the provided chart. Tracing glyphs using a screwdriver. Removing the sticker from the can. The completed seed plate with engraved glyphs. Final storage, plate rolled up.
Durable setup

The average aluminium can may melt in direct fire. To enhance fire resistance, consider:

  1. Placing it in a fireproof container filled with sand or salt, which theoretically could absorb some of the heat.
    Alternative, heat resistant storage, plate rolled up
  2. Stamping the symbols onto stainless steel dog tags that are chained together.
    Note: stainless steel is more challenging to stamp.
    Stamping on a stainless-steep dog-tag. Dog tags on a chain, in order. Heat resistance.

    As an added bonus, dog tags resemble a personal keepsake, which may deter accidental disposal while reducing the likelihood of deliberate theft.

Encoding Instructions
Sticker Template

Print the template, stick it on az aluminium can, draw your seed phrase on the print, then stamp through the sticker with a screwdriver.

  1. Securely generate your mnemonic seed phrase using a trusted, offline hardware wallet in a private location.
  2. Flatten an aluminium can into a sheet (or use a thin stainless steel dog tag) and then attach the printed template to it - or draw it onto a piece of paper and affix it to the sheet.
  3. Translate the words into glyphs, ensuring each corresponds accurately to the provided list.
  4. Stamp each glyph carefully onto the metal, double-checking for precision and verifying the sequence by reviewing it in reverse.
  5. Use a screwdriver for stamping the glyphs into the metal.
  6. To ensure security and privacy, store the stamped metal in a location that is both secure and discreet.
  7. Print the table below into a PDF and back it up.
Decoding Instructions
  1. First, transcribe all glyphs carefully onto a sheet of paper. This will serve as a more reliable reference than working directly from the plate.
  2. Identify the bottom square of each glyph first, as it provides a stable starting point for the decoding process.
  3. Then, identify the top square of the glyph to refine your search within the identified section of the word list.
  4. Alternatively, you can use binary search to navigate through the word list, since each line in the glyph halves the search area.
  5. Verify the transcribed seed phrase with your wallet to ensure its accuracy and integrity.