Cryptocurrency/ Bitcoin Seed Phrases Cold Storage

To store cryptocurrency seed passwords securely (eg to restore a wallet on Trezor device) one needs to store the 12-24 words in order onto a material that will withstand water, impact and fire damage. Choosing to engrave/ stamp the words onto steel and storing them in a robust outer protective layer is a good way to make sure that your seed passwords will survive most unexpected accidents.

This is a cheap, fast and easy way to construct a robust storage system for your cryptocurrency seed phrase.

1. Steel washers (x 12-25; M5 (5.3mm x 25mm x 1.5mm) - cost ~ 2.50€
2. Bolt (x 1; M5 50mm) - cost ~ 0.50€
3. Nut (x 1; M5) - cost ~ 0.20€
4. Stamping set (5mm type A-Z, 1-9) [optional Dremel] - cost ~ 10.00€
5. Steel hammer
6. Iron surface
7. Iron piping - water pipe (x 1) (25mm/ 1" x 60mm) - cost ~ 2.00€
8. Brass heads (x 2) for iron piping (25mm/ 1" type) - cost ~ 3.00€

1. Place one washer on a solid metal surface.
2. Line up the letter you wish to stamp/ engrave.
3. Hit solidly with metal hammer (you may wish to do a few test hits to get your letter placement correct). Using a dremel you can also engrave the letters but this takes more skill to get comparable results.
4. Check the letter has been indelibly impressed onto the washer.
5. Leaving enough space between letters stamp the next letter next to the first. Use the hole and the edge of the washer as a guide. It works best if the letters are stamped radially.
6. Four letters are (usually) sufficient to identify the seed word.
7. Stamp the sequence number of the word.

1. Fit the washers onto the bolt in sequence (the washers are numbered in case they get mixed up).
2. Screw on the nut securely on the bolt so that the washers do not move.
3. Screw the brass head onto one side of the iron piping, securing with a spanner if necessary.
4. Place the stack of washers into the copper piping.
5. Screw the other brass head onto the open end of the iron piping.