An experience trying to setup a simple cold wallet
609 sats \ 7 comments \ @ricalamino 26 Oct 2022 bitcoin
Hi eveybody,
I will describe here how I made a "cold wallet". I would be very happy with suggestions and feedbacks about anything wrong (insecure) in my setup.
First I flashed tails in a USB drive, using the downloaded file from https://tails.boum.org/ . After downloading the file I checked the checksum provided by them to certify the downloaded file was legitime.
After flashing, I booted my laptop with the USB with Tails. After opening Tails, I did not connect to the Wifi, so I opened Electrum software. Then, I created a new wallet and Electrum showed me the 12 word seed which I wrote in a piece of paper far from any camera. After creating the wallet I opened the Xpub key and imported that as a watch-only wallet in the Blue Wallet android app. Then I just turned off Tails and my laptop...
I bought a metal plate in which I engraved the seed as described in their manual... It is a coded BIP39 transforming the words in numbers based on the complete list.
Now I burned the paper so the seed is only in my head and the metal plate. The paper was never accessible to anyone or in front of any camera.
I put the metal plate in a secret place where only my wife knows, but she doesn't know how to decodify that yet... In case the metal plate is compromised somehow (for instance: someone discovers the place where it is hidden, or suspect anyone has seen that), which I think is very unlikely, I plan to move the BTC from that cold to another one...
Soon I plan to buy a Coldcard, but that is what I have now.....
Grateful for any comments...
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544 sats \ 1 reply \ @pillar 26 Oct 2022
Solid.
I would advice:
  • Send a small amount of BTC to your wallet and send it out again safely using your Tails offline to sign a PSBT. That way, you gain confidence for when the time comes to move your stash.
  • Consider making additional copies of your seed phrase. Having only one copy makes it very easy to protect from adversaries, but it also makes it very easy to lock yourself out by mistake.
  • More advanced, but would make a perfect setup: run your own node and point your watch-only wallet to it. That way, nobody else will know what addresses are you looking into, or that you are looking at any as a matter of fact.
I'm sure the community will bring even more ideas, but be proud. You're already on the right track.
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244 sats \ 0 replies \ @ricalamino OP 26 Oct 2022 freebie
Thank you!
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244 sats \ 0 replies \ @SatoshiNakanodo 26 Oct 2022 freebie
This is excellent. Thanks for sharing your steps. One suggestion… as an alternative to the metal plate (which isn’t as indestructible as they claim, especially in a bad fire) I’d recommend stamping your seed words into stainless steel washers (number them so you know what order they go in) then screw them together using a hex bolt. It’s cheaper and virtually indestructible...
TUTORIAL:
PARTS LIST: M8 x 24 x 2.0mm washers: https://amzn.to/3xXLk9i M8-1.25 x 35mm hex bolts: https://amzn.to/3zxvcfp M8-1.25 hex nuts: https://amzn.to/3iAlUZb Metal Stamps Kit: https://amzn.to/3BnG94I (if you already have a hammer you can just buy the stamps: https://a.co/d/ckENJgf) Stamping Jig: https://www.cryptocloaks.com/product/blockmitjig (optional but helpful)
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100 sats \ 0 replies \ @criptopanas 27 Oct 2022 freebie
I think its a great set up, thanks very much for sharing it. Just in case you want to make a metal copy (water & fire resistant) here is a cheap and easy way to do it (in spanish, but you'll get the idea) https://estudiobitcoin.com/fabrica-tu-billetera-fria-con-arandelas/
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40 sats \ 2 replies \ @sandbeach123 27 Oct 2022
Did you erase the wallet on tails or used the persistent volume to store the wallet? The former would be better. Anyway great setup. I would try to test seed recovery on other software (using a dummy seed of course). I know electrum seed formats are kind of special, and only some wallets accept those seeds (I know blue wallet does). Just to have that as an option and to make sure. The rest is good. Well done.
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341 sats \ 1 reply \ @ricalamino OP 27 Oct 2022 freebie
Thank you. I did not use persistent data in Tails, so I hope it has erased the wallet I created. I simply turned off Tails... The next time I used Tails, there was no data.
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20 sats \ 0 replies \ @sandbeach123 27 Oct 2022
Perfect!
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