YetiCold or YetiWallet is a great way to store your bitcoin on your own. There is a great video walkthrough about how to do the wallet creation, and the instructions within Yeti guide you through this process pretty clearly. However, after that, you’re instructed to erase your entire machine, and it’s up to you to get your wallet back afterwards! I was a little nervous about doing this, and didn’t want to start sending coins to this wallet until I could be sure I knew how to get the wallet back after wiping the machine. So I decided to test it. I deleted my wallet, and tried recovering it.
This is how to get your wallet back using 3 of your 7 seeds. It also has a bit more explanation about how the 3 of 7 multisig wallet is set up, how wallet files work in Bitcoin Core, and what all the text at the bottom of each seed file is.
Bitcoin core keeps your wallet in a file called Wallet.dat in the hidden .bitcoin folder in your home directory. This wallet file has to be present for you to use your wallet and spend your coins. While it is gone (i.e., after you wipe your machine), you can still receive coins at a previous address generated with the wallet. The blockchain will remember that those coins are there for you. But what happens when you want to regenerate/recover the wallet so you can spend them?
Remember that YetiCold generates your seven seeds, and an additional file called “Descriptor.txt.” Descriptor.txt contains a very long string of letters and numbers that explains how all the seeds fit together so that 3 of the 7 can be used to regernate the wallet. This string from Descriptor.txt is copied at the end of each seed. So that way, each seed carries the instructions about how it fits together with the other seeds. Basically, to recover a wallet, you just load up a seed into YetiCold so it can pull the descriptor out of it. Then, you load up three seeds in succession. It will then rescan for a few minutes, and you’ll then have your wallet back. Here’s how it’s done:
Run YetiCold. This can be accomplished by opening Terminal, and running the following commands to enter the directory where YetiCold is stored, then starting it using Python3 to run initialize.py, specifically with the YetiLevelTwo version:
python3 initialize.py YetiLevelTwo
YetiCold will open. From here, you just need to go to “Recover Wallet.”
You now need to download the blockchain and have your computer validate it. This will take at least overnight (with an SSD), and may take several days (with an HDD). YetiCold will wait around until this is complete. You can do this ahead-of-time so it’s ready without compromising security.
Next, Yeti will ask you to load up a seed (any seed!) so it can pull the descriptor. Just browse for the file (on your CD, or copied onto a device — careful!)
Finally, you’ll have to import any 3 of your seven seeds similarly. Put each CD in and browse to it and it’ll load them up. Each phrase will turn green once it’s validated.
After that, you’ll hit next. It’ll rescan for a few minutes, and then you’ll have your wallet recovered. If your blockchain is synced, it’ll know what your balance is (with all the coins received).