ICE BATH: Mix to a Cold Postmix
Foundation announced that soon Passport users will be able to mix with whirlpool direct to cold storage postmix account.
Is this already possible you may be wondering? The answer is absolutely yes. Lets walk through a step by step using either samourai or sparrow wallets. With both, we will create an offline wallet, and copy the whirlpool postmix zpub and derivation path (m/84'/0'/2147483646') into a sparrow watch only wallet so that we can utilize sparrow's mix to feature. After we are done with the offline wallet we will make sure we save the seed and passphrase, and securely erase the wallet from the device. It should also be noted that you can roll your own seed in place of letting the wallets create one for you, in this case enter your 12 words intead of generating a new wallet with either software. Please only do this if you have a solid understanding of derivation pathes and how to restore wallets.
It wouldn't be a bad idea to get some testnet bitcoin and run through the setup with some test transactions on testnet.
Samourai WalletSamourai Docs
First things first you need to have a fresh install of samourai ready to generate a new wallet. You can go about this several different ways, make sure you have your backup and securely erase a current samourai wallet, use Insular to create a work profile and install samourai there, or create another userprofile and install there. Once you've installed samourai, open up the app and follow along with the images below
Use my dojo if you don't have your own and don't feel like using samourai's
After connecting to tor and Dojo, throw the phone into airplane mode. Now you're ready to generate the wallet. Click Create a new wallet, enter a stong passphrase, I like to use 3 words, then enter a pin code for the samourai wallet. Write down the 12 word seed and passphrase and store them in a safe place, we are going to get back to them later. Now that you're though the setup it's time to reveal that post mix zpub.
Now its time to get sparrow opened up on our watch only device, click file and new wallet and give it a name. If you don't run your own node or electrum server, connect to this community Fulcrum Server or feel free to use mine.
Now that you've scanned the ZPUB and entered the derivation path (m/84'/0'/2147483646') it's time to securely erase the wallet from your phone.
Lets get started with sparrow. Disconnect your computer from the internet, open up sparrow and toggle the server switch at the bottom right corner off. We don't want to connect to internet right now.
Now go to file menu, new wallet and give it a name. Once you've named it, select new or imported software wallet.
Once you've generated your seed and passphrase, click create keystore and then import keystore, you will have to re-enter the passphrase to continue.
Now we will add the whirlpool accounts in order to get the post mix xpub.
Now we are going to create another new wallet (our ice bath wallet), so click file, new wallet, name it and select xpub/watch only wallet. Then copy and paste the derivation path and XPUB/ZPUB into the watch only wallet, you can use the default 00000000 for the master finger print.
Once you click apply it's safe to go and delete the software wallet you created by selecting File -> Delete Wallet and connect sparrow to a server. If you don't run your own node or electrum server, connect to this community Fulcrum Server or feel free to use mine.
Now simply use sparrows mix-to feature to tuck your sats away . You can also follow Diverter's guide here to skip over using sparrow as a watch only wallet as well. Stamp the seed into metal with ronin steel, or some washers and a letter/number stamp kit. Safely and easily restore the wallet into Samourai or sparrow in the future to keep remixing for free and to utilize post mix spending tools. Like I said at the start, it wouldn't be a bad idea to get some testnet bitcoin and run through the setup with some test transactions on testnet. Playing with testnet is fun and educational. See you in the Ice Bath, cheers.