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Seedphrase in Bitcoin Core
236 sats \ 10 comments \ @0xbitcoiner 10 Nov bitcoin_beginners

@optimism reminded me that with Bitcoin Core, you can't actually see your wallet's seedphrase or import a wallet using one. So, my questions are: What's the best way to back up a Bitcoin Core wallet, and is there any tool or trick to get the seedphrase out of it?

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200 sats \ 7 replies \ @optimism 10 Nov
  1. Turn on passphrase encryption (which you should have in the first place)
  2. help backupwallet and follow instructions until you successfully did backupwallet
  3. And then, copy the file to encrypted storage.

So while technically, encrypted backup > cleartext phrase, Bitcoin Core is right in that, I only used the Bitcoin Core wallet once ever since BIP-157 was created, and that was when I needed to recover funds in extreme paranoid mode. I'd still use it for that today, but that is my only use case. But then, realize that I run a private electrs on colo'd, private VPN'd metal, which is not something everyone can actually manage, or even afford, because that's costing me a couple 100k sats a month for rack rent and more in time spent to review every fucking security update.

So if you just have the skills / time / money to run a node, back it up, put it on an encrypted drive, preferably more than 1.

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100 sats \ 6 replies \ @0xbitcoiner OP 10 Nov
So while technically, encrypted backup > cleartext phrase, ...

How do I see the seed phrase from here? Any external tool?

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33 sats \ 5 replies \ @optimism 10 Nov

That's impossible-ish. root = sha512(seed phrase). One-way unless you have a quantum computer that can compute sha512.

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100 sats \ 4 replies \ @0xbitcoiner OP 10 Nov

Can't you even see it even if you know the encryption password?

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33 sats \ 2 replies \ @optimism 10 Nov

If you look at https://iancoleman.io/bip39/, this is what you can recover, everything above, not:

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100 sats \ 1 reply \ @0xbitcoiner OP 10 Nov

So, if I get this right, you can't figure out the seed phrase from the BIP32 root key, but you can move funds from that wallet. Is that correct?

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33 sats \ 0 replies \ @optimism 10 Nov

Correct. BIP-39 is a convenience protocol. And it's been "discouraged for implementation" (because this) which is why it's not in Bitcoin Core.

However, one cannot get rid of BIP-39 even if it's as horrible as cryptographers think it is because after the PBKDF2_SHA512(mnemonic_seed) you cannot reverse it... so it's here to stay no matter what, in lieu of a better standard.

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33 sats \ 0 replies \ @optimism 10 Nov

You can extract the root key, not the seed phrase. See BIP-39 though it's extremely sparse [😭]

  1. oh and it's 2048 sha512 rounds using PBKDF2, so yeah, good luck with that quantum noob shit google ↩

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121 sats \ 1 reply \ @DarthCoin 10 Nov

Usually and recommended is that you do not use a bitcoin node as a wallet, but just as a blocks provider for other wallet apps connected to it.

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0 sats \ 0 replies \ @0xbitcoiner OP 10 Nov

Yeah, that's how I've been running it. I totally forgot you couldn't even do that.

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