Dump pvt key: Bitcoin Core QT

[Almeida]

So I followed all the procedures to dump the pvt keys of some addresses, since I don't want to keep them in my computer. I followed all the instructions here:

https://github.com/OmniLayer/omniwallet/wiki/Exporting-a-private-key-from-Bitcoin-QT-Bitcoin-core-and-Importing-to-Omniwallet.org

and I do have a passphrase and I did type it there correctly.

Oddly, the pvt keys displayed do not start with 5. I suspect this is because they are encrypted, but shouldn't be enough to give the passphrase in order to display them?

Some more info: when I first tried to unlock them with the walletpassphrase command, it was showing error of "syntax". I retyped it several times, correctly every time, until it gave me another response: "null". Then I proceeded to dump the pvt key and I got these pvt keys without the "5" in front of them. What exactly went wrong? Is this "null" normal?

cheers

[1714003204]

1714003204

[mocacinno]

So I followed all the procedures to dump the pvt keys of some addresses, since I don't want to keep them in my computer. I followed all the instructions here:

https://github.com/OmniLayer/omniwallet/wiki/Exporting-a-private-key-from-Bitcoin-QT-Bitcoin-core-and-Importing-to-Omniwallet.org

and I do have a passphrase and I did type it there correctly.

Oddly, the pvt keys displayed do not start with 5. I suspect this is because they are encrypted, but shouldn't be enough to give the passphrase in order to display them?

Some more info: when I first tried to unlock them with the walletpassphrase command, it was showing error of "syntax". I retyped it several times, correctly every time, until it gave me another response: "null". Then I proceeded to dump the pvt key and I got these pvt keys without the "5" in front of them. What exactly went wrong? Is this "null" normal?

cheers

Wait... You're going to export a private key from an encrypted desktop wallet to import in an online wallet because of security??? Sounds like a bad idear to me, it actually sounds like you *should* do the opposite if you want security: stay away from online wallets and use encrypted desktop wallets on a clean pc.

A private key starting with a 5 is shown in Wallet import format. I think dumpprivkey shows the private key in WIF Compressed format. These private keys can start with a K or an L.

Just as extra info, these are the private key formats i currently know:

WIF : 51 characters , always starts with 5
WIF Compressed : 52 characters, starts with a K or L
Hexadecimal Format: 64 characters
Base64: 44 characters

[Almeida]

Wait... You're going to export a private key from an encrypted desktop wallet to import in an online wallet because of security??? Sounds like a bad idear to me, it actually sounds like you *should* do the opposite if you want security: stay away from online wallets and use encrypted desktop wallets on a clean pc.

Oh no, I wont do that!! Why you reached such conclusion? :D

A private key starting with a 5 is shown in Wallet import format. I think dumpprivkey shows the private key in WIF Compressed format. These private keys can start with a K or an L.

Just as extra info, these are the private key formats i currently know:

WIF : 51 characters , always starts with 5
WIF Compressed : 52 characters, starts with a K or L
Hexadecimal Format: 64 characters
Base64: 44 characters

Oh, ok, that makes sense! My wallets are shown in WIF compressed, I was worried bcz all the guides I found online said I should see the WIF with a 5 in front.

That being said, is it possible to continue to send funds to the public keys associated with the pvt keys in WIF compresssed format? I ask that because all the paper wallet generators I say so far they yields a pvt key in WIF uncompressed format, starting with a 5.

So, if I uninstall Core QT from my computer and store these pvt keys in paper (like a plain paper wallet), plus a backup of the wallet in a pen drive, can I recover the funds from any of those sources? Both the backup or the "paper"?

[mocacinno]

Oh no, I wont do that!! Why you reached such conclusion? :D

Because you were using this tutorial: https://github.com/OmniLayer/omniwallet/wiki/Exporting-a-private-key-from-Bitcoin-QT-Bitcoin-core-and-Importing-to-Omniwallet.org
But as long as you only followed the first part, there shouldn't be any problems (actually, there are no problems anyways, bitcoin is about freedom, i just try to give a warning when people are doing something i personally wouldn't do )

Oh, ok, that makes sense! My wallets are shown in WIF compressed, I was worried bcz all the guides I found online said I should see the WIF with a 5 in front.

That being said, is it possible to continue to send funds to the public keys associated with the pvt keys in WIF compresssed format? I ask that because all the paper wallet generators I say so far they yields a pvt key in WIF uncompressed format, starting with a 5.

So, if I uninstall Core QT from my computer and store these pvt keys in paper (like a plain paper wallet), plus a backup of the wallet in a pen drive, can I recover the funds from any of those sources? Both the backup or the "paper"?

You could send funds to the address, the address is a hash of your public key...
Private Key =(hash)=> Publick Key =(different hash)=> Address

It should be possible to reconstruct your public key in WIF format beginning with a WIF compressed key. If you're uncertain, you can always download the sourcecode of https://www.bitaddress.org/, disconnect your pc from the internet, open the sourcecode, go to the "wallet details"-tab and enter your WIF compressed key, the website should be able to re-create your WIF key

BTW: you do realise the private key of your wallet has been on a pc that was connected to the internet? The safest paper wallets are paper wallets generated on an offline machine
Also, as soon as you spend outputs once, you have broadcasted your public key, so it's less safe . That's why it's usually recommended to discard a paper wallet after it's been swept once... Because you're exporting your pk from core, there is a possibility it was already used to sign scripts to spend unspent outputs, hence it's possible the private key for that public key is already out there (doesn't have to be the case, but i'd personally double check if i was going to collect a lot of outputs on that paper wallet)

[Almeida]

Because you were using this tutorial: https://github.com/OmniLayer/omniwallet/wiki/Exporting-a-private-key-from-Bitcoin-QT-Bitcoin-core-and-Importing-to-Omniwallet.org
But as long as you only followed the first part, there shouldn't be any problems (actually, there are no problems anyways, bitcoin is about freedom, i just try to give a warning when people are doing something i personally wouldn't do )

Oh, you're right! And yes, I was just following the first part, no online wallets!!

You could send funds to the address, the address is a hash of your public key...
Private Key =(hash)=> Publick Key =(different hash)=> Address

It should be possible to reconstruct your public key in WIF format beginning with a WIF compressed key. If you're uncertain, you can always download the sourcecode of https://www.bitaddress.org/, disconnect your pc from the internet, open the sourcecode, go to the "wallet details"-tab and enter your WIF compressed key, the website should be able to re-create your WIF key

So, is it always better to store the uncompressed? Or the compressed can also be imported in most hardware wallets?

BTW: you do realise the private key of your wallet has been on a pc that was connected to the internet? The safest paper wallets are paper wallets generated on an offline machine

Holly F... you are scaring me. But yeah, fair enough. I just figured that I could erase everything for now in my PC until I have the need to send the bitcoins, at least diminishing the risk in leaking my pvt key while using the computer meanwhile. But thinking again, it doesn't make much sense, it is just that I'm also scared of sending it to a pure paper wallet and loosing it when trying to import such wallet to bitcoin core and the like. I read somewhere this can happen.

Also, as soon as you spend outputs once, you have broadcasted your public key, so it's less safe . That's why it's usually recommended to discard a paper wallet after it's been swept once...

I don't get this part. Isn't my public address already publicly displayed when I send my funds from a online wallet to this paper wallet anyways? How can my public key receive funds without being displayed in the chain?

Because you're exporting your pk from core, there is a possibility it was already used to sign scripts to spend unspent outputs, hence it's possible the private key for that public key is already out there (doesn't have to be the case, but i'd personally double check if i was going to collect a lot of outputs on that paper wallet)

So far so good, as of now. But you are making me sweat!

Thanks for the replies!

[ranochigo]

Also, as soon as you spend outputs once, you have broadcasted your public key, so it's less safe . That's why it's usually recommended to discard a paper wallet after it's been swept once...

I don't get this part. Isn't my public address already publicly displayed when I send my funds from a online wallet to this paper wallet anyways? How can my public key receive funds without being displayed in the chain?

When you send your funds from an online wallet to a paper wallet, you give the online wallet a Public Key Hash, not a public key. Public key hash can be derived from a public key and not the other way round. For a long time, users have been using Pay-to-Public-Key-Hash instead of Pay-to-public-key transactions and they only need the public key hash to be known. When a transaction is made to address A, the transaction will contain the public key hash of address A.

However, when a transaction is made, the transaction is basically signed with a private key. The corresponding public key can be used to verify the signature and hence, it is included in the transaction. The risk is that, with a public key, if the transaction is generated insecurely (R value reuse), the bruteforcing of keys can get easier with more transaction. With a public key, ECDSA being cracked in the far future can also affect you.