Some doubts about Change Addresses

[tryingtomine]

Hey fellow crypto people. Recently I tried to transact btc from blockchain.info wallet to a exchange address,  What blockchain did was sent the requested btc to the exchange address and did another big transaction to a random btc address , but the balance in my blockchain address was showing correct. I panicked to see that and sent all my btc to another safe place with a higher fees as the previous transaction was still not had any confirmation. After that I researched about it and got to know that it was Change address and my btc was safe. My question here is "How to get the private key of that new address (Change address)?" I can not find that new address in my blockchain.info addresses section.

[1713874763]

1713874763

[1713874763]

1713874763

[1713874763]

1713874763

[1713874763]

1713874763

[TryNinja]

Try this:

1. Get your wallet seed (Settings -> Security -> Recovery Phrase);
2. Go to iancoleman's bip39 tool (download the source and run offline if you want to be safer);
3. Enter your seed in the "BIP39 Mnemonic" field;
4. You should see your addresses in the list at the bottom of the page;
4. But you want your change addresses, so change the "External / Internal" field from 0 to 1;

(I saw this method somewhere in the forum but I can't find the original post)

[jackg]

1. Follow TryNinja's advice above.

2. If you want to do this frequently, try changing wallets to something like electrum instead of using a web wallet as they are much less secure than one on your desktop and the change is handled a bit better (in my opinion as blockchain.info has a lot of bugs with it that have been reported - especially with change address generation and spending).

[Xynerise]

You don't need to panic.
Your wallet (blockchain.info) is a HD (hierarchical deterministic) wallet, meaning that it can generate all the private keys (and hence addresses) of your wallet with the 12 (or so) word phrase you were given and told to store securely.
You don't need to know the private key itself as your wallet already takes care of that and you can always generate all your addresses with the seed phrase by importing it into another wallet.
However, if, for whatsoever reason, you wish to see the private key of the address in WIF, then follow the instructions posted by TryNinja above.

[bob123]

Is there a reason you want to get the private key of your change address?
If its just to back your coins up, you just need the seed phrase which you got from blockchain.info when setting up the wallet.
To get the private key you can use https://iancoleman.io/bip39/, like TryNinja mentioned.

But i would suggest you switch over to a wallet which lets you (and only you) have the control over your funds.
You always need to remember that blockchain.info (just a company - has nothing to do with the 'blockchain') has full access to your private keys.
You have to keep in mind that you are relying on blockhain.info (as a company) to access your funds. This envolves trust at a point where you could easily rely on yourself instead of a 3rd party. [Edited for clarity]
Web wallets have a lot of additional attack vectors which 'standard' wallets (desktop-/mobile/hardware) don't have.
So unless there is a good reason for you to use a web wallet, a 'standard' wallet would be the safer option to store your coins.

[HCP]

But i would suggest you switch over to a wallet which lets you (and only you) have the control over your funds.
You always need to remember that blockchain.info (just a company - has nothing to do with the 'blockchain') has full access to your private keys.

Are you sure about that? Because Blockchain.info claim otherwise...

CLIENT SIDE ENCRYPTION MEANS ONLY YOU HAVE ACCESS TO YOUR WALLET

We do not store your bitcoins, we only provide you with the software you need to store them yourself. Your wallet is encrypted on your device with your personal password. Your password acts as your decryption key to both lock and unlock your wallet — your wallet cannot be accessed without it. Because we don’t know or store your password (we can’t even reset it), only you are able to unlock and decrypt your wallet.

They store an encrypted copy of your wallet... but the seed generation, password and encryption/decryption is all handled client side... b.info have no idea what your seed or private keys or password are... That's why they can't reset/restore anything for you unless you have the seed mnemonic (https://support.blockchain.com/hc/en-us/articles/211205343-I-forgot-my-password-What-can-you-do-to-help-)


However, I totally agree that web-wallets really aren't a great solution if you're holding a substantial amount of BTC.

[bob123]

But i would suggest you switch over to a wallet which lets you (and only you) have the control over your funds.
You always need to remember that blockchain.info (just a company - has nothing to do with the 'blockchain') has full access to your private keys.

Are you sure about that? Because Blockchain.info claim otherwise...

CLIENT SIDE ENCRYPTION MEANS ONLY YOU HAVE ACCESS TO YOUR WALLET

We do not store your bitcoins, we only provide you with the software you need to store them yourself. Your wallet is encrypted on your device with your personal password. Your password acts as your decryption key to both lock and unlock your wallet — your wallet cannot be accessed without it. Because we don’t know or store your password (we can’t even reset it), only you are able to unlock and decrypt your wallet.

You are right. I somehow missed that.
Unfortunately its not entire verifiable whether they fully run their open source code.
Cloning the repository and running their code offline seems to be a pretty sweet solution (https://github.com/blockchain/My-Wallet-V3-Frontend).

Probably wouldn't have thought about this without your correction 
This at least eliminates the risk of blockchain.info getting compromised.

[HCP]

Yeah... That is always the risk with "online" stuff... Hard (impossible?) to know if the code in use is actually the code that is shown in GitHub etc...

Much like desktop wallets and using binaries... Unless you run from source or compile yourself, you can never really be 100% sure that the code you're running is actually the same as the source available.

Still, the fact they actually offer an "offline" version is pretty decent... Not sure I'd use it given my perception of their "quality"... But it's a start!

[tryingtomine]

Thank to all of you. I shifted Ledger nano s now.

Your answers cleared all my doubts.