<p>No, not all passphrases are used to generate the private keys for a wallet. Only specifically brain wallets do that.</p>
<p>Passphrases in actual wallet software like Bitcoin Core and Electrum are used to encrypt the wallet. The private keys are still randomly and securely generated. Your passphrase is only used as an encryption key so that the private keys are stored encrypted on disk.</p>
<p>It is safe and recommended that you encrypt your wallet with a passphrase. If you choose to not encrypt your wallet, then the private keys will be stored unencrypted on disk and any person or malware with access to your computer can steal your private keys and thus your Bitcoin.</p>

CC BY-SA 4.0
2020-08-08T18:21:10.193Z
Thank you a lot Andrew, but I'm a bit confused. How is a private key generated if it doesn't use a passphrase as a seed? Is there any article on this subject you would recommend?
ddavi031
CC BY-SA 4.0
2020-08-08T19:22:04.083Z
@ddavi031 Computers can generate random numbers. See https://en.wikipedia.org/wiki/Random_number_generation
Pieter Wuille
CC BY-SA 4.0
2020-08-08T19:34:06.990Z
Thanks, I'm familiar with that, but I was wondering which algorithms BitcoinCore is using specifically to generate a private key? I can ask this as a new question if you think that is more appropriate and I'm off topic here.
ddavi031
CC BY-SA 4.0
2020-08-08T19:48:06.407Z
I was trying to address your confusion. Private keys are generated randomly; there is no seed or passphrase involved. If you want to know how Bitcoin Core exactly generates randomness, that would be a different question.
Pieter Wuille
CC BY-SA 4.0
2020-08-08T18:12:55.620Z
2020-08-08T18:12:55.620Z
Ava Chow
<p>When I want to create a wallet with <code>BitcoinCore</code> by going <code>File</code>-&gt;<code>Create wallet</code>, it asks me to choose a <code>passphrase</code> for it. Over the mouths exploring Bitcoin I learned that it is very unsafe to use custom passwords since they can be easily cracked (if I'm not mistaken, this type of wallet is called <code>Brain wallets</code>). I'm assuming that the passphrase will be used as a seed for a random generator in order to create private key for that wallet, and all this seems pretty unsafe to me. <br> Also I noticed that there is a checkbox saying <code>Encrypt wallet</code>. Does this mean if I don't make this check, my wallet will be unencrypted and therefore unsafe?</p>

<bitcoin-core><wallet>
How safe is BitcoinCore since it is using owner's passphrase?
ddavi031
# How safe is BitcoinCore since it is using owner's passphrase?

(Asked by: username_0 on 2020-08-08)

When I want to create a wallet with `BitcoinCore` by going `File`->`Create wallet`, it asks me to choose a `passphrase` for it. Over the mouths exploring Bitcoin I learned that it is very unsafe to use custom passwords since they can be easily cracked (if I'm not mistaken, this type of wallet is called `Brain wallets`). I'm assuming that the passphrase will be used as a seed for a random generator in order to create private key for that wallet, and all this seems pretty unsafe to me.   
 Also I noticed that there is a checkbox saying `Encrypt wallet`. Does this mean if I don't make this check, my wallet will be unencrypted and therefore unsafe?

**Tags:** bitcoin-core, wallet


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## 1 answers

### Answer by username_1 on 2020-08-08. Score: 3 | Accepted answer

No, not all passphrases are used to generate the private keys for a wallet. Only specifically brain wallets do that.

Passphrases in actual wallet software like Bitcoin Core and Electrum are used to encrypt the wallet. The private keys are still randomly and securely generated. Your passphrase is only used as an encryption key so that the private keys are stored encrypted on disk.

It is safe and recommended that you encrypt your wallet with a passphrase. If you choose to not encrypt your wallet, then the private keys will be stored unencrypted on disk and any person or malware with access to your computer can steal your private keys and thus your Bitcoin.

> **Comments:**
> **username_0**: Thank you a lot Andrew, but I'm a bit confused. How is a private key generated if it doesn't use a passphrase as a seed? Is there any article on this subject you would recommend?  
> **username_2**: @username_0 Computers can generate random numbers. See https://en.wikipedia.org/wiki/Random_number_generation  
> **username_0**: Thanks, I'm familiar with that, but I was wondering which algorithms BitcoinCore is using specifically to generate a private key? I can ask this as a new question if you think that is more appropriate and I'm off topic here.  
> **username_2**: I was trying to address your confusion. Private keys are generated randomly; there is no seed or passphrase involved. If you want to know how Bitcoin Core exactly generates randomness, that would be a different question.  

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