<p>Assuming you have a symmetrically encrypted copy of your private key, where the encryption key was derived from a passphrase, you would be trying to perform a <a href="http://Known-plaintext%20attack" rel="nofollow noreferrer">known-plaintext attack</a>. However, it should not be possible in polynomial time for a proper AES implementation, so I'm afraid you're out of luck.</p>

CC BY-SA 3.0
2017-07-10T21:13:10.090Z
2017-07-10T21:13:10.090Z
arik
<p>I have private key. How can I get passphrase for my bitcoin address.</p>

CC BY-SA 3.0
2017-07-10T21:37:13.400Z
What do you mean by "passphrase for your bitcoin address"? Addresses are not encrypted or password protected. Do you mean you have an encrypted copy of your private key (e.g. in an encrypted backup)? Or do you have a private key and you just want the corresponding address?
Ava Chow
<client>
How to get passphrase from a private key?
Kasaram Bala
# How to get passphrase from a private key?

(Asked by: username_0 on 2017-07-10)

I have private key. How can I get passphrase for my bitcoin address.

**Tags:** client

> **Comments:**
> **username_1**: What do you mean by "passphrase for your bitcoin address"? Addresses are not encrypted or password protected. Do you mean you have an encrypted copy of your private key (e.g. in an encrypted backup)? Or do you have a private key and you just want the corresponding address?  

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## 1 answers

### Answer by username_2 on 2017-07-10. Score: 1

Assuming you have a symmetrically encrypted copy of your private key, where the encryption key was derived from a passphrase, you would be trying to perform a [known-plaintext attack](http://Known-plaintext%20attack). However, it should not be possible in polynomial time for a proper AES implementation, so I'm afraid you're out of luck.


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