<p>In ECDSA public keys are usually generated from a random private key. The simple answer then would be, that instead of using a random private key, you use the given private key and it should generate the public key. After that, perform the <a href="https://en.bitcoin.it/wiki/Address">steps listed in the Wiki</a> to find out the conventional notation for the public key you can use anywhere.</p>

CC BY-SA 3.0
2011-10-28T21:34:33.310Z
2011-10-28T21:34:33.310Z
ThePiachu
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="https://bitcoin.stackexchange.com/questions/1389/how-are-public-private-keys-in-an-address-created">How are public &amp; private keys in an address created?</a>  </p>
</blockquote>



<p>I am scanning in a private key from a QR code in an app I am writting to handle the import of physical bitcoins.</p>

<p>Given a private key, how can I get the public key so that I can lookup its value on the block explorer?</p>

CC BY-SA 3.0
2014-07-31T21:01:20.880Z
@RobKohr I made a practical example here: http://bitcoin.stackexchange.com/a/29811/1761 I hope this help you.
Felipe
CC BY-SA 3.0
2011-10-28T21:15:10.497Z
Do you want the algorithms? Do you want code in a specific language?
David Schwartz
CC BY-SA 3.0
2011-10-29T21:57:57.440Z
Yep, that question answered it.
RobKohr
<transactions><development><qrcode>
Given a private key, how do you get a public address
RobKohr
# Given a private key, how do you get a public address

(Asked by: username_0 on 2011-10-28)

> **Possible Duplicate:**  
> [How are public & private keys in an address created?](https://bitcoin.stackexchange.com/questions/1389/how-are-public-private-keys-in-an-address-created)

I am scanning in a private key from a QR code in an app I am writting to handle the import of physical bitcoins.

Given a private key, how can I get the public key so that I can lookup its value on the block explorer?

**Tags:** transactions, development, qrcode

> **Comments:**
> **username_2**: Do you want the algorithms? Do you want code in a specific language?  
> **username_0**: Yep, that question answered it.  
> **username_1**: @username_0 I made a practical example here: http://bitcoin.stackexchange.com/a/29811/1761 I hope this help you.  

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## 1 answers

### Answer by username_3 on 2011-10-28. Score: 5 | Accepted answer

In ECDSA public keys are usually generated from a random private key. The simple answer then would be, that instead of using a random private key, you use the given private key and it should generate the public key. After that, perform the [steps listed in the Wiki](https://en.bitcoin.it/wiki/Address) to find out the conventional notation for the public key you can use anywhere.


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