<p>I just found the answer from <a href="https://en.bitcoin.it/wiki/Protocol_specification#Signatures" rel="nofollow">https://en.bitcoin.it/wiki/Protocol_specification#Signatures</a>:</p>

<blockquote>
  <p>For ECDSA the secp256k1 curve from <a href="http://www.secg.org/collateral/sec2_final.pdf" rel="nofollow">http://www.secg.org/collateral/sec2_final.pdf</a> is used.</p>
</blockquote>

<p>i.e. the curve is </p>

<blockquote>
  <p>y^2 = x^3 - 7 </p>
</blockquote>

<p>and the prime </p>

<blockquote>
  <p>p = 2^256 - 2^32 - 2^9 - 2^8 - 2^7 - 2^6 - 2^4 - 1. </p>
</blockquote>

<p>See <a href="https://en.bitcoin.it/wiki/Secp256k1" rel="nofollow">here</a> for more information.</p>

CC BY-SA 3.0
2013-04-10T05:25:51.810Z
2013-04-10T06:20:27.637Z
2013-04-10T06:20:27.637Z
h__
<p>Bitcoin used Elliptic Curve Digital Signature Algorithm. (see <a href="https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses">here</a>). I'm wondering what standard is actually used for this Algorithm: which curve? which prime? Can anybody give me a reference? (Wiki gives <a href="http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf">this</a>, is this the standard that the ECDSA in Bitcoin?) Anywhere I can find an update on this?</p>

<p>Edit: A bunch of curves are given in page 87 of <a href="http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf">this</a>. Is bitcoin using one of these?</p>

<transactions><cryptography><signature>
What standard is used for the ECDSA to verify transactions?
h__
# What standard is used for the ECDSA to verify transactions?

(Asked by: username_0 on 2013-04-10)

Bitcoin used Elliptic Curve Digital Signature Algorithm. (see [here](https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses)). I'm wondering what standard is actually used for this Algorithm: which curve? which prime? Can anybody give me a reference? (Wiki gives [this](http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf), is this the standard that the ECDSA in Bitcoin?) Anywhere I can find an update on this?

Edit: A bunch of curves are given in page 87 of [this](http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf). Is bitcoin using one of these?

**Tags:** transactions, cryptography, signature


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## 1 answers

### Answer by username_0 on 2013-04-10. Score: 4

I just found the answer from <https://en.bitcoin.it/wiki/Protocol_specification#Signatures>:

> For ECDSA the secp256k1 curve from <http://www.secg.org/collateral/sec2_final.pdf> is used.

i.e. the curve is

> y^2 = x^3 - 7

and the prime

> p = 2^256 - 2^32 - 2^9 - 2^8 - 2^7 - 2^6 - 2^4 - 1.

See [here](https://en.bitcoin.it/wiki/Secp256k1) for more information.


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