<p>Sipa is the alias of Pieter Wuille, a Bitcoin Core developer. It just happens that he had a feature branch for the rpc command <code>importprivkey</code>, and people just referred to it as the "sipa" format. It's just something that has hung around in vanitygen and a few places on the Bitcointalk forum, it's not in common use anywhere else. The format being talked about is just base58check encoding with a version prefix differentiating compressed and uncompressed point usage. </p>

<p>This format is today most commonly known as WIF (Wallet Import Format), and also the format used in the MultiBit classic export.</p>

CC BY-SA 3.0
2015-04-24T14:06:25.143Z
You may want to more directly clarify that WIF, "sipa", and MultiBit Classic key export format are all the same (with WIF being the most common name).
Christopher Gurnee
CC BY-SA 3.0
2015-04-24T08:16:27.260Z
2015-04-25T18:03:07.070Z
2015-04-25T18:03:07.070Z
Claris
<p><a href="https://github.com/samr7/vanitygen" rel="nofollow">Vanitygen</a> refers to "Sipa" format <a href="https://github.com/samr7/vanitygen/blob/master/README#L49" rel="nofollow">here</a>:</p>

<blockquote>
  <p>Currently, it is difficult to import the private key into bitcoin.<br>
  <strong>Sipa's</strong> showwallet branch has a new command called "importprivkey" that 
  accepts the base-58 encoded private key.  Vanitygen has been tested to 
  work with that version of bitcoin.</p>
</blockquote>

<p>I remember this term being thrown around when I was relatively new to Bitcoin, probably around the same time as the Vanitygen quote was made. There's a conflicting references to <em>sipa</em> format, it seems, for example, <a href="https://multibit.org/en/help/v0.5/help_importASingleKey.html" rel="nofollow" title="Multibit">Multibit</a> uses <em>Sipa</em> in place of <em>WIF</em>, whereas the aforementioned quote makes no sense in that context. <a href="https://bitcointalk.org/index.php?topic=515449.msg5694715#msg5694715" rel="nofollow">BitcoinTalk seems to suggest Sipa = Base58 WIF</a></p>

<p><em>What, exactly, does the term <code>Sipa</code> refer to?</em> (<strong>EDIT:</strong> And where did the term come from?)</p>

CC BY-SA 3.0
2015-04-24T07:30:31.033Z
Pretty sure it refers to this guy: https://github.com/sipa http://bitcoin.stackexchange.com/users/208/pieter-wuille As for why some people call WIF SIPA format, I don't know.
Nick ODell
CC BY-SA 3.0
2015-04-24T09:05:14.473Z
I believe it refers to me, yes :)
Pieter Wuille
CC BY-SA 3.0
2015-04-24T14:39:08.223Z
@PieterWuille: But you still haven't given us your definition :)
Meni Rosenfeld
<history><terminology>
"Sipa" definition? (old terminology, circa 2011-12)
Wizard Of Ozzie
# "Sipa" definition? (old terminology, circa 2011-12)

(Asked by: username_0 on 2015-04-24)

[Vanitygen](https://github.com/samr7/vanitygen) refers to "Sipa" format [here](https://github.com/samr7/vanitygen/blob/master/README#L49):

> Currently, it is difficult to import the private key into bitcoin.  
> **Sipa's** showwallet branch has a new command called "importprivkey" that
> accepts the base-58 encoded private key. Vanitygen has been tested to
> work with that version of bitcoin.

I remember this term being thrown around when I was relatively new to Bitcoin, probably around the same time as the Vanitygen quote was made. There's a conflicting references to *sipa* format, it seems, for example, [Multibit](https://multibit.org/en/help/v0.5/help_importASingleKey.html "Multibit") uses *Sipa* in place of *WIF*, whereas the aforementioned quote makes no sense in that context. [BitcoinTalk seems to suggest Sipa = Base58 WIF](https://bitcointalk.org/index.php?topic=515449.msg5694715#msg5694715)

*What, exactly, does the term `Sipa` refer to?* (**EDIT:** And where did the term come from?)

**Tags:** history, terminology

> **Comments:**
> **username_1**: Pretty sure it refers to this guy: https://github.com/sipa http://bitcoin.stackexchange.com/users/208/username_2-username_2 As for why some people call WIF SIPA format, I don't know.  
> **username_2**: I believe it refers to me, yes :)  
> **username_3**: @username_2: But you still haven't given us your definition :)  

---

## 1 answers

### Answer by username_4 on 2015-04-24. Score: 5 | Accepted answer

Sipa is the alias of username_2 username_2, a Bitcoin Core developer. It just happens that he had a feature branch for the rpc command `importprivkey`, and people just referred to it as the "sipa" format. It's just something that has hung around in vanitygen and a few places on the Bitcointalk forum, it's not in common use anywhere else. The format being talked about is just base58check encoding with a version prefix differentiating compressed and uncompressed point usage.

This format is today most commonly known as WIF (Wallet Import Format), and also the format used in the MultiBit classic export.

> **Comments:**
> **username_5**: You may want to more directly clarify that WIF, "sipa", and MultiBit Classic key export format are all the same (with WIF being the most common name).  

---

