<p>This is closely tied to the <a href="/questions/tagged/transaction-malleability" class="post-tag" title="show questions tagged &#39;transaction-malleability&#39;" rel="tag">transaction-malleability</a> bug, which allowed the re-posting of unconfirmed transactions with an altered transaction id. The issue increased the complexity for bookkeeping for services with a high number of transactions. Especially, some people used it to sneak duplicate withdrawals from Mt.Gox.</p>

<p>The change to the transaction ID was made by pushing additional zeros to the signature's front. I think <strong>NTX ID</strong> stands for <em>normalized transaction id</em> which will map all duplicate transactions back to the same representation, even when they were altered by exploiting the transaction malleability.</p>

<p>It is an internal blockchain representation used by Mt.Gox and has nothing to do with the service blockchain.info.</p>

CC BY-SA 3.0
2014-02-17T18:20:31.590Z
2014-02-17T18:29:43.647Z
2014-02-17T18:29:43.647Z
Murch
<p>Normalized transaction id is another name for the normalized transaction hash:</p>

<blockquote>
  <p>A Normalized Transaction Hash is a hash of the serialized transaction with its input scripts blank. This hash cannot be altered through transaction malleability</p>
</blockquote>

<p>See a discussion here:</p>

<p><a href="https://github.com/bitcoin/bitcoin/pull/3656" rel="nofollow">https://github.com/bitcoin/bitcoin/pull/3656</a></p>

CC BY-SA 3.0
2014-02-17T18:23:17.893Z
2014-02-17T18:23:17.893Z
Diego Basch
<p>Mt. Gox have released <a href="https://www.mtgox.com/img/pdf/20140217-Announcement.pdf" rel="nofollow">a statement</a> concerning their recent withdrawal problems.</p>

<blockquote>
  <p>In order to launch the new system, we are going through the following
  steps:</p>
  
  <ul>
  <li>Re-indexing the entire Blockchain (approx. 32 million entries)</li>
  <li>Fully deploying the new <strong>NTX ID</strong></li>
  <li>Implementing a new bitcoin withdrawal queue that needs to be tested</li>
  </ul>
</blockquote>

<p>Is the <code>NTX ID</code> something native to the Blockchain.info API? Does Blockchain.info host it's own separate version of the actual blockchain with additional meta data?</p>

CC BY-SA 3.0
2014-02-17T19:07:31.053Z
The blockchain.info tag should be removed as this question is unrelated to the service. Instead transaction-malleability would be fitting.
Murch
CC BY-SA 3.0
2014-02-17T19:13:47.283Z
related: [What is the normalized transaction hash of a transaction?](http://bitcoin.stackexchange.com/q/22168/5406)
Murch
<transactions><blockchain><mtgox><transaction-malleability>
What is the NTX ID that Mt. Gox refer to in their Feb 17th Statement?
QFDev
# What is the NTX ID that Mt. Gox refer to in their Feb 17th Statement?

(Asked by: username_0 on 2014-02-17)

Mt. Gox have released [a statement](https://www.mtgox.com/img/pdf/20140217-Announcement.pdf) concerning their recent withdrawal problems.

> In order to launch the new system, we are going through the following
> steps:
>
> * Re-indexing the entire Blockchain (approx. 32 million entries)
> * Fully deploying the new **NTX ID**
> * Implementing a new bitcoin withdrawal queue that needs to be tested

Is the `NTX ID` something native to the Blockchain.info API? Does Blockchain.info host it's own separate version of the actual blockchain with additional meta data?

**Tags:** transactions, blockchain, mtgox, transaction-malleability

> **Comments:**
> **username_1**: The blockchain.info tag should be removed as this question is unrelated to the service. Instead transaction-malleability would be fitting.  
> **username_1**: related: [What is the normalized transaction hash of a transaction?](http://bitcoin.stackexchange.com/q/22168/5406)  

---

## 2 answers

### Answer by username_1 on 2014-02-17. Score: 1 | Accepted answer

This is closely tied to the [transaction-malleability](/questions/tagged/transaction-malleability "show questions tagged 'transaction-malleability'") bug, which allowed the re-posting of unconfirmed transactions with an altered transaction id. The issue increased the complexity for bookkeeping for services with a high number of transactions. Especially, some people used it to sneak duplicate withdrawals from Mt.Gox.

The change to the transaction ID was made by pushing additional zeros to the signature's front. I think **NTX ID** stands for *normalized transaction id* which will map all duplicate transactions back to the same representation, even when they were altered by exploiting the transaction malleability.

It is an internal blockchain representation used by Mt.Gox and has nothing to do with the service blockchain.info.


---

### Answer by username_2 on 2014-02-17. Score: 1

Normalized transaction id is another name for the normalized transaction hash:

> A Normalized Transaction Hash is a hash of the serialized transaction with its input scripts blank. This hash cannot be altered through transaction malleability

See a discussion here:

<https://github.com/bitcoin/bitcoin/pull/3656>


---

