<p>That's a transaction generated by <a href="http://p2pool.info/" rel="nofollow">p2pool</a>. You assumed correctly in that it is designed to store data, it's used to store some metadata about the current state of the pool. In the future it would probably be better to use <code>OP_DROP</code>, as the output is provably unspendable and is able to be pruned from the mempool and blockchain.</p>

CC BY-SA 3.0
2013-12-09T00:08:03.693Z
2013-12-09T00:08:03.693Z
Anonymous
<p>I found out that some transactions have strange <code>scriptPubKey</code> in their outs. They only contain a hash and nothing more. An example can be seen in JSON-view of <a href="http://blockexplorer.com/rawblock/0000000000000379bd885d60bcaab9b346a03e9346f310ae3a5ff01cd3770aa5" rel="nofollow">block 200639</a>:</p>

<pre><code>{
    "value":"0.00000000",
    "scriptPubKey":"7ce73474ecef1936fca45fe7835cca09d1a24f52526c189ab40d371b5f69f4a3"
}
</code></pre>

<p>The transaction is valid as the stack will only contain this hash which is not empty and thus evaluates to <code>true</code>. This seems to be a way to save some data in transaction...</p>

<p>Does anyone know for what purpose such scripts may be used?</p>

<script>
scriptPubKey consisting of the only hash
Dmitry
# scriptPubKey consisting of the only hash

(Asked by: username_0 on 2013-12-08)

I found out that some transactions have strange `scriptPubKey` in their outs. They only contain a hash and nothing more. An example can be seen in JSON-view of [block 200639](http://blockexplorer.com/rawblock/0000000000000379bd885d60bcaab9b346a03e9346f310ae3a5ff01cd3770aa5):

```
{
    "value":"0.00000000",
    "scriptPubKey":"7ce73474ecef1936fca45fe7835cca09d1a24f52526c189ab40d371b5f69f4a3"
}

```

The transaction is valid as the stack will only contain this hash which is not empty and thus evaluates to `true`. This seems to be a way to save some data in transaction...

Does anyone know for what purpose such scripts may be used?

**Tags:** script


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## 1 answers

### Answer by username_1 on 2013-12-09. Score: 2

That's a transaction generated by [p2pool](http://p2pool.info/). You assumed correctly in that it is designed to store data, it's used to store some metadata about the current state of the pool. In the future it would probably be better to use `OP_DROP`, as the output is provably unspendable and is able to be pruned from the mempool and blockchain.


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