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Bitcoin Dev Archive 2012

Zero-length scripts

2 messages, 12 to 13 Dec 2012. Started by Eric Lombrozo.

Eric Lombrozo, Michael Gronager

Permalink Original thread on gnusha.org

Eric Lombrozo permalink original

I've noticed a few transactions that have zero-length input and/or output scripts. There's a couple examples in block 0000000000000159a27442ee8b7f9ffad0cd799b003eafe007de9fbb47bd6ce7:

Txs: cdb553214a51ef8d4393b96a185ebbbc2c84b7014e9497fea8aec1ff990dae35, af32bb06f12f2ae5fdb7face7cd272be67c923e86b7a66a76ded02d954c2f94d

Is there ever a legitimate reason to create a transaction with a zero-length script? Should the protocol even allow it?

-Eric Lombrozo

Michael Gronager in reply to Eric Lombrozo permalink original

Normally I would consider it an error of the parsing script of blockchain (seen that before), however, this seems genuine enough.

the second transaction is the most amusing - it has an output script which is: OP_HASH256 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f OP_EQUAL

The hash is the most famous bitcoin hash... - so if you can come up with something that, when hashed with sha256 yields the genesisblock hash you can claim one BTC ;)

It is actually very easy to do (!), however, it is a game only for miners, as non_standard transactions are not relayed between standard clients. So now a miner can have a go creating a transaction redeeming this 1BTC.

Perhaps, Eligius creating that block, might be playing a little christmas game :)

Cheers,

Michael

On 12/12/2012, at 23:09, Eric Lombrozo <elombrozo@gmail•com> wrote:

Quoted text (18 lines)
> I've noticed a few transactions that have zero-length input and/or output scripts. There's a couple examples in block 0000000000000159a27442ee8b7f9ffad0cd799b003eafe007de9fbb47bd6ce7:
>
> Txs: cdb553214a51ef8d4393b96a185ebbbc2c84b7014e9497fea8aec1ff990dae35, af32bb06f12f2ae5fdb7face7cd272be67c923e86b7a66a76ded02d954c2f94d
>
>
> Is there ever a legitimate reason to create a transaction with a zero-length script? Should the protocol even allow it?
>
> -Eric Lombrozo
>
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