Message-ID: <4F4E91FC.6030003@justmoon.de>
Date: Wed, 29 Feb 2012 22:00:44 +0100
From: Stefan Thomas <moon@justmoon.de>
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Subject: Re: [Bitcoin-development] Duplicate transactions vulnerability
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> The purpose of this mail is asking for support for adding this rule to
> the protocol rules. If there is consensus this rule is the solution, I
> hope pools and miners can agree to update their nodes without lengthy
> coinbase-flagging procedure that would only delay a solution. So, who
> is in favor?

Looks good to me. I also second the notion that we should deploy this 
quickly, given that it's a bug fix.


On 2/28/2012 5:48 PM, Pieter Wuille wrote:
> Hello all,
>
> as some of you may know, a vulnerability has been found in how the
> Bitcoin reference client deals with duplicate transactions. Exploiting
> it is rather complex, requires some hash power, and has no financial
> benefit for the attacker. Still, it's a security hole, and we'd like
> to fix this as soon as possible.
>
> A simple way to fix this, is adding an extra protocol rule[1]:
>
>    Do not allow blocks to contain a transaction whose hash is equal to
> that of a former transaction which has not yet been completely spent.
>
> I've written about it in BIP30[2]. There is a patch for the reference
> client, which has been tested and verified to make the attack
> impossible. The change is backward compatible in the same way BIP16
> is: if a supermajority of mining power implements it, old clients can
> continue to function without risk.
>
> The purpose of this mail is asking for support for adding this rule to
> the protocol rules. If there is consensus this rule is the solution, I
> hope pools and miners can agree to update their nodes without lengthy
> coinbase-flagging procedure that would only delay a solution. So, who
> is in favor?
>
>    [1] https://en.bitcoin.it/wiki/Protocol_rules
>    [2] https://en.bitcoin.it/wiki/BIP_0030
>