Date: Tue, 28 Feb 2012 21:24:15 +0100
From: Pieter Wuille <pieter.wuille@gmail.com>
To: Luke-Jr <luke@dashjr.org>
Message-ID: <20120228202414.GA16255@vps7135.xlshosting.net>
References: <CAPg+sBhb+gYMwp1OJuCHYt5=BU63=YBWOFaLLthHBkN_U-scaA@mail.gmail.com>
	<201202281323.02976.luke@dashjr.org>
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Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Duplicate transactions vulnerability
Precedence: list

On Tue, Feb 28, 2012 at 01:23:01PM -0500, Luke-Jr wrote:
> Has it been verified to make even rocconor's complicated transaction-based 
> version impossible?

Yes, he tried it on testnet against a patched node.

> > 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?
> 
> Can we do this in two steps? First, prefer blocks which don't break the rule; 
> once 55%+ are confirmed to have upgraded, then it is safe to treat it as a 
> hard rule.

I prefer to avoid this if possible, as it increases the size of the patch
significantly. In particular, it would require the discouragement-system to
be backported to whatever versions pools are running. The current proposal
only requires adding 6 lines of code.

-- 
Pieter