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Date: Thu, 11 Apr 2013 07:27:08 -0400
From: Peter Todd <pete@petertodd.org>
To: Jorge =?iso-8859-1?Q?Tim=F3n?= <jtimon@monetize.io>
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Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development]
 =?utf-8?q?To_prevent_arbitrary_data_storage?=
 =?utf-8?q?_in_txouts_=E2=80=94_The_Ultimate_Solution?=
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On Wed, Apr 10, 2013 at 05:58:10PM +0200, Jorge Tim=F3n wrote:
> On 4/10/13, Peter Todd <pete@petertodd.org> wrote:
> > Oh, and while we're at it, long-term (hard-fork) it'd be good to change
> > the tx hash algorithm to extend the merkle tree into the txouts/txins
> > itself, which means that to prove a given txout exists you only need to
> > provide it, rather than the full tx.
> >
> > Currently pruning can't prune a whole tx until every output is spent.
> > Make that change and we can prune tx's bit by bit, and still be able to
> > serve nodes requesting proof of their UTXO without making life difficult
> > for anyone trying to spent old UTXO's. The idea is also part of UTXO
> > proof stuff anyway.
>=20
> I thought about this before, I like the idea very much.
> Would such a fork be controversial for anyone?
> Would anyone oppose to this for some reason I'm missing?

You mean https://bitcointalk.org/index.php?topic=3D137933.0 ?

I would oppose it, and I wrote the above proposal. The code required to
implement UTXO fraud proofs is more complex than the entire Bitcoin code
base; obviously that much new fork-critical code opens up huge technical
risks. As an example, can you think of how UTXO fraud proofs can cause
an arbitrarily deep re-org?

--=20
'peter'[:-1]@petertodd.org

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