Date: Tue, 16 Aug 2016 19:30:07 -0700
From: Peter Todd <pete@petertodd.org>
To: "Russell O'Connor" <roconnor@blockstream.io>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Message-ID: <20160817023007.GA7296@fedora-21-dvm>
References: <1736097121.90204.1471369988809@privateemail.com>
	<201608161937.20748.luke@dashjr.org>
	<20160816194332.GA5888@fedora-21-dvm>
	<CAMZUoKkAkGRFxpyGMxQMz76L7uW6fsQAYVxkrxi5MQCiBtNnqw@mail.gmail.com>
	<CAPg+sBi30SgHHXCyipbNpiMRHYWPCRYz6ejQYKrDg3MLJp39EQ@mail.gmail.com>
	<CAMZUoKktS=Ku4kpD0bocR4X__ZpWXrkPkdOyXBaYxjq+mr9Pmw@mail.gmail.com>
	<CAPg+sBhykn8BU1LAr1izH0z6nFuOv0PzWjuqq7YJX5r35LDa9Q@mail.gmail.com>
	<CAMZUoKnebdULkJXqM38i-SkzoD6ufcxdEhcBD1PG5C78qyjFOw@mail.gmail.com>
	<CAAS2fgQ66mQQ6Bdcm7C=CSzjkk3CwZCFLdSsDFdiDaRXhLiO=Q@mail.gmail.com>
	<CAMZUoKm2VX=kL7c3QsenQmQeKnR86APwvdNduDOUtOrtzL2B6A@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
	protocol="application/pgp-signature"; boundary="lrZ03NoBR/3+SXJZ"
Content-Disposition: inline
In-Reply-To: <CAMZUoKm2VX=kL7c3QsenQmQeKnR86APwvdNduDOUtOrtzL2B6A@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Subject: Re: [bitcoin-dev] New BIP: Dealing with OP_IF and OP_NOTIF
 malleability in P2WSH
Precedence: list


--lrZ03NoBR/3+SXJZ
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Tue, Aug 16, 2016 at 08:27:54PM -0400, Russell O'Connor via bitcoin-dev =
wrote:
> Okay.
>=20
> I'm not really opposed to this BIP, but I am worried that fighting script
> malleability is a battle that can never be won; even leaving one avenue of
> malleability open is probably just as bad as having many avenues of
> malleability, so it just doesn't seem worthwhile to me.

At least some types of malleability are less harmful than others: changing a
few bits with some weird ECC transformation isn't as likely to cause proble=
ms
as being able to append arbitrary data to a transaction's input script. And=
 of
course, we do prevent the latter with the cleanstack rule - consensus enfor=
ced
in segwit.

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

--lrZ03NoBR/3+SXJZ
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature

-----BEGIN PGP SIGNATURE-----

iQEcBAEBCAAGBQJXs8wsAAoJEGOZARBE6K+y8HwH/A511FbE5EIirMrmrB/xaRh5
ADy15Gf0wFbJMQf4IQziFnpbVyd/klkiiOuALU/2g+/vCXgkXBOvpwzm4uFb0ta4
3CooFe5KfGkern1lxoGdk2vd6+wlHr02O7Omx+55Wd7647RBqwi3wtwjnR9iInJ+
8f7c6H4t4dINblI8nALQ4F0NSw9+oHSmfBayHRdyXK3UyTrrGqzzOP4Z84sg/gWU
q54KNfjiLrtc2MxO61ROZUTHqg08Bw5IZXQQQF/bAPt7eAQEgdGXCyGJjZjNPuuK
74wihV011IG+XyZ0Pk3XwnjOybuf0qbzq9jl/kRer5cCd7guqfrB3rpTCH76v9U=
=VqSD
-----END PGP SIGNATURE-----

--lrZ03NoBR/3+SXJZ--