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From: Chris Stewart <chris@suredbits.com>
To: Johnson Lau <jl2012@xbt.hk>,
	 Bitcoin Protocol Discussion
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Disallow insecure use of SIGHASH_SINGLE
Date: Tue, 5 Jun 2018 19:17:52 -0500	[thread overview]
Message-ID: <CAGL6+mH3ah_e-+e0=ce0-HmkaqU1YzoGNS5JXCXDbojxpVvX8Q@mail.gmail.com> (raw)
In-Reply-To: <9FC9FA73-9572-48AF-9590-68F0D298D6A0@xbt.hk>

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Do you have any thoughts on expanding this to SIGHASH_NONE? Perhaps someone
else on the dev list can enlighten me, but is there a current use case for
SIGHASH_NONE that would suffer from it being non standard?

-Chris


On Thu, May 31, 2018 at 1:53 PM, Johnson Lau via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> I’ve made a PR to add a new policy to disallow using SIGHASH_SINGLE
> without matched output:
>
> https://github.com/bitcoin/bitcoin/pull/13360
>
> Signature of this form is insecure, as it commits to no output while users
> might think it commits to one. It is even worse in non-segwit scripts,
> which is effectively SIGHASH_NOINPUT|SIGHASH_NONE, so any UTXO of the same
> key could be stolen. (It’s restricted to only one UTXO in segwit, but it’s
> still like a SIGHASH_NONE.)
>
> This is one of the earliest unintended consensus behavior. Since these
> signatures are inherently unsafe, I think it does no harm to disable this
> unintended “feature” with a softfork. But since these signatures are
> currently allowed, the first step is to make them non-standard.
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

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  reply	other threads:[~2018-06-06  0:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-31 18:53 [bitcoin-dev] Disallow insecure use of SIGHASH_SINGLE Johnson Lau
2018-06-06  0:17 ` Chris Stewart [this message]
2018-06-06  0:43   ` Peter Todd
2018-06-06  0:49 ` Peter Todd

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