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In-Reply-To: <Y92GY7s1U4P9fC/f@petertodd.org>
From: Greg Sanders <gsanders87@gmail.com>
Date: Fri, 3 Feb 2023 21:07:29 -0500
Message-ID: <CAB3F3Dtuxu8m6+pU_xBwh=35MyPF90OSnB4vhaNbKpr_ap2shw@mail.gmail.com>
To: Peter Todd <pete@petertodd.org>
Content-Type: multipart/alternative; boundary="0000000000004891cc05f3d643e2"
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Ephemeral Anchors: Fixing V3 Package RBF
 againstpackage limit pinning
Precedence: list

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I'm not particularly persuaded, but also not wedded to either idea.

Fixed up tests for the OP_TRUE case here:
https://github.com/instagibbs/bitcoin/tree/ephemeral-anchors-true

On Fri, Feb 3, 2023 at 5:10 PM Peter Todd <pete@petertodd.org> wrote:

> On Thu, Feb 02, 2023 at 03:47:28PM -0500, Greg Sanders wrote:
> > > OP_TRUE is the obvious way to do this, and it results with a 1 on the
> > stack,
> > which plays better with other standardness rules.
> >
> > What other standardness rules? MINAMALIF? How does that interact with the
> > proposal?
>
> It makes sense to require scripts to leave just a single OP_TRUE on the
> stack
> at the end of execution, as otherwise that can be a source of malleability
> in
> certain circumstances where the scriptSig ends up providing the OP_TRUE. I
> don't believe we actually implement this as a rule right now. But you could
> easily imagine that happening in a future upgrade.
>
> Leaving an OP_2 on the stack doesn't achieve that and would require a
> special-cased workaround. Spending the time now to do the obvious thing -
> use
> OP_TRUE as the canonical anyone-can-spend output - avoids this issue.
>
> --
> https://petertodd.org 'peter'[:-1]@petertodd.org
>

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<div dir=3D"ltr">I&#39;m not particularly persuaded, but also not wedded to=
 either idea.<div><br></div><div>Fixed up tests for the OP_TRUE case here:=
=C2=A0<a href=3D"https://github.com/instagibbs/bitcoin/tree/ephemeral-ancho=
rs-true">https://github.com/instagibbs/bitcoin/tree/ephemeral-anchors-true<=
/a></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gma=
il_attr">On Fri, Feb 3, 2023 at 5:10 PM Peter Todd &lt;<a href=3D"mailto:pe=
te@petertodd.org">pete@petertodd.org</a>&gt; wrote:<br></div><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid=
 rgb(204,204,204);padding-left:1ex">On Thu, Feb 02, 2023 at 03:47:28PM -050=
0, Greg Sanders wrote:<br>
&gt; &gt; OP_TRUE is the obvious way to do this, and it results with a 1 on=
 the<br>
&gt; stack,<br>
&gt; which plays better with other standardness rules.<br>
&gt; <br>
&gt; What other standardness rules? MINAMALIF? How does that interact with =
the<br>
&gt; proposal?<br>
<br>
It makes sense to require scripts to leave just a single OP_TRUE on the sta=
ck<br>
at the end of execution, as otherwise that can be a source of malleability =
in<br>
certain circumstances where the scriptSig ends up providing the OP_TRUE. I<=
br>
don&#39;t believe we actually implement this as a rule right now. But you c=
ould<br>
easily imagine that happening in a future upgrade.<br>
<br>
Leaving an OP_2 on the stack doesn&#39;t achieve that and would require a<b=
r>
special-cased workaround. Spending the time now to do the obvious thing - u=
se<br>
OP_TRUE as the canonical anyone-can-spend output - avoids this issue.<br>
<br>
-- <br>
<a href=3D"https://petertodd.org" rel=3D"noreferrer" target=3D"_blank">http=
s://petertodd.org</a> &#39;peter&#39;[:-1]@<a href=3D"http://petertodd.org"=
 rel=3D"noreferrer" target=3D"_blank">petertodd.org</a><br>
</blockquote></div>

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