MIME-Version: 1.0
References: <uOr9bwW2C0lwMSiUOEie2rzyrA7uE4Rm7kVnU2FnF9jyMGjYDvN0WhDM6QbZ_XxNlu44WqE7meXBZAeHAd94DAWnYcSBOPuo4nb4UQp2Wmk=@protonmail.com>
 <CAHUJnBCrw0n_9=2gugMhTW6QCjStBFxEsGrF=BY9JX806OurXQ@mail.gmail.com>
 <20220308012719.GA6992@erisian.com.au>
 <CAHUJnBDR-zQa0uBRorWkVf7CO+oS-J3zJU7B8K9cA_+7vqa=Dg@mail.gmail.com>
 <20220310064717.GA7597@erisian.com.au>
In-Reply-To: <20220310064717.GA7597@erisian.com.au>
From: Bram Cohen <bram@chia.net>
Date: Tue, 15 Mar 2022 23:45:48 -0700
Message-ID: <CAHUJnBDX5_HkocD4DMT05g59aWyrYMt=dDEBS_3hraJMoVOSXA@mail.gmail.com>
To: Anthony Towns <aj@erisian.com.au>
Content-Type: multipart/alternative; boundary="00000000000021add405da504484"
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] bitcoin scripting and lisp
Precedence: list

--00000000000021add405da504484
Content-Type: text/plain; charset="UTF-8"

On Wed, Mar 9, 2022 at 10:47 PM Anthony Towns <aj@erisian.com.au> wrote:

>
> To redo the singleton pattern in bitcoin's context, I think you'd have
> to pass in both the full tx you're spending (to be able to get the
> txid of its parent) and the full tx of its parent (to be able to get
> the scriptPubKey that your utxo spent) which seems klunky but at least
> possible (you'd be able to drop the witness data at least; without that
> every tx would be including the entire history of the singleton).
>

Yes that's the idea. Since the parent transaction is in the blockchain it
could be pulled in automatically without having to charge vbytes for it.


> If softfork is just doing a best effort for whatever opcodes it knows
> about, and otherwise succeeding, then it has to succeed, and your
> script/output has become anyone-can-spend.
>

That can be alleviated by when things call untrusted code they can wrap it
in a guard which can be the soft fork opcode itself.


>
> On the other hand, if you could tell the softfork op that you only wanted
> ops up-to-and-including the 118 softfork, then it could reject fakeopcode
> and fail the script, which I think gives the desirable behaviour.
>

A simple approach to versioning like that may be more expedient. Soft
forking in CLVM isn't implemented yet.

--00000000000021add405da504484
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div dir=3D"ltr">On Wed, Mar 9, 2022 at 10:47 PM Anthony T=
owns &lt;<a href=3D"mailto:aj@erisian.com.au">aj@erisian.com.au</a>&gt; wro=
te:<br></div><div class=3D"gmail_quote"><blockquote class=3D"gmail_quote" s=
tyle=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);pad=
ding-left:1ex"><br>
To redo the singleton pattern in bitcoin&#39;s context, I think you&#39;d h=
ave<br>
to pass in both the full tx you&#39;re spending (to be able to get the<br>
txid of its parent) and the full tx of its parent (to be able to get<br>
the scriptPubKey that your utxo spent) which seems klunky but at least<br>
possible (you&#39;d be able to drop the witness data at least; without that=
<br>
every tx would be including the entire history of the singleton).<br></bloc=
kquote><div><br></div><div>Yes that&#39;s the idea. Since the parent transa=
ction is in the blockchain it could be pulled in automatically without havi=
ng to charge vbytes for it.</div><div>=C2=A0</div><blockquote class=3D"gmai=
l_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,20=
4,204);padding-left:1ex">If softfork is just doing a best effort for whatev=
er opcodes it knows<br>
about, and otherwise succeeding, then it has to succeed, and your<br>
script/output has become anyone-can-spend.<br></blockquote><div><br></div><=
div>That can be alleviated by when things call untrusted code they can wrap=
 it in a guard which can be the soft fork opcode itself.</div><div>=C2=A0</=
div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;bor=
der-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
On the other hand, if you could tell the softfork op that you only wanted<b=
r>
ops up-to-and-including the 118 softfork, then it could reject fakeopcode<b=
r>
and fail the script, which I think gives the desirable behaviour.<br></bloc=
kquote><div><br></div><div>A simple approach to versioning like that may be=
 more expedient. Soft forking in CLVM isn&#39;t implemented yet.</div></div=
></div>

--00000000000021add405da504484--