MIME-Version: 1.0
References: <6by5pfnBrFYUmFpOtTRyZ0YIxJaKyaJ1tqW3s26_ZHeGZIJssZY0kLvmYqXtoXRK-mMoMbDY-dmKw_mlCUCDYlzolM25ZvkLpr6pvh8t2LY=@cybriq.systems>
 <Z9_T0sYBHcJS5M21tyvXa6vAhC1YamBRXzTCll31M4peuHdbo25v4rnycfTbZOgNgmxA4rzTGLuU4lxT9o6tft90N_7-pfAgiY8_2BAX4w8=@cybriq.systems>
In-Reply-To: <Z9_T0sYBHcJS5M21tyvXa6vAhC1YamBRXzTCll31M4peuHdbo25v4rnycfTbZOgNgmxA4rzTGLuU4lxT9o6tft90N_7-pfAgiY8_2BAX4w8=@cybriq.systems>
From: Greg Sanders <gsanders87@gmail.com>
Date: Tue, 11 Oct 2022 09:06:37 -0400
Message-ID: <CAB3F3Dt7g=_roqWabQxs6RA96foUzbJePV154Dhc-d9WirQ+wg@mail.gmail.com>
To: Loki Verloren <loki@cybriq.systems>, 
 Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: multipart/alternative; boundary="0000000000004a784605eac1f3f8"
Subject: Re: [bitcoin-dev] Minor DoS vulnerability in BIP144 lack of tx
 witness data size limit
Precedence: list

--0000000000004a784605eac1f3f8
Content-Type: text/plain; charset="UTF-8"

There are a number of issues with adding arbitrary size restrictions to
consensus(I personally think it's additional complexity for negative gain),
but most of all this may resolve in burned coins.

On Tue, Oct 11, 2022 at 6:22 AM Loki Verloren via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

>
> The recent 998 of 999 multisig segwit transaction highlights a problem
> with BIP144. As the solution applied for btcd shows, effectively a single
> transaction witness can be the same as the maximum block size.
>
> 11000 bytes may not be so unreasonable but now there is a special case
> with a block over 33k worth of witness data.
>
> A concrete limit should be set on the maximum size of a transaction
> witness, and this should be discussed in a more general sense about total
> transaction sizes.
>
> In the absence of a specification, it becomes impossible to properly
> implement and the status quo devolves to the actual implementation in the
> bitcoin core repository code.
>
> I think the weight calculation should escalate exponentially to discourage
> putting transactions like this on the chain. The price was equivalent to
> about $5 to do this.
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

--0000000000004a784605eac1f3f8
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><font face=3D"Arial"><span style=3D"font-size:14px">There =
are a number of issues with adding arbitrary size restrictions to consensus=
(I personally think it&#39;s additional complexity for negative gain), but =
most of all this may resolve=C2=A0in burned coins.</span></font></div><br><=
div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, Oct=
 11, 2022 at 6:22 AM Loki Verloren via bitcoin-dev &lt;<a href=3D"mailto:bi=
tcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.linuxfoundation.org<=
/a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0=
px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><=
div style=3D"font-family:Arial;font-size:14px"><br></div><div>
       =20
            <div style=3D"font-family:Arial;font-size:14px"><span>The recen=
t 998 of 999 multisig segwit transaction highlights a problem with BIP144. =
As the solution applied for btcd shows, effectively a single transaction wi=
tness can be the same as the maximum block size.</span><div><br></div><div>=
<span>11000 bytes may not be so unreasonable but now there is a special cas=
e with a block over 33k worth of witness data.</span></div><div><br></div><=
div><span>A concrete limit should be set on the maximum size of a transacti=
on witness, and this should be discussed in a more general sense about tota=
l transaction sizes.</span></div><div><br></div><div><span>In the absence o=
f a specification, it becomes impossible to properly implement and the stat=
us quo devolves to the actual implementation in the bitcoin core repository=
 code.</span></div><div><br></div><div>I think the weight calculation shoul=
d escalate exponentially to discourage putting transactions like this on th=
e chain. The price was equivalent to about $5 to do this.</div></div><div s=
tyle=3D"font-family:Arial;font-size:14px">
</div>

        <br>
    </div>_______________________________________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">=
bitcoin-dev@lists.linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev</a><br>
</blockquote></div>

--0000000000004a784605eac1f3f8--