Date: Wed, 24 Oct 2018 17:52:38 +0000
To: Gregory Maxwell <greg@xiph.org>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
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Subject: Re: [bitcoin-dev] Transaction Input/Output Sorting
Precedence: list

That's pretty easy to quantify. I wrote a quick script to grab the last few=
 blocks, and then shuffle the inputs/outputs before testing if each transac=
tion is bip69 or not.

The result was 42% of all transactions would accidentally be bip69 when ran=
domized.

So clearly randomization is a lot more popular than bip69 at the moment, bu=
t I'm not sure that it matters much. As soon as you have more than a few in=
puts/outputs, you can tell with a high confidence if the transaction is bip=
69 or not.

And of course if you're clustering a wallet, you can figure out extremely e=
asily how that wallet behaves wrt bip6.


-Ryan

=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original Me=
ssage =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90
On Wednesday, October 24, 2018 9:12 AM, Gregory Maxwell via bitcoin-dev <bi=
tcoin-dev@lists.linuxfoundation.org> wrote:

> On Wed, Oct 24, 2018 at 3:52 PM Chris Belcher via bitcoin-dev
> bitcoin-dev@lists.linuxfoundation.org wrote:
>
> > Thanks for bringing our attention to this important topic.
> > According to (https://p2sh.info/dashboard/db/bip-69-stats) around 60% o=
f
> > transaction follow bip69 (possibly just by chance).
>
> A two input randomly ordered transaction has a 50% chance of
> 'following' bip-69. So 60% sound like a small minority.