path: root/50/aa4b4c12078f2f353cb7d31b83ef2c358ed52c

Return-Path: <gsanders87@gmail.com>
Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138])
 by lists.linuxfoundation.org (Postfix) with ESMTP id 05AD8C002D
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Thu, 16 Jun 2022 01:02:55 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
 by smtp1.osuosl.org (Postfix) with ESMTP id CFC1F83E74
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Thu, 16 Jun 2022 01:02:54 +0000 (UTC)
X-Virus-Scanned: amavisd-new at osuosl.org
X-Spam-Flag: NO
X-Spam-Score: -1.848
X-Spam-Level: 
X-Spam-Status: No, score=-1.848 tagged_above=-999 required=5
 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
 DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,
 FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001,
 HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,
 SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: smtp1.osuosl.org (amavisd-new);
 dkim=pass (2048-bit key) header.d=gmail.com
Received: from smtp1.osuosl.org ([127.0.0.1])
 by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)
 with ESMTP id OYvW1H6nPhV7
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Thu, 16 Jun 2022 01:02:53 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.8.0
Received: from mail-yb1-xb2a.google.com (mail-yb1-xb2a.google.com
 [IPv6:2607:f8b0:4864:20::b2a])
 by smtp1.osuosl.org (Postfix) with ESMTPS id 042A083E44
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Thu, 16 Jun 2022 01:02:52 +0000 (UTC)
Received: by mail-yb1-xb2a.google.com with SMTP id u99so23391569ybi.11
 for <bitcoin-dev@lists.linuxfoundation.org>;
 Wed, 15 Jun 2022 18:02:52 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112;
 h=mime-version:references:in-reply-to:from:date:message-id:subject:to
 :cc; bh=wIQxuWJ8xYDvLF5MXhErQ2jBJh/SRfWteinOj2glRYM=;
 b=i1cshPT8GhgVWdrssmK8+DGwcFkJaZOMhYkOi0VJrG1BvYidK3nkoYoavLwk4p/Qz0
 JXcrDq8efHNgCmqD8HCOMbkqUcOATViSBs1wLc7PUzCQngB6+RAIL/O2Kq8EQZjSfekz
 godg+9RMdvRGpe6vqn/D1alUjK6TB1aRYLg1MSksRVwC05gXWie8zeTnheT6bY5lQP+c
 lnfDixDlc75M5/q01bNx+kqxcHNORbybUVkTNpPaDpSd7mMyu7ejguihkqRUiHbpkQRQ
 vugHHWxxEZPV8Cl67vOapsi7u7hfgjsVs+xqT5jTxTSvowNAntqBxnPyxygJ+6i6cd8D
 lv1w==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=x-gm-message-state:mime-version:references:in-reply-to:from:date
 :message-id:subject:to:cc;
 bh=wIQxuWJ8xYDvLF5MXhErQ2jBJh/SRfWteinOj2glRYM=;
 b=tMDCZbjfhjz6zmlcwAj/Ilev9EOpy9yROjvEFHZ4XD9AKnwEKBV99McJdyxXLRgydh
 LrFKHmxXKTwMeZbsO8l4V12nS5faqw7DDwF8GbsZOhPSrOLgisv5qxHdGJKE1EO0mLX9
 Tec/mLrtKlGg2a0qchny8g66hXVSINrKPteYNs6iamaXFDF2ABt5RhvQbuiwduNkEpCt
 HqQRtDYZW3KGjJ8MQVRGHCZ0Icho+V/lR5B1I0W6OyMKmxTGJbLgRxpPMOvK/+fViak7
 KIkRsdmUAfQtJD8t9lHwGtM3XBtk+fQkg/gLTJ067vJ4YpeqsbjApdN3NCkfIBP1Cwun
 jblw==
X-Gm-Message-State: AJIora9QHoHBxEz7+FjUZsUh+43iRJ+c6NaIsAk9vPqY3YnLpHyRofey
 c2lQa1rCH7Or1wuRE680IUA3jGZKaCoznXHted4=
X-Google-Smtp-Source: AGRyM1uRAVN14yvMEZ5qcjEkb8NEZzYFMiuiSpNADhU+3kI3C+ijT8T3vwwp5bziK3itx5Ilp2BThKD5ewAKZiFLwSw=
X-Received: by 2002:a25:cbc3:0:b0:664:89fb:542b with SMTP id
 b186-20020a25cbc3000000b0066489fb542bmr2957460ybg.23.1655341370615; Wed, 15
 Jun 2022 18:02:50 -0700 (PDT)
MIME-Version: 1.0
References: <CALZpt+GOh-7weEypT9JrzcwthZJqHOfj7sf9FMuqi5_FZv0g7w@mail.gmail.com>
 <7aP7ve-x6uMLSY2a9ZvpkyEc7uOdWmCGOs-S2ly1klRKzm5kVT4zjC9i0V6k1R0Cr9Xloq6Z4zmZ0LfquOxFtyhrA0RgsfG4qq760T4dfZM=@protonmail.com>
In-Reply-To: <7aP7ve-x6uMLSY2a9ZvpkyEc7uOdWmCGOs-S2ly1klRKzm5kVT4zjC9i0V6k1R0Cr9Xloq6Z4zmZ0LfquOxFtyhrA0RgsfG4qq760T4dfZM=@protonmail.com>
From: Greg Sanders <gsanders87@gmail.com>
Date: Wed, 15 Jun 2022 21:02:39 -0400
Message-ID: <CAB3F3DuhMQn_fSiXqqzrUMhDm7D=AiKg4nSO71372WzJFCr9EQ@mail.gmail.com>
To: alicexbt <alicexbt@protonmail.com>, 
 Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: multipart/alternative; boundary="00000000000060a9cf05e186324c"
Subject: Re: [bitcoin-dev] Playing with full-rbf peers for fun and L2s
	security
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>, 
 <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/>
List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org>
List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>, 
 <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe>
X-List-Received-Date: Thu, 16 Jun 2022 01:02:55 -0000

--00000000000060a9cf05e186324c
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

> If something relies on a policy which can be changed without breaking
consensus rules, how is it secure in any case with or without full rbf?

The security of LN and other related systems are something like: "given
proper fees offered, can a transaction be mined within N blocks?" You're
simply not allowed to out-bid your attacker in certain circumstances due to
today's miner incentive-incompatible relay policies.

There is also a time-value dimension to this with other simpler systems
where your funds can be locked up for potentially weeks for similar reasons=
.

>  ... arguments about how many people RBF being sufficient or not ...

The idea that we should only build robust systems after the broken ones are
attacked is not a serious argument.

> I am not opposed to full-rbf; rather, I am opposed to the notion that
full-rbf will solve all problems

This is a strawman.

Full-RBF is a simple, obvious, incentive-compatible step to getting closer
to more robust layer two systems. Fixing the rest of the holes is for
future proposals which are a bit more involved and definitely less mature.

>  would suggest users to try Bitcoin Knots instead
> Developers should provide basic RBF policy options rather than attempting
to define what constitutes a good policy and removing the ability to
disable something when necessary.

If Knots has these knobs, just use Knots rather than lobby all
implementations to have miner incentive incompatible knobs?

Cheers,
Greg

On Wed, Jun 15, 2022 at 8:27 PM alicexbt via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Hi Antoine,
>
>
> Thanks for opening the pull request to add support for full-rbf in Bitcoi=
n
> Core. I have a few disagreements with the approach and questions.
>
> Recent discussions among LN devs have brought back on the surface concern=
s
> about the security of multi-party funded transactions (coinjoins,
> dual-funded LN channels, on-chain DLCs, ...). It turns out there is a
> low-fruit, naive DoS vector playable against the funding flow of any such
> construction due to the lack of existent full-rbf transaction-relay
> topology on today's p2p network [0] [1].
>
>
> 1)If something relies on a policy which can be changed without breaking
> consensus rules, how is it secure in any case with or without full rbf? I=
f
> I write a python script that expects user to enter char 'a' or 'b' but us=
er
> can enter 'c' and there is no code to handle exceptions or other chars,
> will it be secure?
>
> 2)full-rbf is not default in the 2 open pull requests, so this experiment
> still relies on users changing RBF policies manually. If majority of node=
s
> use default opt-in policy, how would this affect vulnerable projects?
>
> If you're a mining operator looking to increase your income, you might be
> interested to experiment with full-rbf as a policy.
>
>
> Miners can only increase their income if users replace transactions. 2-3%
> transactions are replaced with opt-in RBF, if someone did not replace
> earlier why would they do it with full RBF? Or even if we add some users =
in
> it who could not signal for some reasons, do you think it would be anythi=
ng
> above 5%?
>
> If you're a Bitcoin user or business and you don't like full-rbf, please
> express an opinion on how it might affect your software/operations. I'm
> always interested to learn more about mempool and transaction-relay
> interactions with upper-layers and applications and to listen to feedback
> in those areas, and I guess a lot of other Bitcoin researchers/devs too. =
I
> know there have been a lot of concerns about full-rbf in the past, howeve=
r
> I believe the Bitcoin ecosystem has matured a lot since then.
>
>
> I am not opposed to full-rbf; rather, I am opposed to the notion that
> full-rbf will solve all problems and the lack of basic options in Bitcoin
> Core to employ/disable different RBF policies. There is also a speculatio=
n
> about making full RBF default in an year which isn't relevant to discuss =
at
> this point without trying different RBF policies.
>
> I would suggest users to try Bitcoin Knots instead which already has an
> option to disable all RBF policies if required, opt-in and full RBF polic=
y.
> This can also be done using GUI if not familiar with config option
> mempoolreplacement=E2=80=8B.
>
> The rationale in PR #16171 was insufficient to justify removing it in the
> first place, had 2 NACKs and was reopened to merge it. Why bother with a
> few lines of code that may allow someone disable it if required in local
> mempool since it's only useful when a big percentage of miners utilize it
> and essentially underused according to the PR author? Developers should
> provide basic RBF policy options rather than attempting to define what
> constitutes a good policy and removing the ability to disable something
> when necessary.
>
>
> /dev/fd0
>
> Sent with Proton Mail <https://proton.me/> secure email.
>
> ------- Original Message -------
> On Tuesday, June 14th, 2022 at 5:55 AM, Antoine Riard via bitcoin-dev <
> bitcoin-dev@lists.linuxfoundation.org> wrote:
>
> Hi list,
>
> Recent discussions among LN devs have brought back on the surface concern=
s
> about the security of multi-party funded transactions (coinjoins,
> dual-funded LN channels, on-chain DLCs, ...). It turns out there is a
> low-fruit, naive DoS vector playable against the funding flow of any such
> construction due to the lack of existent full-rbf transaction-relay
> topology on today's p2p network [0] [1]. While it does not consist in a
> direct loss of funds, if exploited well I think it's annoying enough to
> inflict significant timevalue loss or fee-bumping waste
> to the future providers or distributed swarm of users doing multi-party
> funded transactions. Of course, it can be fixed one layer above by
> introducing either fidelity bonds or a reliable centralized coordinator,
> though at the price of an overhead per-participant ressources cost and lo=
ss
> in system openness [1].
>
> For that reason, I believe it would be beneficial to the flourishing of
> multi-party funded transactions to fix the Dos vector by seeing a subset =
of
> the network running full-rbf and enabling propagation of honest multi-par=
ty
> transactions to the interested miners, replacing potential non-signaling
> double-spend from a malicious counterparty. Moving towards that direction=
,
> I've submitted a small patch against Bitcoin Core enabling it to turn on
> full-rbf as a policy, still under review [3]. The default setting stays
> **false**, i.e keeping opt-in RBF as a default replacement policy. I've
> started to run the patch on a public node at 146.190.224.15.
>
> If you're a node operator curious to play with full-rbf, feel free to
> connect to this node or spawn up a toy, public node yourself. There is a
> ##uafrbf libera chat if you would like information on the settings or
> looking for full-rbf friends (though that step could be automated in the
> future by setting up a dedicated network bit and reserving a few outbound
> slots for them).
>
> If you're a mining operator looking to increase your income, you might be
> interested to experiment with full-rbf as a policy. Indeed, in the future=
 I
> believe the multi-party transactions issuers who need full-rbf to secure
> their funding flow should connect by default to full-rbf peers. One can
> conjecture that their transactions are likely to be more compelling in
> their feerate as their liquidity needs are higher than the simple
> transaction. For today, I think we have really few standards and bitcoin
> softwares relying on multi-party funded transactions [4].
>
> If you're a Bitcoin user or business and you don't like full-rbf, please
> express an opinion on how it might affect your software/operations. I'm
> always interested to learn more about mempool and transaction-relay
> interactions with upper-layers and applications and to listen to feedback
> in those areas, and I guess a lot of other Bitcoin researchers/devs too. =
I
> know there have been a lot of concerns about full-rbf in the past, howeve=
r
> I believe the Bitcoin ecosystem has matured a lot since then.
>
> Any mistakes or missing context is my own.
>
> Cheers,
> Antoine
>
> [0] For more info about replace-by-fee, see
> https://bitcoinops.org/en/topics/replace-by-fee/
>
> [1] For more details about the DoS vector, see
> https://lists.linuxfoundation.org/pipermail/lightning-dev/2021-May/003033=
.html
>
> [2] E.g I think it does not affect the Lightning Pool service, as there i=
s
> a preliminary step where the participant funds are locked first in a 2-of=
-2
> with the coordinator before being committed in the multi-party batch
> transaction.
>
> [3] https://github.com/bitcoin/bitcoin/pull/25353
>
> [4] E.g DLCs :
> https://github.com/discreetlogcontracts/dlcspecs/blob/master/Transactions=
.md
> ; Lightning dual-funded channel :
> https://github.com/lightning/bolts/pull/851
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

--00000000000060a9cf05e186324c
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">&gt;=C2=A0<span style=3D"font-family:arial;font-size:14px"=
>If something relies on a policy which can be changed without breaking cons=
ensus rules, how is it secure in any case with or without full rbf?</span><=
div><span style=3D"font-family:arial;font-size:14px"><br></span></div><div>=
<span style=3D"font-family:arial;font-size:14px">The security of LN and oth=
er related systems are something like: &quot;given proper fees offered, can=
 a transaction be mined within N blocks?&quot; You&#39;re simply not allowe=
d=C2=A0to out-bid your attacker in certain circumstances due to today&#39;s=
 miner incentive-incompatible=C2=A0relay policies.</span><br></div><div><sp=
an style=3D"font-family:arial;font-size:14px"><br></span></div><div><span s=
tyle=3D"font-family:arial;font-size:14px">There is also a time-value dimens=
ion to this with other simpler systems where your funds can be locked up fo=
r potentially weeks for similar reasons.</span></div><div><font face=3D"ari=
al"><span style=3D"font-size:14px"><br></span></font></div><div><font face=
=3D"arial"><span style=3D"font-size:14px">&gt;=C2=A0 ... a</span></font><sp=
an style=3D"font-family:arial;font-size:14px">rguments about how many peopl=
e RBF being sufficient or not ...</span></div><div><span style=3D"font-fami=
ly:arial;font-size:14px"><br></span></div><div><font face=3D"arial"><span s=
tyle=3D"font-size:14px">The idea that we should only build robust systems a=
fter the broken ones are attacked is not a serious argument.</span></font><=
/div><div><font face=3D"arial"><span style=3D"font-size:14px"><br></span></=
font></div><div><font face=3D"arial"><span style=3D"font-size:14px">&gt;=C2=
=A0</span></font><span style=3D"font-family:arial;font-size:14px">I am not =
opposed to full-rbf; rather, I am opposed to the notion that full-rbf will =
solve all problems</span></div><div><span style=3D"font-family:arial;font-s=
ize:14px"><br></span></div><div><span style=3D"font-family:arial;font-size:=
14px">This is a strawman.</span></div><div><span style=3D"font-family:arial=
;font-size:14px"><br></span></div><div><span style=3D"font-family:arial;fon=
t-size:14px">Full-RBF is a simple, obvious, incentive-compatible step to ge=
tting closer to more robust layer two systems.=C2=A0</span><span style=3D"f=
ont-size:14px;font-family:arial">Fixing the rest of the holes is for future=
 proposals which are a bit more involved and definitely less mature.</span>=
</div><div><br></div><div>&gt;=C2=A0<span style=3D"font-family:arial;font-s=
ize:14px">=C2=A0</span><span style=3D"font-family:arial;font-size:14px">wou=
ld suggest users to try Bitcoin Knots instead</span></div><div>&gt;=C2=A0<s=
pan style=3D"font-family:arial;font-size:14px">Developers should provide ba=
sic RBF policy options rather than attempting to define what constitutes a =
good policy and removing the ability to disable something when necessary.</=
span></div><div><br></div><div>If Knots has these knobs, just use Knots rat=
her than lobby all implementations to have miner incentive incompatible kno=
bs?</div><div><br></div><div>Cheers,</div><div>Greg</div></div><br><div cla=
ss=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Wed, Jun 15, 20=
22 at 8:27 PM alicexbt via bitcoin-dev &lt;<a href=3D"mailto:bitcoin-dev@li=
sts.linuxfoundation.org">bitcoin-dev@lists.linuxfoundation.org</a>&gt; wrot=
e:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0=
.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style=3D=
"font-family:arial;font-size:14px"><span style=3D"color:rgb(34,34,34)">Hi A=
ntoine,</span><div style=3D"color:rgb(34,34,34)"><br></div><div style=3D"co=
lor:rgb(34,34,34)"><br></div><div style=3D"color:rgb(34,34,34)">Thanks for =
opening the pull request to add support for full-rbf in Bitcoin Core. I hav=
e a few disagreements with the approach and questions.</div><div style=3D"c=
olor:rgb(34,34,34)"><br></div><div style=3D"color:rgb(34,34,34)"><blockquot=
e type=3D"cite" style=3D"margin:0px;padding:0px 0px 0px 1rem;font-size:1em;=
border-left:4px solid rgb(229,229,229);color:rgb(0,0,0);font-family:Arial,&=
quot;Helvetica Neue&quot;,Helvetica,sans-serif;background-color:rgb(255,255=
,255)"><span dir=3D"ltr">Recent discussions among LN devs have brought back=
 on the surface concerns about the security of multi-party funded transacti=
ons (coinjoins, dual-funded LN channels, on-chain DLCs, ...). It turns out =
there is a low-fruit, naive DoS vector playable against the funding flow of=
 any such construction due to the lack of existent full-rbf transaction-rel=
ay topology on today&#39;s p2p network [0] [1].<span>=C2=A0</span></span></=
blockquote><br></div><div style=3D"color:rgb(34,34,34)">1)If something reli=
es on a policy which can be changed without breaking consensus rules, how i=
s it secure in any case with or without full rbf? If I write a python scrip=
t that expects user to enter char &#39;a&#39; or &#39;b&#39; but user can e=
nter &#39;c&#39; and there is no code to handle exceptions or other chars, =
will it be secure?=C2=A0=C2=A0</div><div style=3D"color:rgb(34,34,34)"><br>=
</div><div style=3D"color:rgb(34,34,34)">2)full-rbf is not default in the 2=
 open pull requests, so this experiment still relies on users changing RBF =
policies manually. If majority of nodes use default opt-in policy, how woul=
d this affect vulnerable projects?</div><div style=3D"color:rgb(34,34,34)">=
<br></div><div style=3D"color:rgb(34,34,34)"><blockquote type=3D"cite" styl=
e=3D"margin:0px;padding:0px 0px 0px 1rem;font-size:1em;border-left:4px soli=
d rgb(229,229,229);color:rgb(0,0,0);font-family:Arial,&quot;Helvetica Neue&=
quot;,Helvetica,sans-serif;background-color:rgb(255,255,255)"><span dir=3D"=
ltr">If you&#39;re a mining operator looking to increase your income, you m=
ight be interested to experiment with full-rbf as a policy.</span></blockqu=
ote><br></div><div style=3D"color:rgb(34,34,34)">Miners can only increase t=
heir income if users replace transactions. 2-3% transactions are replaced w=
ith opt-in RBF, if someone did not replace earlier why would they do it wit=
h full RBF? Or even if we add some users in it who could not signal for som=
e reasons, do you think it would be anything above 5%?</div><div style=3D"c=
olor:rgb(34,34,34)"><br></div><div style=3D"color:rgb(34,34,34)"><blockquot=
e type=3D"cite" style=3D"margin:0px;padding:0px 0px 0px 1rem;font-size:1em;=
border-left:4px solid rgb(229,229,229);color:rgb(0,0,0);font-family:Arial,&=
quot;Helvetica Neue&quot;,Helvetica,sans-serif;background-color:rgb(255,255=
,255)"><span dir=3D"ltr">If you&#39;re a Bitcoin user or business and you d=
on&#39;t like full-rbf, please express an opinion on how it might affect yo=
ur software/operations. I&#39;m always interested to learn more about mempo=
ol and transaction-relay interactions with upper-layers and applications an=
d to listen to feedback in those areas, and I guess a lot of other Bitcoin =
researchers/devs too. I know there have been a lot of concerns about full-r=
bf in the past, however I believe the Bitcoin ecosystem has matured a lot s=
ince then.</span></blockquote><br></div><div style=3D"color:rgb(34,34,34)">=
<span>I am not opposed to full-rbf; rather, I am opposed to the notion that=
 full-rbf will solve all problems and the lack of basic options in Bitcoin =
Core to employ/disable different RBF policies. There is also a speculation =
about making full RBF default in an year which isn&#39;t relevant to discus=
s at this point without trying different RBF policies.</span></div><div sty=
le=3D"color:rgb(34,34,34)"><br></div><div style=3D"color:rgb(34,34,34)">I w=
ould suggest users to try Bitcoin Knots instead which already has an option=
 to disable all RBF policies if required, opt-in and full RBF policy. This =
can also be done using GUI if not familiar with config option<span>=C2=A0</=
span><code style=3D"font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Co=
nsolas,&quot;Liberation Mono&quot;,&quot;Courier New&quot;,monospace;font-s=
ize:1em;white-space:pre-wrap;background-color:rgba(0,0,0,0)">mempoolreplace=
ment</code>=E2=80=8B.</div><div style=3D"color:rgb(34,34,34)"><br></div><di=
v style=3D"color:rgb(34,34,34)"><span>The rationale in PR #16171 was insuff=
icient to justify removing it in the first place, had 2 NACKs and was reope=
ned to merge it. Why bother with a few lines of code that may allow someone=
 disable it if required in local mempool since it&#39;s only useful when a =
big percentage of miners utilize it and essentially underused according to =
the PR author? Developers should provide basic RBF policy options rather th=
an attempting to define what constitutes a good policy and removing the abi=
lity to disable something when necessary.</span></div><div style=3D"color:r=
gb(34,34,34)"><br></div><div style=3D"color:rgb(34,34,34)"><br></div><span =
style=3D"color:rgb(34,34,34)">/dev/fd0</span><br></div><div style=3D"font-f=
amily:arial;font-size:14px"><br></div>
<div style=3D"font-family:arial;font-size:14px">
    <div>

            </div>

            <div>
        Sent with <a href=3D"https://proton.me/" rel=3D"noopener noreferrer=
" target=3D"_blank">Proton Mail</a> secure email.
    </div>
</div>
<div style=3D"font-family:arial;font-size:14px"><br></div><div>
        ------- Original Message -------<br>
        On Tuesday, June 14th, 2022 at 5:55 AM, Antoine Riard via bitcoin-d=
ev &lt;<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_=
blank">bitcoin-dev@lists.linuxfoundation.org</a>&gt; wrote:<br><br>
        <blockquote type=3D"cite">
            <div dir=3D"ltr">Hi list,<br><br>Recent discussions among LN de=
vs have brought back on the surface concerns about the security of multi-pa=
rty funded transactions (coinjoins, dual-funded LN channels, on-chain DLCs,=
 ...). It turns out there is a low-fruit, naive DoS vector playable against=
 the funding flow of any such construction due to the lack of existent full=
-rbf transaction-relay topology on today&#39;s p2p network [0] [1]. While i=
t does not consist in a direct loss of funds, if exploited well I think it&=
#39;s annoying enough to inflict significant timevalue loss or fee-bumping =
waste <br>to the future providers or distributed swarm of users doing multi=
-party funded transactions. Of course, it can be fixed one layer above by i=
ntroducing either fidelity bonds or a reliable centralized coordinator, tho=
ugh at the price of an overhead per-participant ressources cost and loss in=
 system openness [1].<br><br>For that reason, I believe it would be benefic=
ial to the flourishing of multi-party funded transactions to fix the Dos ve=
ctor by seeing a subset of the network running full-rbf and enabling propag=
ation of honest multi-party transactions to the interested miners, replacin=
g potential non-signaling double-spend from a malicious counterparty. Movin=
g towards that direction, I&#39;ve submitted a small patch against Bitcoin =
Core enabling it to turn on full-rbf as a policy, still under review [3]. T=
he default setting stays **false**, i.e keeping opt-in RBF as a default rep=
lacement policy. I&#39;ve started to run the patch on a public node at 146.=
190.224.15.<br><br>If you&#39;re a node operator curious to play with full-=
rbf, feel free to connect to this node or spawn up a toy, public node yours=
elf. There is a ##uafrbf libera chat if you would like information on the s=
ettings or looking for full-rbf friends (though that step could be automate=
d in the future by setting up a dedicated network bit and reserving a few o=
utbound slots for them).<br><br>If you&#39;re a mining operator looking to =
increase your income, you might be interested to experiment with full-rbf a=
s a policy. Indeed, in the future I believe the multi-party transactions is=
suers who need full-rbf to secure their funding flow should connect by defa=
ult to full-rbf peers. One can conjecture that their transactions are likel=
y to be more compelling in their feerate as their liquidity needs are highe=
r than the simple transaction. For today, I think we have really few standa=
rds and bitcoin softwares relying on multi-party funded transactions [4].<b=
r><br>If you&#39;re a Bitcoin user or business and you don&#39;t like full-=
rbf, please express an opinion on how it might affect your software/operati=
ons. I&#39;m always interested to learn more about mempool and transaction-=
relay interactions with upper-layers and applications and to listen to feed=
back in those areas, and I guess a lot of other Bitcoin researchers/devs to=
o. I know there have been a lot of concerns about full-rbf in the past, how=
ever I believe the Bitcoin ecosystem has matured a lot since then.<br><br>A=
ny mistakes or missing context is my own.<br><br>Cheers,<br>Antoine<br><br>=
[0] For more info about replace-by-fee, see <a href=3D"https://bitcoinops.o=
rg/en/topics/replace-by-fee/" rel=3D"noreferrer nofollow noopener" target=
=3D"_blank">https://bitcoinops.org/en/topics/replace-by-fee/</a><br><br>[1]=
 For more details about the DoS vector, see <a href=3D"https://lists.linuxf=
oundation.org/pipermail/lightning-dev/2021-May/003033.html" rel=3D"noreferr=
er nofollow noopener" target=3D"_blank">https://lists.linuxfoundation.org/p=
ipermail/lightning-dev/2021-May/003033.html</a><br><br>[2] E.g I think it d=
oes not affect the Lightning Pool service, as there is a preliminary step w=
here the participant funds are locked first in a 2-of-2 with the coordinato=
r before being committed in the multi-party batch transaction.<br><br>[3] <=
a href=3D"https://github.com/bitcoin/bitcoin/pull/25353" rel=3D"noreferrer =
nofollow noopener" target=3D"_blank">https://github.com/bitcoin/bitcoin/pul=
l/25353</a><br><br>[4] E.g DLCs : <a href=3D"https://github.com/discreetlog=
contracts/dlcspecs/blob/master/Transactions.md" rel=3D"noreferrer nofollow =
noopener" target=3D"_blank">https://github.com/discreetlogcontracts/dlcspec=
s/blob/master/Transactions.md</a> ; Lightning dual-funded channel : <a href=
=3D"https://github.com/lightning/bolts/pull/851" rel=3D"noreferrer nofollow=
 noopener" target=3D"_blank">https://github.com/lightning/bolts/pull/851</a=
><br></div>

        </blockquote><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>

--00000000000060a9cf05e186324c--