<oembed><type>rich</type><version>1.0</version><author_name>npub17fjkngg0s0mfx4uhhz6n4puhflwvrhn2h5c78vdr5xda4mvqx89swntr0s</author_name><author_url>https://nostr.ae/npub17fjkngg0s0mfx4uhhz6n4puhflwvrhn2h5c78vdr5xda4mvqx89swntr0s</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2021-04-24&#xA;📝 Original message:&#xA;You&#39;re right, I was thinking about trimmed HTLCs (which can re-appear in&#xA;the commit tx&#xA;if you lower the feerate via update_fee).&#xA;&#xA;Dust HTLCs will never appear in the commit tx regardless of subsequent&#xA;update_fees,&#xA;so Eugene&#39;s suggestion could make sense!&#xA;&#xA;Le sam. 24 avr. 2021 à 06:02, Matt Corallo &lt;lf-lists at mattcorallo.com&gt; a&#xA;écrit :&#xA;&#xA;&gt; The update_fee message does not, as far as I recall, change the dust limit&#xA;&gt; for outputs in a channel (though I’ve suggested making such a change).&#xA;&gt;&#xA;&gt; On Apr 23, 2021, at 12:24, Bastien TEINTURIER &lt;bastien at acinq.fr&gt; wrote:&#xA;&gt;&#xA;&gt; ﻿&#xA;&gt; Hi Eugene,&#xA;&gt;&#xA;&gt; The reason dust HTLCs count for the 483 HTLC limit is because of&#xA;&gt; `update_fee`.&#xA;&gt; If you don&#39;t count them and exceed the 483 HTLC limit, you can&#39;t lower the&#xA;&gt; fee anymore&#xA;&gt; because some HTLCs that were previously dust won&#39;t be dust anymore and you&#xA;&gt; may end&#xA;&gt; up with more than 483 HTLC outputs in your commitment, which opens the&#xA;&gt; door to other&#xA;&gt; kinds of attacks.&#xA;&gt;&#xA;&gt; This is the first issue that comes to mind, but there may be other&#xA;&gt; drawbacks if we dig into&#xA;&gt; this enough with an attacker&#39;s mindset.&#xA;&gt;&#xA;&gt; Bastien&#xA;&gt;&#xA;&gt; Le ven. 23 avr. 2021 à 17:58, Eugene Siegel &lt;elzeigel at gmail.com&gt; a écrit :&#xA;&gt;&#xA;&gt;&gt; I propose a simple mitigation to increase the capital requirement of&#xA;&gt;&gt; channel-jamming attacks. This would prevent an unsophisticated attacker&#xA;&gt;&gt; with low capital from jamming a target channel.  It seems to me that this&#xA;&gt;&gt; is a *free* mitigation without any downsides (besides code-writing), so I&#39;d&#xA;&gt;&gt; like to hear other opinions.&#xA;&gt;&gt;&#xA;&gt;&gt; In a commitment transaction, we trim dust HTLC outputs.  I believe that&#xA;&gt;&gt; the reason for the 483 HTLC limit each side has in the spec is to prevent&#xA;&gt;&gt; commitment tx&#39;s from growing unreasonably large, and to ensure they are&#xA;&gt;&gt; still valid tx&#39;s that can be included in a block.  If we don&#39;t include dust&#xA;&gt;&gt; HTLCs in this calculation, since they are not on the commitment tx, we&#xA;&gt;&gt; still allow 483 (x2) non-dust HTLCs to be included on the commitment tx.&#xA;&gt;&gt; There could be a configurable limit on the number of outstanding dust&#xA;&gt;&gt; HTLCs, but the point is that it doesn&#39;t affect the non-dust throughput of&#xA;&gt;&gt; the channel.  This raises the capital requirement of channel-jamming so&#xA;&gt;&gt; that each HTLC must be non-dust, rather than spamming 1 sat payments.&#xA;&gt;&gt;&#xA;&gt;&gt; Interested in others&#39; thoughts.&#xA;&gt;&gt;&#xA;&gt;&gt; Eugene (Crypt-iQ)&#xA;&gt;&gt; _______________________________________________&#xA;&gt;&gt; Lightning-dev mailing list&#xA;&gt;&gt; Lightning-dev at lists.linuxfoundation.org&#xA;&gt;&gt; https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev&#xA;&gt;&gt;&#xA;&gt; _______________________________________________&#xA;&gt; Lightning-dev mailing list&#xA;&gt; Lightning-dev at lists.linuxfoundation.org&#xA;&gt; https://lists.linuxfoundation.org/mailman/listinfo/lightning-dev&#xA;&gt;&#xA;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20210424/e0afd2d9/attachment.html&gt;</html></oembed>