<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:2021-04-23&#xA;📝 Original message:&#xA;Hi Eugene,&#xA;&#xA;The reason dust HTLCs count for the 483 HTLC limit is because of&#xA;`update_fee`.&#xA;If you don&#39;t count them and exceed the 483 HTLC limit, you can&#39;t lower the&#xA;fee anymore&#xA;because some HTLCs that were previously dust won&#39;t be dust anymore and you&#xA;may end&#xA;up with more than 483 HTLC outputs in your commitment, which opens the door&#xA;to other&#xA;kinds of attacks.&#xA;&#xA;This is the first issue that comes to mind, but there may be other&#xA;drawbacks if we dig into&#xA;this enough with an attacker&#39;s mindset.&#xA;&#xA;Bastien&#xA;&#xA;Le ven. 23 avr. 2021 à 17:58, Eugene Siegel &lt;elzeigel at gmail.com&gt; a écrit :&#xA;&#xA;&gt; I propose a simple mitigation to increase the capital requirement of&#xA;&gt; channel-jamming attacks. This would prevent an unsophisticated attacker&#xA;&gt; with low capital from jamming a target channel.  It seems to me that this&#xA;&gt; is a *free* mitigation without any downsides (besides code-writing), so I&#39;d&#xA;&gt; like to hear other opinions.&#xA;&gt;&#xA;&gt; In a commitment transaction, we trim dust HTLC outputs.  I believe that&#xA;&gt; the reason for the 483 HTLC limit each side has in the spec is to prevent&#xA;&gt; commitment tx&#39;s from growing unreasonably large, and to ensure they are&#xA;&gt; still valid tx&#39;s that can be included in a block.  If we don&#39;t include dust&#xA;&gt; HTLCs in this calculation, since they are not on the commitment tx, we&#xA;&gt; still allow 483 (x2) non-dust HTLCs to be included on the commitment tx.&#xA;&gt; There could be a configurable limit on the number of outstanding dust&#xA;&gt; HTLCs, but the point is that it doesn&#39;t affect the non-dust throughput of&#xA;&gt; the channel.  This raises the capital requirement of channel-jamming so&#xA;&gt; that each HTLC must be non-dust, rather than spamming 1 sat payments.&#xA;&gt;&#xA;&gt; Interested in others&#39; thoughts.&#xA;&gt;&#xA;&gt; Eugene (Crypt-iQ)&#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;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20210423/9068d4e9/attachment-0001.html&gt;</html></oembed>