<oembed><type>rich</type><version>1.0</version><author_name>npub1e46n428mcyfwznl7nlsf6d3s7rhlwm9x3cmkuqzt3emmdpadmkaqqjxmcu</author_name><author_url>https://nostr.ae/npub1e46n428mcyfwznl7nlsf6d3s7rhlwm9x3cmkuqzt3emmdpadmkaqqjxmcu</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;The update_fee message does not, as far as I recall, change the dust limit for outputs in a channel (though I’ve suggested making such a change).&#xA;&#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 `update_fee`.&#xA;&gt; If you don&#39;t count them and exceed the 483 HTLC limit, you can&#39;t lower the fee anymore&#xA;&gt; because some HTLCs that were previously dust won&#39;t be dust anymore and you may end&#xA;&gt; up with more than 483 HTLC outputs in your commitment, which opens the 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 drawbacks if we dig into&#xA;&gt; this enough with an attacker&#39;s mindset.&#xA;&gt; &#xA;&gt; Bastien&#xA;&gt; &#xA;&gt;&gt; Le ven. 23 avr. 2021 à 17:58, Eugene Siegel &lt;elzeigel at gmail.com&gt; a écrit :&#xA;&gt;&gt; I propose a simple mitigation to increase the capital requirement of channel-jamming attacks. This would prevent an unsophisticated attacker with low capital from jamming a target channel.  It seems to me that this is a *free* mitigation without any downsides (besides code-writing), so I&#39;d like to hear other opinions.&#xA;&gt;&gt; &#xA;&gt;&gt; In a commitment transaction, we trim dust HTLC outputs.  I believe that the reason for the 483 HTLC limit each side has in the spec is to prevent commitment tx&#39;s from growing unreasonably large, and to ensure they are still valid tx&#39;s that can be included in a block.  If we don&#39;t include dust HTLCs in this calculation, since they are not on the commitment tx, we still allow 483 (x2) non-dust HTLCs to be included on the commitment tx.  There could be a configurable limit on the number of outstanding dust HTLCs, but the point is that it doesn&#39;t affect the non-dust throughput of the channel.  This raises the capital requirement of channel-jamming so 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; _______________________________________________&#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;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/lightning-dev/attachments/20210424/b09dc276/attachment.html&gt;</html></oembed>