<oembed><type>rich</type><version>1.0</version><author_name>npub1xqcwcttsyk0a64d63crrwsxp88pa42np37rw87hrfn4uku78g2aqltcnns</author_name><author_url>https://nostr.ae/npub1xqcwcttsyk0a64d63crrwsxp88pa42np37rw87hrfn4uku78g2aqltcnns</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2021-07-05&#xA;📝 Original message:@ ZmnSCPxj, Good Evening&#xA;&#xA;&gt;  The two participants in the channel can sign a plaintext containing&#xA;their node pubkeys and how much each owns&#xA;&#xA;Sure, but even if both participants in the channel sign a correct statement&#xA;of truth, one of the participants can send funds out in the next second,&#xA;invalidating that truth. While proof of ownership of on-chain UTXOs can be&#xA;seen publicly in real time if they are spent, LN transactions aren&#39;t public&#xA;like that. So any balance attestation is at best only valid the instant its&#xA;taken, and can&#39;t be used as verification the money is still owned by the&#xA;same channel partner in the next second.&#xA;&#xA;&gt;  a custodian Lightning node is unable to &#34;freeze&#34; a snapshot of its&#xA;current state and make an atomic proof-of-reserves of *all* channels&#xA;&#xA;That would be a neat trick. But yeah, I don&#39;t know how that would be&#xA;possible.&#xA;&#xA;&gt;  I believe it is one reason why custodian proof-of-reserves is not that&#xA;popular ... it does not prove that the key will not get lost&#xA;&#xA;True, but at least if funds do get lost, it would be come clear far&#xA;quicker. Today, an insolvent company could go many months without the&#xA;public finding out.&#xA;&#xA;On Mon, Jul 5, 2021 at 5:09 PM ZmnSCPxj &lt;ZmnSCPxj at protonmail.com&gt; wrote:&#xA;&#xA;&gt; Good morning e,&#xA;&gt;&#xA;&gt;&#xA;&gt; &gt; If only one could prove that he won’t get into a boating accident.&#xA;&gt;&#xA;&gt; At least in the context of Lightning channels, if one party in the channel&#xA;&gt; loses its key in a boating accident, the other party (assuming it is a true&#xA;&gt; separate person and not a sockpuppet) has every incentive to unilaterally&#xA;&gt; close the channel, which reveals the exact amounts (though not necessarily&#xA;&gt; who owns which).&#xA;&gt; If the other party then uses its funds in a new proof-of-reserves, then&#xA;&gt; obviously the other output of the unilateral close was the one lost in the&#xA;&gt; boating accident.&#xA;&gt;&#xA;&gt; On the other hand, yes, custodians losing custodied funds in boating&#xA;&gt; accidents is much too common.&#xA;&gt; I believe it is one reason why custodian proof-of-reserves is not that&#xA;&gt; popular --- it only proves that the funds were owned under a particular key&#xA;&gt; at some snapshot of the past, it does not prove that the key will not get&#xA;&gt; lost (or &#34;lost and then salvaged by a scuba diver&#34;) later.&#xA;&gt;&#xA;&gt;&#xA;&gt; Regards,&#xA;&gt; ZmnSCPxj&#xA;&gt;&#xA;&gt; &gt;&#xA;&gt; &gt; e&#xA;&gt; &gt;&#xA;&gt; &gt; &gt; On Jul 5, 2021, at 16:26, ZmnSCPxj via bitcoin-dev&#xA;&gt; bitcoin-dev at lists.linuxfoundation.org wrote:&#xA;&gt; &gt; &gt; Good morning Billy,&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; &gt; I wonder if there would be some way to include the ability to prove&#xA;&gt; balances held on the lightning network, but I suspect that isn&#39;t generally&#xA;&gt; possible.&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; Thinking about this in terms of economic logic:&#xA;&gt; &gt; &gt; Every channel is anchored onchain, and that anchor (the funding txout)&#xA;&gt; is proof of the existence, and size, of the channel.&#xA;&gt; &gt; &gt; The two participants in the channel can sign a plaintext containing&#xA;&gt; their node pubkeys and how much each owns.&#xA;&gt; &gt; &gt; One of the participants should provably be the custodian.&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; -   If the counterparty is a true third party, it has no incentive to&#xA;&gt; lie about its money.&#xA;&gt; &gt; &gt; -   Especially if the counterparty is another custodian who wants&#xA;&gt; proof-of-reserves, it has every incentive to overreport, but then the first&#xA;&gt; party will refuse to sign.&#xA;&gt; &gt; &gt;     It has a disincentive to underreport, and would itself refuse to&#xA;&gt; sign a dishonest report that assigns more funds to the first party.&#xA;&gt; &gt; &gt;     The only case that would be acceptable to both custodians would be&#xA;&gt; to honestly report their holdings in the Lightning channel.&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; -   If the counterparty is a sockpuppet of the custodian, then the&#xA;&gt; entire channel is owned by the custodian and it would be fairly dumb of he&#xA;&gt; custodian to claim to have less funds than the entire channel.&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; Perhaps a more practical problem is that Lightning channel states&#xA;&gt; change fairly quickly, and there are possible race conditions, due to&#xA;&gt; network latency (remember, both nodes need to sign, meaning both of them&#xA;&gt; need to communicate with each other, thus hit by network latency and other&#xA;&gt; race conditions) where a custodian Lightning node is unable to &#34;freeze&#34; a&#xA;&gt; snapshot of its current state and make an atomic proof-of-reserves of all&#xA;&gt; channels.&#xA;&gt; &gt; &gt; Regards,&#xA;&gt; &gt; &gt; ZmnSCPxj&#xA;&gt; &gt; &gt;&#xA;&gt; &gt; &gt; bitcoin-dev mailing list&#xA;&gt; &gt; &gt; bitcoin-dev at lists.linuxfoundation.org&#xA;&gt; &gt; &gt; https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev&#xA;&gt;&#xA;&gt;&#xA;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20210705/8f6b1e68/attachment-0001.html&gt;</html></oembed>