From r.pickhardt at googlemail.com Thu May 26 21:32:30 2022 From: r.pickhardt at googlemail.com (=?UTF-8?Q?Ren=C3=A9_Pickhardt?=) Date: Thu, 26 May 2022 23:32:30 +0200 Subject: [Lightning-dev] Principle Limitations to the reliability of the Lightning Network Protocol Message-ID: Dear fellow lightning developers, please note my recent blog article titled "Price of Anarchy from selfish routing strategies on the Lightning Network" [1] where we investigate how the selfish behavior of nodes sending Bitcoin over the Lightning Network may lead to higher drain on channels which in turn is expected to result in higher depletion and failure rates for payments on the network. All of the observations have been derived purely be looking at statistical measures and computations on the data that the Gossip Protocol and Bitcoin Network provides about the topology of the Lightning Network. No probing or empirical experiments had to be conducted to derive these theoretical results. All code can be found in the lnresearch repository at [2]. While those preliminary results are only presented for some of the strategies that are currently being deployed by `pay` implementations we have not been able yet to study the dynamics of the entire game, secondary effects or to find the dominant strategies of routing and sending nodes. Due to the implications with respect to reliability and payment failure rates - which I assume many have observed in the wild - I thought I would already share these early results with you. While routing nodes seem to be able to mitigate some of the effects we note in the article that it seems as if the routing nodes can hardly engage into selfish behavior or strategies themselves to help with flow and congestion control. This is because it seems as if all operations that we can currently think of that routing nodes could engage in are limited (through protocol design) if applied at scale. E.g: * Adopting fees (limited through gossip relay policies which prevent spam) * Opening / closing channels (limited through block space) * Pro active off chain rebalancing (limited through fees that other nodes charge and the time needed for finding opportunities to conduct rebalancing and the additional load this put to the network ) * Pro active on chain rebalancing (limited through block space and routing fees) I hope the described effects won't be too strong for the expected traffic and usage of the network so that the technology will work properly at the required scale. I am very happy for your thoughts, feedback, comments and questions as I find it fascinating to see how the game theory of the Lightning network will eventually play out and at least in my current understanding seems to produce limitations to the amount of traffic the protocol may eventually be able to handle. with kind Regards Rene Pickhardt [1]: https://blog.bitmex.com/price-of-anarchy-from-selfish-routing-strategies/ [2]: https://github.com/lnresearch/Price-Of-Anarchy-in-Selfish-Routing -------------- next part -------------- An HTML attachment was scrubbed... URL: