Would that limit the channel to only be alive for 20 minutes? Because if so, that doesn't seem like it would be super helpful. I mean sure you could trade back and forth as many times as you wanted within that 20 minute timeframe. But then once it unlocks the refund transaction could be broadcast and undo it all. So you'd have to make sure to settle the state before the 10 block lock finished. Again, I could be totally off base though.
Tx chaining allows you to sign a tx that has not yet been mined, so for eg. we create a 10 XMR output, then we can immediately sign off a second tx that sends 5 XMR to me and 5 XMR to you even if the first one is not mined yet. That way we could have a "refund" mechanism that was a key thing missing to port the LN to Monero as noted here: https://monero.stackexchange.com/questions/12143/what-parts-of-bitcoins-lightning-network-can-be-ported-to-monero
Even if each tx needs a 10 block lock between another, we don't need each other's private view or spend keys to be online to spend the output so we are safe that the "refund" tx can be broadcast and mined
This allows us to create some payment channel designs as kayaba notes here: https://x.com/kayabaNerve/status/1788959848110985658
His latest comment on it (timestamped):
https://www.youtube.com/live/jxPulIjhXwg?si=yA4GfbOKXl6JXRbL&t=5847
Discussion
It would need a timelock mechanism as well like it works on BTC so that if there is a newer channel state, like you sent me 1 XMR and the balance is now [ me: 6 XMR <-> 4 XMR: you ] and you try to cheat by publishing the old [ 5 <-> 5 ] XMR state in this 20min window I need time to come back online and broadcast the latest state on-chain and redeem the funds before you are able to broadcast the theft attempt, still not super sure how all of this would work on XMR vs BTC, but this way we can basically let the channel live forever and the optmistic path is we send LN-moneros back and forth no need to close as soon as possible
I believe that Monero did have a timelock mechanism in the recent past, and it was deprecated or removed for some reason. But I do feel like I remember it being discussed. I want to say there was concern about it being unlimited and so you could lock somebody's Monero for like thousands of years and they wouldn't be able to do anything about it.
yeah but there are other papers describing other ways to achieve this as well, like https://eprint.iacr.org/2020/1441 which they call "time lock puzzles" instead, without using the protocol, which sounds like PoW for a few days of time, not sure which method will be preferred by then
There's a lot of really, really smart people working on Monero. That's for sure.