From ZmnSCPxj at protonmail.com Fri Oct 12 03:20:55 2018 From: ZmnSCPxj at protonmail.com (ZmnSCPxj) Date: Fri, 12 Oct 2018 03:20:55 +0000 Subject: [Lightning-dev] eltoo: A Simplified update Mechanism for Lightning and Off-Chain Contracts In-Reply-To: References: <874ljsitvx.fsf@gmail.com> <20181010082546.76h34hw7bmtse4wq@erisian.com.au> Message-ID: Another way would be to always have two update transactions, effectively creating a larger overall counter: [anchor] -> [update highbits] -> [update lobits] -> [settlement] We normally update [update lobits] until it saturates. If lobits saturates we increment [update highbits] and reset [update lobits] to the lowest valid value. This will provide a single counter with 10^18 possible updates, which should be enough for a while even without reanchoring. Regards, ZmnSCPxj Sent with [ProtonMail](https://protonmail.com) Secure Email. ??????? Original Message ??????? On Friday, October 12, 2018 1:37 AM, Christian Decker wrote: > Thanks Anthony for pointing this out, I was not aware we could > roll keypairs to reset the state numbers. > > I basically thought that 1billion updates is more than I would > ever do, since with splice-in / splice-out operations we'd be > re-anchoring on-chain on a regular basis anyway. > > On Wed, Oct 10, 2018 at 10:25 AM Anthony Towns wrote: > >> On Mon, Apr 30, 2018 at 05:41:38PM +0200, Christian Decker wrote: >>> eltoo is a drop-in replacement for the penalty based invalidation >>> mechanism that is used today in the Lightning specification. [...] >> >> Maybe this is obvious, but in case it's not, re: the locktime-based >> sequencing in eltoo: >> >> "any number above 0.500 billion is interpreted as a UNIX timestamp, and >> with a current timestamp of ~1.5 billion, that leaves about 1 billion >> numbers that are interpreted as being in the past" >> >> I think if you had a more than a 1B updates to your channel (50 updates >> per second for 4 months?) I think you could reset the locktime by rolling >> over to use new update keys. When unilaterally closing you'd need to >> use an extra transaction on-chain to do that roll-over, but you'd save >> a transaction if you did a cooperative close. >> >> ie, rather than: >> >> [funding] -> [coop close / re-fund] -> [update 23M] -> [HTLCs etc] >> or >> [funding] -> [coop close / re-fund] -> [coop close] >> >> you could have: >> [funding] -> [update 1B] -> [update 23,310,561 with key2] -> [HTLCs] >> or >> [funding] -> [coop close] >> >> You could repeat this when you get another 1B updates, making unilateral >> closes more painful, but keeping cooperative closes cheap. >> >> Cheers, >> aj -------------- next part -------------- An HTML attachment was scrubbed... URL: