Lightning Specification Meeting 2023/03/13

[t-bast]

Lightning Specification Meeting 2023/03/13

[t-bast]

I won't be able to attend this spec meeting, I'll be traveling at that time.

On route blinding, I'd like feedback from the crowd on this comment: should this feature bit be marked as an invoice feature bit or not? It is conceptually an invoice feature, so it bothers me a bit to only mark it IN, even though nobody plans on supporting route blinding with Bolt 11 invoices for now.

On dual funding, we have found an issue with how interactive-tx is used (actually more of an issue for splicing, but we believe we should fix it for dual funding as well). The issue is described here, and I'd like feedback from other implementers on this before we merge the dual funding PR, as I think it would improve dual funding (in a backwards-incompatible way) if we fix this.

[Roasbeef]

Won't be able to attend due to a conflict, so here're some updates on my end:

• The last PR in the taproot saga for lnd is up. This covers all the on-chain logic (HTLC redemption, breaches, second level handling, etc). From here on we'll be adding more unit and integration tests, to increase confidence in all the new code.
  • I need to update the spec in response to comments, and also add in those script changes mentioned a few meetings ago (my PR above was pinned to the spec snapshot so I could have a static target).
  • We're still in a waiting-for-interop holding pattern.
• We've started to explore the design space for "Gossip 1.5" (gateway drug to PLTCs, needed so taproot chans can be advertised. @ellemouton has posted a public spec draft here: https://github.com/ellemouton/bolts/pull/2/files -- mostly in place, but a few open questions and other things to be filled in.
  • The most immediate effect here is that we need yet-another-set-of-nonces to be able to sign the announcement_signatures_2 message. Open question here is: where should we piggy back this? In the normal chan open message, or later in funding_locked/chanel_ready?
• We've done more exploration re a dynamic commitments carve out to aide in upgrade to taproot chans, but no concrete updates here beyond the existing draft spec PR (tho that only does params like max_htlc and needs to be updated to handle the new off-chain layer of indirection to go from segwit v0 to v1).

[carlaKC]

Transcript: bitcointranscripts/bitcointranscripts#236