Lightning Specification Meeting 2022/12/19

[t-bast]

The meeting will take place on Monday 2022/12/19 at 7pm UTC (5:30am Adelaide time) on Libera Chat IRC #lightning-dev. It is open to the public.

A video link is available for higher bandwidth communication: https://meet.jit.si/Lightning-Spec-Meeting

Recently Updated Proposals

This section contains changes that have been opened or updated recently and need feedback from the meeting participants.

• Dual funding interactive-tx: Add dual-funding flow, using the interactive tx protocol (feature 28/29) #851
• Route blinding Route Blinding (Feature 24/25) #765
• Add dust exposure threshold Add a max_dust_htlc_exposure_msat #919
• Fat errors Attributable errors (feature 36/37) #1044
• Anchor outputs zero fee htlc txs test vectors Add test vectors for option_anchors_zero_fee_htlc_tx #1018

Stale Proposals

This section contains pending changes that may not need feedback from the meeting participants, unless someone explicitly asks for it during the meeting. These changes are usually waiting for implementation work to happen to drive more feedback.

• Onion messages BOLT 7: Onion message support (features 38/39) #759
• Offers Offers #798
• Taproot extension-bolt: simple taproot channels (feature 80/81) #995
• Closing fee range turn-based protocol option_closing_rejected: turn-based fee_range coop close (feature 60/61) #1016
• Update static channel parameters zzz-extension-bolt: dynamic commitments #1026
• Sign commitments at various feerates Add option to sign commitments at various feerates (FEAT 32/33) #1036
• Liquidity ads option_will_fund: liquidity ads #878

Waiting for interop

This section contains changes that have been conceptually ACKed and are waiting for at least two implementations to fully interoperate.
They most likely don't need to be covered during the meeting, unless someone asks for updates.

• Tlv stream in onion failures TLV failure message and length relaxation #1021 -> implemented in lnd and eclair, needs interop test
• Fix channel pruning behavior -> fixed in eclair, lnd was already fixed, what about ldk and cln?
• Don't force close until error is received after channel_reestablish Nodes shouldn't publish their commitment when receiving outdated channel_reestablish #934
• Graph dump on gossip_timestamp_filter Inconsistent behavior around graph dump on gossip_timestamp_filter. #980
• Websocket transport websocket address type: allow transport over RFC6455 #891

Long Term Updates

This section contains long-term changes that need review, but require a substantial implementation effort.

• Channel jamming draft: Staking Credentials token issuance/redemption #1043
• Pinning attacks as related to splicing / dynamic commitments: https://lists.linuxfoundation.org/pipermail/lightning-dev/2022-August/003665.html
• Quiescence BOLT 2: quiescence protocol (feature 34/35) option_quiesce #869
• Splicing Splice draft (feature 62/63) #863
• Simplified commitment Feature 106/107: option_simplified_update. #867
• Hold htlcs before forwarding Add the ability to hold HTLCs before forwarding (FEAT 52/53) #989
• Trampoline routing Trampoline Routing (2021 edition) (Feature 56/57) #829 and Trampoline onion format (Feature 56/57) #836
• Peer storage backup Peer backup storage (feature 40/41/42/43) #881
• Anonymous gossip
• lnprototest (https://github.com/rustyrussell/lnprototest)

[TheBlueMatt]

Should we push this until after the holidays? I'll be working monday but I assume others may not.

[t-bast]

Right, if most people are on holidays let's push this one to January. I'll be around just in case @niftynei or @rustyrussell are around because there's a couple things I'd like to discuss with them, but no pressure, if not let's just skip this.

[rustyrussell]

@niftynei and I are actually on the call RN, @t-bast

[t-bast]

Meeting nodes regarding the dual funding PR:

• feature dependency on option_static_remotekey will be removed
• we will remove the recently introduced est_witness_weight
• the second_per_commitment_point was added to open_channel2, needs to be added to accept_channel2
• we simply ignore its duplicated value in channel_ready for simplicity (may reuse that field for something else in the long term future)

Meeting nodes regarding route blinding:

• good progress has been made, nothing major to report
• minor issues are being worked on in Blinded paths cross-compatibility issues ElementsProject/lightning#5823