The Future of Lightning

Reading

Content	Time (min)
Breaking Down the Bitcoin Lightning Network: eltoo	15
Eltoo by fiatjaf	15
(optional) Eltoo and the Far Future	40
(optional) Eltoo whitepaper	60
(optional) Onion Messages	X
AMP/Offers/LNURL	30
Submarine Swaps	15
Splicing	30
Splices and Liquidity in the Lightning Network	15
Dual funded channels (until min 26)	26
Liquidity Advertisements	15
Multi-party channels/Channel factories	20
Payment Points: Replacing HTLCs	15
Payment Points: "Stuckless" Payments	15
Peer Backups	10
Asynchronous payments	10
(optional) LSPs	10
(optional) Gossip v2	15

Discussion Questions

Breaking Down the Bitcoin Lightning Network: eltoo

1. Why do we need SIGHASH_ANYPREVOUT for eltoo?

2. What do HTLCs look like for an Eltoo channel?

Eltoo and the Far Future

1. How does a cooperative close work with Eltoo?

2. Can channels using Eltoo or PTLC be mixed with standard channels in a multi-hop payment?

3. Since all update transactions have the same shape, what's stopping earlier update txs from binding to later txs resetting to an old state?

4. Why do settlement txs also need SIGHASH_ANYPREVOUT?

5. Would there ever be a reason to prefer LN-penalty when creating a channel between two Eltoo-capable nodes?

Submarine swaps

1. Can an adversary make a swap and then wait until a moment before the lock expiry to reveal the secret on one chain while using the signature on the other? If the blocks are fast, could an attacker be able to steal the money from both chains?

Splicing

1. Is it easier to splice on an Eltoo channel?

Multi-party channels/Channel factories

1. What are the advantages and disadvantages of multiparty channels?

Dual funded channels

1. How do you split the fees in dual-funded channels?

Payment Points: Replacing HTLCs

1. How does a wormhole attack work?

2. Can sender or receiver notice a wormhole attack?