Rene Pickhardt lately kicked off a thread discussing the variations between two celebration and multiparty (greater than two members) fee channels because it pertains to his analysis work round fee reliability on the Lightning Community. He voices a rising skepticism of the viability of that route for growth.
The excessive stage concept of why channel factories enhance the reliability of funds comes all the way down to liquidity allocation. In a community of solely two celebration channels, customers must make zero sum selections on the place to allocate their liquidity. This has a systemic impact on the general success charge of funds throughout the community, if folks put their liquidity someplace it isn’t wanted to course of funds as an alternative of the place it’s, funds will fail because the liquidity in locations folks want is used up (till it’s rebalanced). This dynamic is solely one of many design constraints of the Lightning Community identified from the very starting, and why analysis like Rene’s is extremely essential for making the protocol/community work in the long term.
In a mannequin of multiparty channels, customers can allocate liquidity into massive teams and easily “sub-allocate” it off-chain wherever it is smart to within the second. Which means that even when a node operator has made a poor determination wherein individual to allocate liquidity to, so long as that individual is in the identical multiparty channel with folks that might be a great peer, they’ll reallocate that poorly positioned liquidity from one to the opposite off-chain with out incurring on-chain prices.
This works as a result of the idea of a multiparty channel is actually simply everybody within the group stacking typical two celebration channels on prime of the multiparty one. By updating the multiparty channel on the root, the 2 celebration channels on prime might be modified, opened, closed, and many others. whereas staying off-chain. The issue Rene is elevating is the price of going on-chain when folks don’t cooperate.
The complete logic of Lightning relies round the concept in case your single channel counterparty stops cooperating or responding, you may merely submit transactions on chain to implement management over your funds. When you could have a multiparty channel, every “stage” within the stack of channels provides extra transactions that should be submitted to the blockchain with a purpose to implement the present state, which means that in a excessive charge setting multiparty channels will likely be costlier than two celebration channels to implement on-chain.
These are core trade-offs to contemplate when these techniques in contrast to one another, however I feel focusing solely on the on-chain footprint ignores the extra essential level relating to off-chain techniques: they’re all about incentivizing members to not go on-chain.
Correctly structuring a multiparty channel, i.e. the way you set up the channels stacked on prime, can help you pack teams of individuals into subsections which have a status for prime reliability, or who belief one another. This is able to enable folks in these subgroups to nonetheless reorganize liquidity inside that subgroup even when folks exterior of it are usually not responsive quickly, or go offline as a consequence of technical points. The on-chain price of imposing issues, whereas essential, is sort of tangential to the core design objective of an off-chain system: giving folks a cause to remain off-chain and cooperate, and eradicating causes for folks to not cooperate and power issues onc-chain.
It’s essential to not lose sight of that core design facet of those techniques when contemplating what their future will appear to be.
