Wtf are based rollups and preconfs? by Jason Vranek | Devcon SEA

[Music] all right thanks for coming everyone I know it's kind of early so this is a lightning talk on based Roll-Ups and pre-ms and as you know these lightning talks are extremely quick so this isn't going to answer all of the questions it's really going to try and lay the foundation and motivation for why um different teams are working on this so I I would want to start with like what is the big motivation here um and the big goal of these based rollups really is to help solve this fragmentation issue we're starting to see in the L2 space and to restore some value capture back to the base layer so how did we get here well ethereum is always in this tricky position um the goalposts always move gas was too expensive we created this rollup Centric road map we succeeded in offloading all of this execution things got cheaper TPS increased but eth is dead so we really want to try and address some of these problems headon and the big focus of this talk is around fragmentation So currently these l2s aren't interoperable with each other they fragment liquidity they fragment users they also fragment developers you have to pick a winning ecosystem to deploy on or deploy across many which starts to spread your resources and what we're really seeing is this kind of convergence on what I'm calling intraop you have interoperability within your ecosystem but not across these ecosystems so how do we fix this fragmentation problem well one easy solution is that we just agree on one entity to sequence all of these rollups and that sounds pretty centralizing so can we do this in a way that preserves a lot of the values that we care about so enter based rollups the idea here um this is a quote from Justin's paper um the tldr here is it's a based rollup when it's sequenced by ethereum validators so in this picture on the left hand side here we have centralized sequencing the idea is you have these unordered transactions a centralized sequencer job is to order them for the rollup um these little squiggly things are the Roll-Ups at the bottom here okay as we move to the right we're increasing in decentralization and we're unlocking interoperability so with shared sequencing you have multiple parties that are all agreeing According to some leader election mechanism on who has the ability to sequence all of the rollups and as we move all the way to the right we enter this based sequencing mode the idea is that the transactions for these l2s will be sequenced directly by ethereum validators and how does this help how does this unlock interoperability the idea is that we have these right locks over L2 State when an ethereum validator is going to propose a block they have a right lock over the entire L1 block and all of the L2 blocks that are going to be included and when we have a bunch of rollups that are all agreeing to be sequenced by this validator it unlocks this ability for you to start passing messages across these rollups we don't need these Bridges we're able to do these more seamlessly so this has limitations um one of the big issues with based Roll-Ups is that they have um really 12C block times a lot of users want to come to l2s because they they care about that snapy ux those instant transactions we can always reduce the L1 block times but that's a very long arduous process that has a lot of unknowns and centralization vectors so proms this is another one of these um new terms that stands for pre- confirmations a pre-com is a commitment made by these validators um to users about doing something related to block proposals so this could mean I'm giving a guarantee to a user that I'll include their transaction when it's my turn to propose the block or I can even give a stronger guarantee like this will be the state after executing your transaction and if if I break my promise as the preuner then I can get slashed um on um various means so to kind of wrap this up like how does this all come together so the user over here would be able to send their rollup transactions to be sequenced by an ethereum validator they in response give back this pre-confirmation signature um which is like this receipt for the users guaranteeing that their transaction will be in included or it'll be executed um inside of the rollup and if the validator does break this promise they can be slashed by submitting evidence to the slashing contract and what does this enable well it solves a lot of these ux problems and when we start to enter this like execution prec comps we we really make it to a place where we can actually outperform um these alt l1s by giving these very instant transactions back to users and this all comes without modifications to the Bas layer so hopefully this maybe peaked people's interest on this topic um but of course in a in a five minute lightning talk that's uh there's still many many things to be explored so thank you all for [Music] joining okay yeah we have a few questions um right yeah so the the first question here how does this notion scale um if they need to validate all of the L2 transactions so this is a great question so I think there's kind of Two Two Worlds here like one is sequencing itself doesn't imply execution so it doesn't have to take on all of the load but realistically there's different implementations of these um pre-com protocols being built some of them offload this duty to um these kind of Gateway is what they're called similar to the PBS pipeline we see today um second question pre-confirmation Services seem to be the biggest layer of complexity for me um these pre-comp networks will likely require consensus is this the biggest drawback so definitely over the past year like it's been it started from this like very dark Forest unknown and over time we've started to untangle it and some of the bigger questions are now just around pricing but really you don't need an actual consensus protocol to build this um you're able to just broadcast like these messages directly to the users and if the user like doesn't get their pre-confirmation they're able to go and slash okay maybe one last question why is Spire better than puffer why is Spire better than puffer well um we're all here building based rollups so um yeah I I understand so everyone has their own vision for the best approach thank you very much so thank you please give a round of applause to our speaker