#DappCon22 : Day 1 - Communities And The Future Of Ownership, Frederik Lührs

Transcript

tell us why do we need Beamer chick chick hello can you hear me all right hey guys my name is Fred I'm the lead architect of Bima bridge and I'd like to talk to you today about why we think the future for bridging is optimistic so with a quick recap of the last bull market I think you all know we're at the D5 summer The nft Craze degence aping into protocols and it happened what must have happened ethereum started to congest Big Time the scalability issue really became pressing and what we also saw is

projects moving away from ethereum exploring Alternatives alternative layer once side chains and roll ups coming up but still imagine all those projects on different networks people want to be flexible they want to use those projects so bridges are being built between those different layers there are lots of bridges Bridge projects and here's one more but I'd like to present to you to you today why it is important to have one more um but when we started researching in this field

we realized that most of the bridges try to do it all so they try to do what we call like all-in-one Bridges bridging from layer ones to search and roll ups and that results in the bridges needing to make tradeoffs some are slow some are more expensive and some and what we have seen in the recent year lack and security so when we started working on bema we thought like okay how can we improve existing designs and before we got to the solution we really thought about like how should a bridge look like from a user's perspective so a bridge if a user wants to be wants to bridge tokens

it should basically just a one click or one transaction basically seamless seemingly transferring tokens as if it would on one network but just to another Network but at the same time we want to stick to our principles and we don't want to get this nice user experience by sacrificing security so today I'd like to use Bima Bridge which is an optimistic bridge between roll-ups and allows users to transfer tokens between roll-ups and even more the vision of bhima becoming the backbone infrastructure for roll-up intercom communication and

eventually abstracting away away the fragmentation of ethereum but step by step so bema enables transfers of erc20 assets directly between two evm compatible rollups without going by layer 1 of course leveraging optimistic architecture what that means I will to you explain to you in a second so first let's go into user experience so when we talk about user experience we really have like six key metrics where we take care of or like which we measure the quality of a user experience a bridge should be simple so users only

should complete one transaction it has to be fast so ideally as I mentioned sending your transactions receiving tokens right away of course cost effective whereby Beamer doesn't really optimize for that case but we have seen that we are around the same fees as other Bridges and at the same time we guarantee certainty so that means if you send 100 token you you receive 100 token and not those maybe you have seen it in other Bridges sketchy 18 decimals fraction of the the amount we only send canonical tokens native to

the bridge so we don't have our own lock and mint mechanism we leave that to the Roll-Ups and because we believe that the Roll-Ups do that best and have the greatest security here and at the same time and that is kind of most important point we want to guarantee the highest security possible so ideally layer One Security not adding any trust assumptions and we believe that this is necessary for becoming a backbone infrastructure transferring information from one roll up to another so how does Pima look from a user's perspective first of all Bima Bridge is a market

making protocol so it connects users who want to bridge tokens with agents which are liquidity providers wanting to provide the service for a small fee there can be multiple there can be permissionless infinite amount of Agents but how does the how do these two characters like persons connect together so a user who wants to bridge tokens will lock his tokens on a source rollup where he got the tokens include with additional some fees and the information where he wants to get like further request

as soon as an agent sees that he will directly provide the service up front on the target rollup so that means as soon as one transaction happened on the roll up of on the first roll up the the second transaction is initiated directly and at that point in time the user has received the tokens on the target roll up so that means the service was provided and the user is actually done so the user is not involved in any dispute resolution or whatsoever shall we get into in a second so to summarize the users enjoy a near instant service

but of course the agent would only do that if he can be sure that he gets his token back and that everything works according to the protocol and here we leverage optimistic architecture what you might know like how optimistic rollups work so the agent will go to the contract claim that he fulfilled the service and then a Time window opens and where anybody can challenge this claim or the validity of the claim if that didn't happen or if that doesn't happen the agent is able to withdraw tokens and the trade is actually settled so um note that the contract on the

source rollup doesn't know about the state of the target roll-up so he trusts basically the com the the network that nobody challenges but of course that is the happy part the happy path and we expect this to be the the common case but this only works if you have a bulletproof secure fallback mechanism so what happens if someone challenges this claim is the interesting question actually before we get into that as I mentioned bema is an optimistic Bridge roll up to roll up only we believe in the roll-up Centric future of ethereum

so we believe in the long-term projects we'll move back to Roll-Ups which live on ethereum making ethereum a global settlement layer for roll-ups and building a bridge for all roll up specifically allows us to improve on security and leverage properties of Roll-Ups namely data availability so all rollups live on ethereum and all the data are available so if you think about that that means that in theory we could validate the state of the target roll-up on ethereum layer 1 because all the data are there and then after validating that we could

forward this information to the source roller where the dispute is ongoing and then we have the real information the real data what really happened and the claim could be resolved correctly but of course we wouldn't build a bridge from roller to roll up if we had to go to Leia one every time so layer one is slow it's expensive we have to take into account finality periods of roll-ups and thus the we need we need to implement an crypto economic protocol which incentivizes the correct Behavior so incentivizing corrupt Behavior means not lying about claims basically not making invalid claims

and punishing any malicious behavior so it must for one it must be incentivized to do the correct behavior and second it must be costly to not do so so how does a protocol like this look so what if we [Music] um if we get back to the agent claiming that he fulfilled a request what I didn't tell here is that the agent also has to put in a small security stake which he is willing to lose if he's not saying the truth the stake doesn't need to be very high but

it must be enough for incentivizing people to step in and challenge invalid claims so let's continue with the case that someone challenges and he also puts in a small security stake so now we have a dispute for an ongoing claim the contract itself doesn't know if it's valid or if it's if it's invalid and we know at one point we could go to L1 and resolve that but that's very costly and that's why we introduced an escalation game mechanism so once a claim is challenged we enter into a challenge period which will last for a while and in in which the claimer and the Challenger can

outbit each other so um it's you can imagine it's a bit like a poker game putting in higher stakes and higher stakes and the the winner will get the whole Stakes the whole stake eventually so now the question is how does anyone can win this challenge so there are two possible ways one one of the parties steps stop stops engaging into the protocol and the challenge period expires then the highest stake wins so it might be the case that someone realizes okay I'm not getting getting away with it I'm losing too much money so I stopped engaging in the protocol but that wouldn't be very secure so at

this at the second point in time you as I mentioned you can always go to layer one execute the the L1 what we call the L1 resolution and we have the real information what really happens and resolve the claim directly why do we have an escalation game in the middle that is specifically there to enforce that the malicious party will pay for the L1 transaction so the the honest participant was simply Out start outbidding the opponent until the opponent the malicious actor has put an enough stake to just go uh to just say like okay oh no there are enough funds by the malicious actor so for me

it's fine to go to L1 pay for a more costly transaction and get all the stacks so getting a little bit more into detail to that here is a user flow diagram of the honest participant so imagine here in the beginning well sorry here in the beginning we are the honest participant and we are leading currently in the challenge so we have the highest tax then we will simply check um did The Challenge end then of course the the dispute is resolved correctly because it's an honest participant if not he will check if he got challenged if you didn't get challenged just wait and repeat

if he got challenged then he would simply check oh did the opponent put enough stake into this challenge so that it's enough for me to go to layer one and resolve it correctly if not outbit him and repeat and if at one point there is enough stake in there then the honest participant can simply go to layer One Transport like forward the real information from the target roller to the source roll up and the claim again will be resolved correctly so looking at this if there is one honest participant who follows this protocol any claim will always be resolved correctly and this is due to the fact that we have the possibility to validate

the state on layer one so getting the security of layer 1 into the protocol so we really thought a lot about how we can make that very secure and it is so secure that we really think that it is going to be rarely executed because it economically it doesn't make any sense to engage in this protocol um and misbehave yeah that's already it um as a summary uh due to the fact of an optimistic design of our bridge and layer One Security we are able to bring a near instant bridging service for users this system is permissionless that means

anybody can step in and challenge so basically we have an infinite number of Channel and potential Challengers and we built a dab the Beamer dab which is a one-click interface to allow uncomplicated transfers from a roll-up to to a roll up we are live on testnet since March and we are very very close to get on mainnet so please follow us stay updated stay in the loop follow us on Twitter um this QR code is a link to our testnet testnet.beamabridge.com uh check it out try it out we have a faucet there and um yeah thank you very much

questions thank you Frederick this is looking awesome is there a demo um on there right on there but we could plug in any laptop and go to testnet.com but you can also try it yourself okay there you go try try it at home that's the advice so any questions uh with uh with layer to use support because I think that if you connect this to a different ebms maybe if you connect to roll ups every lab has his maybe estate three how it how it works inside and maybe the fraud proof should be

different right yeah yeah that that's true so um we have some requirements the the basically the theoretical main requirement is that state is available on ethereum layer one currently we are supporting all optimism based Roll-Ups so that is optimism Boba it used to be meters meters changed from being a roll-up and we are also very close to integrating arbitrum it helps definitely what we what we basically use is the messaging layers of Roll-Ups so it helps definitely if there's a messaging layer available but it wouldn't be a deal breaker because we the only thing we need is like a way to

validate the state on layer one thank you so you have a fraud proof for every different role right thank you hello hello so if I understood correctly uh in the dispute uh between the honest and the malicious party um what happens if the agent does not have the honest tangent does not have enough you know money to outbeat the demolitions how do you prevent that from from happening and losing yeah so that's a very good question um

the only requirement we have for the agent is that he should have enough ease to pay for the L1 transaction that means he will not pay for it but this is the amount of if he would need to put into the challenge game so that the malicious actor needs to outbit him because outbetting means like putting in an even higher stake right so let's say if just some example if the L1 resolution costs a hundred dollars then if the agent is able to put in a hundred dollars then he will definitely win the challenge and does not pay for the L1

transaction because either the malicious party will not engage anymore so it will simply expire or the malicious party will submit an even higher stake and then resolving on L1 will result in a profit actually so you constantly monitor the agents to see that they complain with this sorry so you constantly monitor the agents to say that they have enough funds to do that yeah so in theory agents should monitor themselves because um we are not controlling the agents this is an open protocol but any agent should be sure but maybe to to extend on that a bit

not only agents are able to challenge it could be even anybody so if you see that someone put in the invalid claim you could even go there and challenge so you don't need to be an agent for that thank you very much you're welcome it's one question over here uh just a quick one you said if you put in just say you put in a hundred dollars and you transfer you get a hundred dollars um how much fees does a liquidity providers make because presumably they would want something yeah yeah sure so um we Aim so fees are in in theory um flexible to the age up to the agent but currently we aim for a 10 to 12 apy

for the agent so um once we get mainnet real mainnet data we will dynamically adjust the fees so that it results in around that range so typically what we currently have is a 0.3 percent of the transfer volume with a minimum value if you do lower values of course thank you one more we have room four one more over here hi Friedrich so I wonder there are so there have been so many hacks for different kind of bridge what are the things that you guys do differently to

prevent that kind of hacks yeah that's that's a good question and we actually started building Bima before all those hacks happened but it's it's a really um uh yeah prominent and imminent issue so um in our protocol there are no tokens locked in a contract per se where you could provide passive liquidity or something like that so it is always up to the agent how to manage its own funds so basically the agent itself is controlling its own funds in its own wallet and yeah you would really need to like hack a server or something like wherever the key lies but of course um we cannot prevent if someone gets his

Keystone then uh um no one can prevent from taking on the funds out of it I think there was last question yeah okay two two last questions go ahead um what if two agents send send the user funds like competing for it yeah how do you resolve that yeah a good question um so the agent sends the tokens directly to the user but he does it through a contract and the contract prevents execution of two fulfillments for one request basically oh

there was one over there um so each agent they have to put a security deposit is this based on the amount the user has to bridge so for example if I want to bridge 10 million dollars is the agent going to put 50 so it's good to put a percentage of the amount that I'm going to break as the you mean as the security deposit during the claim yes yeah so um in it is not bound to the amount he Bridges because the agent upfronts it anyway so um so basically it's it's in his best interest to actually uh get the money

back and do a valid claim um of course there are some interesting uh behaviors but potential like potential behaviors which we need to figure out but uh like there is a Optimum value and it should be low enough so that it is it is opportunity cost for the agent right so it should be low enough so that is the opportunity cost is not very high for him but it should not it should be high enough for anybody to be incentivized to challenge if this is an valid claim so and then that is basically the two forces who um yeah yeah that was the direction of the question like mainly you know if you rely on a single honest validator if the

opportunity cost is I'm earning 10 million dollars or a hundred dollars for making a claim then it's obvious that we are going to like partner up split 50 50. yeah but but there's like um maybe then I didn't get your question so what would you partner up for yeah so um there will be like a network of Agents right that they will presumably be at least one honest agent however if the opportunity cost is very high in terms of I can be honest and earn as long as a small amount or we can like cartel together and earn millions of dollars

for a single uh commit I mean yeah so earnings should be impossible because like what you only need is like one honest agent who's able to um to challenge the invalid claim right and challenging is permissionless so anybody can do that it doesn't need to be an agent I mean even you and I can do it so in theory um and there's like incentivization for it you you will make at least 100 profit on on challenging it in and so in theory anybody can do it so there's an infinite amount potentially there to to challenge invalid claims

thank you thank you so much thank you a round of applause I think this is awesome thank you very much Frederick