ETHKL#5 - Part3: Andras Kristof (Akomba Labs) and Lai Ying Tong (Ethereum Foundation)

[Music] this will be unregistered from combat labs and like in town from eternal foundation interesting thing to note Tom I'd like to ask you discussion later but independent of how being from a physics graduate from yield and us end up being a researcher for in foundation and and rest for those of you who may know Dave undressing they've started unrest started tempest to engineering a long long time ago before a theory was even started now I was on Stella so these are two of the oldest in experience we don't worry you can I get hi everyone thanks for coming down on a Friday I am in town from a theorem foundation this is an judge from a combi and we're bringing to you fresh from Def Con for a theorem scaling solutions so right so this is a summary slide if you're gonna take pictures take it up this light of where we're at right now in the landscape of scaling solutions so we have layer one solutions which involve protocol changes which will involve a hard fork of the a theorem blockchain we have layer two solutions which basically move state op chain so it can be implemented right now without a heart Fork we have succinct proofs which can cover previously which will elaborate on later on it's a interesting scaling solution and on top of that we have more integrations such as storm light clients client optimization so without further ado layer one so we've been working with many customers in the law to three-year serve or material and it turns out that everybody who runs an actual business and try to use book chain will need some kind of skimming solution so very interested in what kind of solutions because stealing solutions we can expect to see later on sanity is the is the proof of state solution that we have been waiting for for it but it is it is coming it is combined in quite a few solutions the main the layered one to scale one of them is a spoof of state which is which is going to be the beacon chain it is less known that good was a itself is going to be a sort of a stable solution because of for group proof of work to to work you you there must be a certain amount of time between books for proof of state there is no such there is no such requirement to stay to debate a certain amount of time so the proof of state that the time it in the blocks is only defined by the ability of the network to to propagate the new goals so as a side effect but switching to proof of state will provide a certain amount of skill as well but most of the scaling at least one from the later one will come from from Charlie we should not be going to very deep into it but after the panel if you have questions we will try our very best to understand it together with us basically what will what will happen is that shouts will will operate as separate chains but they are all going to be coordinated together with the bigger chain and because of that technically we can we can we can have I believe the original idea is to have like one of the charts the beginning and so it means if if we can have like one book every four seconds I think they are what they want for sake right the specs keep changing that yeah faster faster faster okay let's say five seconds so instead of one book every cycle we can have 100 books every 5 seconds which which sounds very very reasonable and very nice the big problem is how to make sure that the different charts will work together and they start going to the different states won't be able to want the adaptable one interesting thing is as you can see that we have still a proof-of-work team on top of the whole team which is which is technically still the maintaining and even when sanity comes out the proof-of-work team will stay there the blood is according to according to us from from from that corner that when the forty is deployed the decon team will be the actual actual maintain and their and the old how do we call it the old may change the proof of your team will be migrated with all the states that happen until now into one of the sharks and that time there will be no poverty anymore and we will have the bigger change as the ostomy chain so it's going to be a very exciting process and I do think it's going to take some time it will hopefully make a universe where not every note has to down up the flow blockchain but only download a shark and then you know we can we can trust that these charts are and first of all across the whole network because we rely on the beacon chain of validators who are state who have a stake in ensuring the security of the system so that's layer one and that's all happening on a protocol layer and a consensus layer where ice layer two solutions of different because we are working with other limitations of the base protocol and shifting basically as much of our operations off chain as possible you guys might be familiar with payment channels have you guys heard of the Lightning Network and bitcoin yeah so payment channels if you guys are familiar basically only involved two Unchained transactions one to open a channel one to close it and so here you can see Ellis opening the channel with the five Bitcoin deposit that little clock there means that it's time locked so she'll get a refund if nothing happens after the tough after that amount of time so she opens this channel then she takes it off chain with Bob and you can see her she transfers Bob first one Bitcoin then two bitcoins and these transactions it's crucial to note have to be signed by both Alice and Bob and once you get a signature of everyone involved in this channel you can consider this transaction this state final so you call that instant finality meaning that anyone can exit it on to bet on chain at any time which Bob does now he exits the state and with the payment channel there is a challenge period so for instance if Bob decides to well no I guess it's Ellis decides to exit this state where she has a bit more money still Bob can in the challenge here at Stephan with the later state that was signed by Alice as well and so get his rightful to Bitcoin you guys are familiar with the Lightning Network basically making up a whole system of payment channels so that Ellis can sim send something to Eric without directly opening up a payment with him and this is done using hash timeout contracts but basically Eric sends the hash of a secret to Ellis before setting up this chain of transactions such that every transaction along the way can only be claimed by someone with the preimage of the hash now state channels are simply a generalization of payment channels so in these channels you can do things besides transactions you can play tic-tac-toe even play chess or whatever you want so but the mechanism is still the same underneath the thing is with state channels that people have realized if you keep making application-specific state channels then basically you're gonna deploy a new state channel for every new game you want to play like one for chess one for tic-tac-toe and that can come up to quite a few Unchained transactions as well so a bunch of people at this good cut elf for actually came up with a generalized state channel solution called counterfactual so what they do is they abstract the logic of whatever your channel is supposed to do into a counterfactual contract and here a counterfactual a counterfactual event means something that could be true but isn't so in this case it's a smart contract that could be deployed on the blockchain at any time but isn't so that's why it's cheap and yet it's still secure because if anyone wanted to exit the contract state they could yeah so yeah the thing about payment channels and state channels as you may have realized it does require everyone involved to sign off so that limits the pool of participants to reasonably small and reason we trust it and also once the channel is closed it's closed everyone is to enter and leave at the exact same time so that makes it okay for a few use cases but people have been turning the site change as a more general solution so this should look familiar to you guys it's also someone entering a sidechain by basically making a deposit on the main chain and then making a transaction off chain and then exiting back onto the main chain but you notice here that just because Bop accident doesn't mean the whole site chain has to close down and also Bob didn't have to wait for everyone to sign off on something before exiting the only thing about site chains is that you have to trust in the operator because the operator could actually the operator could actually do all sorts of funny things like for instance let's say yeah let's say Ellis deposit some money here and she transfers it to Bob but the operator chooses to censor this transaction not include it and instead the operator creates a transaction out of nowhere to himself and submits that back to the main chain thus draining this contract here of Alice's original deposit and then if afterwards the operator includes the legitimate transaction and Bob tries to then exited the contract has already been drained so to get around that people have come up with a set of solutions called plasma the basic rate plasma you can think of it as us oh there's a lack you can think of plasma as side chains with security guarantees so over here I've listed three plasma implementations that are common the thing is there is no one true plasma people have different flavors of plasma that are appropriate for different use cases but they all have a few things in common so basically you can choose any contents as you won the plot purposes to create the blocks this is not familiar cuz it's the same thing in the sidechain the thing that's different than the sidechain is that plasma men dates that the operator must really block headers back to the main chain and this is so that users of the plasma chain are guaranteed the ability to exit whenever they want and the ability to make rock proofs in case the operator misbehaves so I will quickly take you through some of the very common plasma designs so duh yeah the og plus malleolus plus nice plasma MVP Minimum Viable plasma and shortly after there's some more enviable plasma that came out so MVP and more VP are based on unspent transaction outputs and they use a data structure called the binary merkel chain we're gonna go into that so basically yeah this is a mistake to put all this text on here but plasma MVP and more VP give you some guarantees some security guarantees about your ability to exit the plasma chain and gain back the original deposit that you put in it so for regular that's it how they guarantee this is the order exits by the priority of your oldest output yes of your oldest output so that if the operator in and invalid output in a sudden block as long as your output came before his you'll be able to exit with a higher priority so you'll be able to exit before the operator can drain the contract but what if the operator doesn't include your check your output at all so you can't prove that your output has is older than his because your output wasn't included at all so that's why I'm more vp comes in this is an animation from a group called musical that they basically order your exits by the age of your youngest input so it doesn't matter if your exit wasn't included as long as it references an input that is older than the invalid then the invalid transactions input you'll still be able to exit it I know it's a lot of people can talk more about it during the panel and a very different flavor of plasma is plasma - so MVP and more making up based on unspent transaction output so this makes them suitable for fungible tokens like ether like Bitcoin whereas plasma cash is based on non fungible tokens so you can put things like you know juice crypto kitties yeah and this actually is really nice because it allows us to reduce the amount of data checking necessary per user test now you're only interested in your own claim and you can distinguish your own coin from other people's coins as a unique token ID and so you only need to keep track of your own merkel brunch whenever you're trying to make a fraud proof or trying to make an exit yeah on top of plasma cash there have been certain strategies to try and defragment these non tangible tokens so to try and get them as close to fungible as possible so one of these is plasma debit where basically everyone opens a payment channel with an operator and it's allowed to withdraw or debit arbitrary denominations from this payment channel yep so that that was layered and it's nice and starts I actually don't think I'll go through in detail because can already did so but you can think of it as basically stuffing all the things that you want to prove into a very succinct form so that you don't need to say really a chunky data structure you just need to basically send a constant size proof or a smaller proof and the T and start stands for transparent starts do not require a trust that setup unlike snarks so there have been companies like start where who are looking at the ZK starts although it's not as developed as snart's which we we know as being using Z cache already so basically the between the starts Knox and the stars stars so that makes it much less usable for music where every bit counts but there is a lot of energy research when this starts and the group size is very dark and I do believe that soon we can actually start six of our stocks alright pour into business and more more more ways to make the chains faster smart who knows about war it's basically idea fissile material it helps because in this way you don't have to store all these expensive you can store it from the side and you can just include the hashes yes good idea [Music] I need to do something light diodes in the same way it is kind of a pseudo pseudo stealing solution but scanning solution the way that you can run a client that you can you can operate the book a video having to having to sink the whole team which is pretty much impossible these days and so like mine scan can happen very recent announcement that they want to make mask into a bike lane that also seats data and it has a very very weird name I cannot remember but thank you and the Moscow Pisa is an octopus or something like that so it is very interesting and and basically what they are building with that is like sharp daylight at least we understood it it's very interesting don't say and light optimizations helps in in again so many ways because with this one we can run the same class like again but it will take less progress less hard this space and in general next on computer class and they do seem less significant than the previous layer by layer to solutions but they are as a second way to happen that's the state of scaling on it here [Applause]