 Thank you guys couple that come for this talk when I want to present about today is what we've been building for the past six months a Financially accountable watching network and this is in collaboration with Chris who's in the audience Surgery and Salvatore right what what I really want to highlight is that normally when people think of Pisa They think of off-chain protocols and scalability So I've actually taken this moment where this talk is not going to have anything to do of off-chain protocols whatsoever I'm going to highlight how Pisa is generally useful for most up developers cool Now what I'm going to begin with is actually a watching network. It's a misnomer There's actually two different rules in this third-party broadcasting network. We have relays We are meta transactions You know you give a transaction to this third party and they guarantee that it gets relayed to the network or You have watchers You know these watch towers and a watch towers You can be hired simply the watch for events on the blockchain if there's an event it will then respond on your behalf So that's why it's actually a third-party broadcast network which sounds really boring. You know lol, but that's actually what it is So why do we have you know relayers and responders? Relayers try to solve the problem when the user doesn't have access to the native token So this could be onboarding new users accessing coins in a contract like a multi-seg or Mixing and tumbling as well Where watch towers and responders they try to alleviate the user liveness requirement That's to say you do an auction, you know, you submit your bid three days later You have to reveal your bid and we don't want to come online in three days time So the watch tokens is do that in your behalf Of course the main motivations always been off-chain protocols like plasma and state channels And you can also do data availability providers as well So what is the perception of a third-party broadcasting network, you know, how did people typically think about it in their protocols? We're first you have a user and this is the anime edition by the way of the talk So the user typically has a job And what they're going to do is hire multiple watch towers at exactly the same time So they're going to send the job out, you know, bam, bam, bam, and then multiple watch towers now have the job but The user has to pay for multiple watch towers. So this sounds a bit crazy expensive, doesn't it? So typically what people do instead is that there's this on-chain bounty So the first watch tower the saw, you know, the relay the transaction and get it in the blockchain We'll get the claim this bounty So can you see the obvious problem with this if you've hired 20 watch towers on they're all competing for the CM bounty You're going to get spam spam spam spam spam You know only one watch tower is going to get rewarded and the rest are going to have to pay a penalty You know the God's price of a transaction for failing to get it in and that's not very good You know as an illustrated example bomb, you know the reward is given in this watch tower Now if they're competing for this 5k, you know, $5,000 is a bounty That's fine over the long period you make some losses you win, but if they're competing for $5 That's a sucks, you know, who wants to compete for $5 and lose money in the long run So it's not a great way to build these third-party watching networks An alternative approach with people 10 that recommend is why don't we you know do segments? So what's tower one can respond by time t1 what's tower two can respond by t2 up to tn Now the issue here is that is really awkward to enforce either your smart contract considered as upfront or You somehow try to enforce is an off-chain monitor, which doesn't really work either So I've never really considered this as a real valid solution to the problem And then the worst case scenario You guys hired 20 watchers and nobody responded and your transaction was never relayed Maybe you lost the auction you lost money in your state channel Well, there's no evidence. There's no recourse nothing So I really sucks this from a user perspective. You can't blame anyone because they didn't do their job So why do we always think this is the best way to build this third-party broadcast network? It was actually really frustrating because it's clearly awkward and it doesn't work that well You know, I've got my little anime gift there So from the end user perspective Why are we trying to design these third-party relay networks in this fashion? So what are the goals that we're trying to achieve? Typically we're trying to minimize trust We don't want to blindly trust a single party to respond in our behalf and also for the availability of broadcasters If I hire 22 watchers Hopefully one's the least online to complete the job for me But what most people seem to forget about is accountability You know, if the watch tower doesn't do the job for me, can I prove that and can I hold them accountable? So this is basically what we're building a pizza a Financially accountable third-party broadcasting network. So now I'm going to start my talk cool So what is pizza? Basically, we have this broadcaster. He has skin in the game and coins locked up on the blockchain And there's a pizza contract which is effectively the service level agreement between the tower and the customer Now when the customer hires pizza you send the job the pizza and in return the customer would get a signed receipt So now they have, you know cryptographic evidence that they've actually hired pizza or a watch tower So what type of job can pizza accept? Both it can be a relayer, you know these meta transactions and it can be a responder It can watch for events and respond in your behalf And of course the way it would look like is you know Alice and Bob do something Alice hires pizza. Alice goes offline If there's an event on the blockchain then pizza will simply respond in Alice's behalf Then Alice can come back online later, and then she can you know verify that peas in the watch tower actually did his job Now the question is What a piece of didn't respond What a piece of didn't do the job and didn't protect the customer, you know when it when it promised it would Can we do anything about that and that's exactly what peas is trying to solve Pisa is a trust minimized, you know third-party broadcaster because it has financial liability The user has a signed receipt that they hired this watcher and they have on-chain evidence that Pisa didn't do his job You simply submit both pieces of evidence to the Pisa contract Whoops, then the Pisa contract will look at the evidence evaluate it and say yep Pisa didn't do his job So now it forces his refund period and there's two outcomes either Alice is refunded a pre-agreed amount That was you know specified in the signed receipt or Pisa is eventually sloshed So Pisa issues the refund really straightforward. You send the money, you know that challenge is cancelled and everyone's happy So I've got one question here. Who's ever send a transaction to the network that lingered for six hours There we go. Look at the you're all dub developers definitely now What would be nice is if it lingers for six hours, you're gonna get a $20 refund from Pisa You know, so you're gonna have a little smile on your face because you made money for that for the bad UX user experience Anyway, if Pisa doesn't give you that $20 refund Well, you know blocks keep ticking Pisa gets slashed and Pisa will lose his money and be very upset And that's the basic principle about you know behind this Now what does this on-chain evidence actually look like? Well first, let's look at the relay case these meta transactions every time you hire Pisa the relay a transaction in your behalf Pisa will relay that via the Pisa contract and it simply keeps a record of every attempt Okay now Yeah So it keeps a record of that attempt. So later on if you come online, you know Pisa promised you this transaction Would be relayed before time t you come online after time t you look at the Pisa contract And there's no record of the attempt if there's no record of the attempt Pisa didn't do his job You just send over the signed receipt and Pisa gets punished. So that's cool That actually works out of the box today On the other hand, what about the responder? Well in the case of the responder Basically, we have to look for events in the other contract. So let's consider the auction We have to watch out for you know the auction to be triggered Sorry, yeah, we have the watch out for the auction to be triggered Once it's been triggered then there's evidence the auction was triggered and that we didn't respond Now the issue is that? This can't work today But it requires its external contract to use our data registry and that's not great. It's a bit invasive We want to make sure we have seamless integrations to Pisa So for seamless integrations, we have to push for this hard fork for blocked up block harsh If we have this, you know hard fork then we can use the transaction receipts in a block as evidence that Pisa didn't do His job if you want to learn more information about that just check out this wonderful blog post that Chris wrote Oh, and I also found this emoji. I'll try to find a fork emoji So if you want to get this in the iOS, you know sign up to the change org So what's the currency of the Pisa project? You know, this is something we've been working on for two years in terms of designing the protocol And now we've been trying to implement it for the past six months What's nice is that we envision it to be like an inferior like API as Adaptive developer you're simply gonna have a very simple API like this you tell Pisa when do you need that transaction delivered? What was the call data and what is the contract address? You simply call the API and in return you'll get assigned receipt and that's awesome And right now our current guinea pigs are connects and L4 So now we're actually trying to do an integration to see how well this works And once it works everyone here can try it out And of course if you want to find more information about it our client information is on and you know MP MP JS and everything's open source So you can just look at this repo and you can see exactly how Pisa works today, you know and try it locally amongst yourselves Now as Pisa a boring tedious and hard project Actually Pisa is a high availability Reliability and fault-tolerant project What do I mean by that? So if you're a dub developer and You got to guarantee transactions for your users get in the blockchain What you've got to worry about is bumping the feed during congestion You've got to worry about managing the balance of multiple hotwalls to pay for gas Managing dependent and chain transactions handling block reorgs and hard forks Detecting these emitted events taking data from it and using that as part of the response And one really good example of this was defi saver You know if you combine if you pick two or more of the above it becomes non-trivial so defi Siaver had a chain transaction, but in the chain the first transaction had a low fee It had a low fee and it didn't get in which meant the other transactions also didn't get in So this is actually a non-trivial problem to build and actually most projects have to do this Which sort of sucks it's taking us four or five months to get an alpha version that we're sort of comfortable with If we expected you know every team to replicate this you've already lost four or five months of engineering time So that's exactly why I think Pisa is useful for most dub developers And what about the future of Pisa? What I really want to build is a watching pool Okay, so typically when people think about these watching networks every all the watchers are in competition We're actually you could have a pool. We have this non-trusted coordinator You know I send the job to the Pisa server the Pisa server will send the job to each watcher If we get care to van watchers are green we get a fully signed receipt then the sign receipt goes out to the customer So actually all the watchers are watching each other's backs. So at least as you know, we know our service gets dust Hopefully one remains online. That's also the motivation for n-label programming. They avoid critical bugs Now what about the security clutter lock up a lot of people asking about this Now one of the main criticisms of Pisa is that we may have the lock up 50k dollars They're really sure that we have skin in the game What's nice is that we can outsource that other people can donate the money on our behalf and they're sort of betting on our Reputation that we won't get slashed and by betting on our reputation. You get a share of that revenue And we can also just lock it up a maker and compound then use that money They earn interest as well. This is actually quite nice. You know the money doesn't go to waste. There's a real store of value Now I just want to finish for my takeaway message of all of this, you know talk What makes cryptocurrency so great, you know, why are we all excited about it from my perspective? What makes cryptocurrency so great is that everything is publicly verifiable and we have a set of you know We have a decentralized set of validators unknown in the world can validate blocks in real time if you're validating a block You can you know hold the miners accountable you validate it and you accept it or you reject it if the miners cheat You just reject the block and what you're actually doing is holding the block producers Financially accountable if they produce Bob blocks, and that's really cool So I guess my motivation for the past few years and what we're trying to now build a pizza is let's bring financial accountability to every single online service Starting with you know third-party broadcast networks. We're building this you know financially accountable third-party And this is what everyone in this room should be aiming towards as well. We should be building services such that They've you know the terms of the you know service level agreement or easily enforceable and verifiable We should not blindly trust third parties. We should verify everything they do and If the third parties deviate from the protocol or if they cheat we should have an ability the issue punishments You know they make sure we hold them financially accountable and that's actually what makes cryptocurrency so great You know that's the tosses real vision of why he built this entire system So that's basically the end of this talk You know our goal is to build this financially accountable third-party broadcasting network Hopefully people here realized I did not talk about off-chain protocols whatsoever. It's generally useful for most smart contracts And that's hopefully we're going to be I mean there's an alpha version running already And hopefully the API will be publicly available very soon