 Hello everyone. Thank you. My name is Christopher. That's my colleague Bant. We're from Brainbutt and we're here to present the Trustline's network, which is an open protocol for decentralized IOU-based currency networks. So we broke the presentation up in two parts. I will start by presenting the basic idea and the problem we're trying to solve and then Bant is going to take over and he's going to present the technical implementation, give you an overview of the system and explain how things work and where we currently are with the project. So to start off with, let's think about something for cryptocurrencies, which is truly unique concept, which is this idea of permissionless decentralized payments, everyday payments, everyday purchases for all of us. This is unique because it enables us to payments without the use of a bank account or any kind of financial intermediary to do a payment. This is something which, at least on a global scale, we haven't actually seen before. There are some problems with it, which is that it doesn't actually work. And there's kind of two really good reasons for that, first of all. The issuance of these currencies is kind of flawed because ideally we're supposed to be able to turn on a computer and run the network. And if we do that, we're rewarded with cryptocurrency for validating a block. We get some money and then we can go spend that at a grocery store for tokens. But of course that doesn't actually work because, well, mining is kind of a specialist industry. It requires special hardware and most people will never validate a block with their regular MacBook or whatever. So where does the rest of us get cryptocurrencies? Well, we buy them on exchanges. And that's kind of a problem because these exchanges, well, they give cryptocurrencies for payments a really poor usability, is that we buy them with fee at first and then we exchange them to use something that we want to use for payments. It's kind of a clumsy user experience. It's not really good for payments. So if we were to rethink this and say let's try to create a cryptocurrency that's really good for payments, ideal. I would present three arguments that it should definitely have. It should incentivize being spent. So when I have it, I should want to go spend it. It should not need to be bought with fee on exchanges. And it should still be interoperable with the Ethereum ecosystem or the cryptocurrency ecosystem because, well, that's what we want. We want to be able to use it with our favorite dApps or protocols. We want to use it to buy ERC20 tokens, whatever. One of the ways we could do this is if we took money as IOUs and implemented it on social networks and we issued it in these individual trust relationships, we use these trust relationships to make payments. We have this global payment network, which is the original ripple idea from 2004 by Ryan Fugger, not what ripple is doing nowadays, but the original one. And it's basically these individual trust relationships, which are people who know and trust each other and they issue to other credit lines. And this works pretty much how it works in the real world. For example, if you go out to a bar and you forgot your credit card, most likely one of your friends would borrow you $10 or let you pay, pay for you for the rest of the night so that you could drink beers with him. You could settle at a later point or maybe next week you pay. So if people have these relationships already, they have these credit lines, what we could do is when people issue those bilaterally between two trusting friends, they have them what we call a trust line. And this trust line consists of two different credit lines and a credit limit and a balance which indicates money was spent. So let's suppose Alice and Bob are good friends and Alice wants to pay Bob. She spends five of her $10 credit line creating an imbalance between Alice and Bob. And this IOU that Alice, IOU that Alice issues Bob is then money which was created because we have something of value which was exchanged for this IOU. This is good for Bob because Bob knows and trusts Alice and has given her this credit line allowing her to spend up to the specified credit limit. It's totally pointless to use money for this or cryptocurrency. We don't need that at all actually because people do this all the time. As I explained, people do this at bars, they don't need cryptocurrency or any kind of money for this. This is just basically how friends work. What we need money for is when we have trust problems. So if Alice wants to pay Charlie, she has this issue that Charlie does not care about her IOU because Charlie doesn't know her trust and so she's not going to accept that IOU. And then if we go back to this payment network, what we could do is we could or Alice could discover a path of connecting trust lines that would allow her to back the IOU with something or someone that Charlie would trust. So we see there is a path of connecting trust lines between Alice and Charlie and if Alice then wants to pay Charlie what Alice does is she spends five or $10 credit line with Bob and then Bob spends five of his $10 credit line with Charlie. So this solves two problems. First of all, it allows Charlie to receive a payment from someone that he can trust because he's dependent on the solvency of Bob and not of Alice. So that's good for him. It also allows Alice to pay a stranger because she can now send a payment to anyone so long as it is backed by someone who trusts that person. Of course, this only really works if Bob is actually willing to do this, but for Bob this is not really a problem because his net balance remains unchanged. So he still has $20 he can spend. I mean he has $15 in one trust line, five plus $10 credit line, and he has five remaining in the other trust line. There's a little bit of a thing missing there which is of course at some point in time Bob might his trust line might run out. There might not be a capacity left in the trust line and that leaves him with two options. Either he has to settle or he has to ask Charlie to increase the capacity of the trust line giving him a larger credit line. Neither option is really that nice, it's kind of awkward, but this is a quite powerful feature of the idea is that we can mostly avoid settling. So when we have many users on the same network we have money which flows in many directions. Sometimes you're getting paid, sometimes you are paying, sometimes you're forwarding payments in different directions. And this social approach to money helps money circulate meaning that that cancels out over time. And so for most scenarios real world settlements are unnecessary. And as you can see here what I've tried to do is illustrate how Dave making a payment to Bob cancels out the debt that Alice had with Charlie or that Bob had with Charlie from Alice's payment. So that's basically the basic idea. That's how money implemented on the social graph could work. Now the next question would be how will we access such a system? And the way that we would do that is by having an accessibility system which is a little bit superior to buying money on an exchange. So you simply just download the app, you join by creating a trust line with a friend and then you can start sending and receiving payments. That's basically it. So compared to first joining an exchange, wiring money, this is a little bit faster. The money that we could use to pay each other is issued on smart contracts. We call them currency networks. These currency networks are highly customizable. They can be nominated into virtually anything that people find valuable and beers, bitcoin, gold, enchiladas, whatever it is people like, they can trade. And to reflect the domination they can also use these, they can customize the currency network such that it reflects the domination. They can have user groups be open or closed. So for example, the Euro token network might be more open than a local economy who wishes to control exactly who can issue different trust lines. So they might have a permissioned approach to it. We can also customize rules on interest and the specific value of credit lines. Now the final piece of the puzzle is of course how can we buy ERC 20 tokens or F? And we can use this because every the mobile payment app also comes with a wallet which can hold Ethereum or ERC 20 tokens. So if Alice wants to buy some F and she has been on boarded to the trust lines network and Dave wants to sell some and they don't know or trust each other, what Dave can do is he can list some F on a decentralized exchange and if Alice likes that offer she can take it. And if there's a path with sufficient capacity the decentralized exchange will swap the F for trust line money. So Dave will now have more credit in the currency network that they're both participating in and Alice will now have an F in her wallet address. So what that solves is the dependency we have on centralized exchanges because we can provide accessibility to cryptocurrencies without the use of Fiat money. It removes the requirement to have a bank account which I personally think is quite important because we can also provide cryptocurrency and decentralized financial services for people who might not have a bank account to begin with. And finally it also allows us to purchase F with trust line money without having or to interact with any debt. So the basic idea is you should be able to get access to cryptocurrency by joining creating a trust line with a friend and then have access to the whole Ethereum ecosystem. So that's the basic idea and yeah give this to you. Hi my name is Bernd I'm one of the developers behind trust lines. Hi my name is Bernd I'm one of the developers behind trust lines and I want to give you now a brief overview about the technical implementation. So the architecture of the trust lines network will be is a three tier architecture on the core of it we have the smart contracts that handle all the logic especially the currency networks and decentralized exchanges and as the user interface we are developing a mobile app that comes with a good user experience. This is also where the private key will be and which which will assign the transactions to actually do transactions within the trust lines network. In between we have a middle layer that we call the relay service they are helper services for example for the path finding I will talk about them later. Today I don't want to talk about the mobile app I want to focus on the platform itself so we'll talk first about the smart contracts and after that I will talk a little bit more about the relay service. So the currency network contract manages all the trust lines within one currency networks that means it keeps tracks of the balances between two friends and it keeps track of all the credit limits of these two friends that gave each other. It has a logic to execute mediated transfers that means when you do a transfer within the system it will update all the balances accordingly and make sure that they will stay within the given credit limit. We want to implement existing token standards however this will not be fully possible because they are different because our currency network is IOU based so that means there will be differences for example the balance of a user can be negative and the transfer within our system needs another parameter it needs the path over which the transfer should happen so we're aiming to for developing a new standard for IOU based currency networks. Next I want to talk about the decentralized exchange contract so the trust lines network should be a will be a platform to host multiple currency networks so one challenge we need to solve there is how do we want to connect how can we connect these networks and how can we bridge gaps because if you want to do a transfer and there's either no connection or too long connection especially the beginning we want to gap this so the decentralized exchange contract can help us to solve that because it allows to buy a collateralized token on an exchange for example at ETH with trust lines money and these ETH can then be used to close gaps and to make cross currency payments. Let's look at the following example to see how this could work so if Alice wants to pay Dave in US dollar but she's only part of the euro network she can make a transaction within the euro network to buy ETH on an exchange these ETH can then be used to buy US dollar on another exchange in the US dollar network for Alice and Dave this will be all transparent it will be just one atomic ethion transaction and this is is how Alice can do a cross currency payment to Dave so let's now talk about this middle layer I presented before so why do we even need this relay service so as we learned for a payment we need to find a valid path and preferably we want to find the shortest one because that is the one that will save gas because we don't have to update so many trust lines but it's not feasible to do this calculation for the path on the phone because you have limited memory on your phone and it's also not feasible to do it on chain just because the computation is too expensive so relay servers are essentially just helper service to calculate this path and in our current setup will be used as a gateway to the blockchain or this could be could be changed later by using light clients um introducing these relay servers however create a different kind of problem because we no longer can enforce by the smart contracts with path which path will be chosen right so the only thing that the smart contract checks is that the path is valid so that all the balances stay within the credit lines but we cannot enforce which path um this is important because there's for example one property that we want to have in our system we want to balance out and cancel debt um so to incentivize this behavior we uh aim but this is currently this is currently a work in progress we're not really like done with this we aim for like implementing a fee and reward system um to incentivize this balancing out so there will be one fee that we call the the imbalance fee reward um this is uh to be paid by users adding imbalances to the system and it gets rewarded to the one uh decreasing the imbalance there's another fee reward system for capacity that we also want to include that is just to incentivize providing capacity um and this is also this is basically paid by the one using the capacity to root of transfer and gets rewarded to the one um uh providing the capacity yeah there will there are also mandatory fees that we will have um that obviously the gas fees for the ethereum um system uh and there will be probably related uh server fees because um we need to incentivize running dedicated relay service by third parties yeah so how would how does it affect now the path finding algorithm um the path finding will obviously look for subsistence capacity and the shortest paths to save gas but now with the new fees it will also aim for minimizing uh uh the edit imbalance or even cancel out depth so let's look at this following example uh if Dave wants to pay bob and there are two uh say a path with the same length one over earl and one over charlie um we can see here that the um upper path is uh worse because it will add it will increase the already existing imbalances where the lower path will cancel out depth so will actually not increase the overall imbalances within the system so if we add those fees the lower one will be slightly cheaper so Dave will um will hopefully choose this path um so that was it about uh what i wanted to present a little bit about what we're working on um our current project status right now is um we have a working prototype on the on the robson test net it already uh we already have uh implemented the currency network uh with mediated transfers direct transfers and we can give you just our credit lines um we are cool really working on new features we are working on implementing the just the fees i just mentioned um we are working on implementing the decentralized exchanges and other features i didn't talk about yet um we're also working on the mobile app um you can you can watch our progress on our github repository and if you want to know more about the general idea we have a white paper on our website you can also check that out um i want to emphasize that we aim to create an open protocol so we're working on open apis um you can also check that out on our repository um for the relia servers we aim for a restful api and we want to implement we want to develop a javascript library that makes it easy to um to also develop third party mobile apps besides the one we will uh actually um build and we also want to aim that it will be easy to use um our mobile app but also a third party mobile apps together with each other so make payments from one app to the other yeah so uh let me summarize that um we at primer technology work on an open protocol for decentralized i use based currency networks this will enable global payments based on a network of already existing uh individual trust relationships we think it's an old but powerful idea that can increase adoption of cryptocurrencies and made it uh easier to access for everyone uh thanks everybody and if you have questions or if you want to uh want to talk about the idea please feel free to approach us