Lightning + Ecash An Atomic Match Made in Heaven | Bitcoin 2026

Well, hello everybody. Uh, go ahead and get the laughs out of your system. Yes, I limped up here. Uh, I'm Shinobi from Bitcoin Magazine. Uh, dealing with a world of memes. This is assault. Help me. Somebody call security. So, uh, I I am joined today. >> Said we had to get We said we had to get the fighting out right away. We had to start with the silliness. And uh honestly, let's be real, guys. A lot of people have wanted to shoot Shinobi and I finally had the opportunity and I took it. >> All right. All right. All right. So, I'm joined here today by Alex Leuen of Fetty, Evan Kudis, uh founder of Zeus, and Eric Kativo from Cashew. And we are here to talk about the latest and greatest Bitcoin fork that's coming at the end of the year. Have you guys heard of Ecash yet? e-cash.com. Yeah. >> God. All right. But, uh, in all seriousness, uh, >> your airdrop, >> uh, we are here to talk about the synergy between ecash and lightning. uh you know, Lightning up until the last few years had kind of held a monopoly on the mind space of Bitcoin layer twos and how are we going to solve payments at scale for people and over the years since it's been created we've found more and more cracks and shortcomings and limitations and along came eCash in addition with some other solutions and they've uh been playing very well together. So, I guess do we want to kind of just go down the line here and get some short thoughts on why these two protocols projects have kind of meshed so tightly together in the last few years? I guess start with you, Alex. >> Yeah, sure. Um, so Lightning's amazing. Everybody loves Lightning. Uh, Lightning is the best thing since dice bread. Um, but when you first receive a payment on Lightning in a non-custodial manner, it's a pretty terrible user experience. You have to wait for the the channel to open. Uh if it's a zero comp channel, there's more trust assumptions. Um and you have to pay a pretty hefty fee out of the first payment that you receive. Um and also if we get the whole world on lightning, then it would not scale uh because you just could not open channels fast enough. So uh ecash comes along and it fixes this last mile problem. We can still use lightning to settle payments between users across uh the network and across the world, but uh as the last hop to get to different pools of users, we can use ecash to get there. and you can have virtually a perfect user experience for um for using lightning. >> All right, Evan, do you have an interesting way to say the same thing? >> Yeah, absolutely. Hey guys, my name's Evan Kudis. I'm the founder of Zeus. We're free and open source lightning wallet. We started as a remote controller only. Then we built a node in the phone. One click to get started on Lightning and we added an LSP. And then recently we just launched our graduated wallet. You can start with Cashew optionally. It's Zcash. It's custodial, but the wallet uh sort of guides you to self-custody. As your balance grows, it says, "Hey, you got a lot of money in Cashew. It's custodial." Sort of like a bank, albeit, you know, with much much better privacy. And uh, you know, within the UI, you can learn about self-custody with one button press. You can upgrade this health custodial lightning which is now powered by LDK in the new Zeus or you can do a swap onchain and send it to a hardware wallet or any onchain address you own. And um yeah, Alex's points are all true about the pains of onboarding with lightning. Um you know, you got to get these channels set up. There's these new concepts of inbound outbound liquidity that a user has to learn about. Um, and there's a real cost to getting those channels set up. Like we're pretty proud about the cost that we've got it down to for Zeus users. It could be like five, six, 7,000 SAS to get a channel, but let's be honest, like no one really wants to pay that just to test out a wallet. So, what we've done is uh we printed out 6,000 of these notes here uh with seven different designs that we were handing out across the length of the conference. And uh yeah, it's just such a great onboarding. You can scan it with your uh we got a couple blanks. We uh you can scan it with your phone's camera. It takes you to a onboarding portal uh guides you to download Zeus and then you can import the token either into Zeus uh or any other cashew compatible wallet. And uh we've already had a lot of awesome experiences just giving newcomers their first SATs, having them install the wallet, receive it with one press of a button, and really just see their eyes light up. It's it's magical. >> I guess Eric, you specifically work on user experience for different things. So what's what's your kind of thought on what they just said phrased differently? >> Yeah, well basically Alex I work as a product designer. So Alex pretty much covered all of like the UX aspect. So I'm not going to repeat that. Instead, what I'll say is like there's this kind of social uh this social idea that I've noticed among Bitcoiners. We're all at a Bitcoin conference. So, that means that you are inherently an enthusiast. You are an outlier. And we believe certain things. We believe that self-custody and sovereignty of your money is a virtue. That is a good thing that you should be doing and we think that that is good. However, there are other people who don't think like us and they just don't see that as a virtue. They see that as a liability. You explain to them the responsibility of having your own keys and what that entails and they're turned off by that. We're turned on by that, right? They're like, I don't want that responsibility. I want an experience that is like, forgot my password, send it to me so I can log in again. And we I think we as Bitcoiners sometimes have this idea that because we think self-custody and self- sovereignty is virtuous, we want to present that as the default to someone that is not at a Bitcoin conference or is not at at a Bitcoiner. And that can be very dangerous. This could be like giving putting someone who has never driven in their life in a 1976 uh Volkswagen GTI on the German Autobon. They're going to get hurt. They're going to get wrecked and it's a stick shift and they don't know how to drive stick. You're setting someone up who is going to get hurt because they are not a car enthusiast. So, I think the the UX experiences and the UX trade-offs that Alex mentioned, there is a role for that. And what I also want to emphasize is that Cashew right now and ecash, not just cashew, but e-cash in general has some of the best privacy properties on Bitcoin. And a huge impact that we can have is make custodial services a lot more private uh than what exists now. That is a massive win for Bitcoin if we can make custodial services more private. And that's something that I'm very excited about because I want people to be able to transact with Bitcoin easily privately and very importantly always have the option to go to self-custodial self- sovereignty with lightning and then onchain. You always need to have that option. >> All right. And something I wanted to touch on. Um I like starting fights. Alex, you you work for Fetti and you know Evan and Eric, you guys both work with Cashew. Like these two different eCash systems have taken like very different tradeoffs in terms of user security or trust model. You know, Fetty has the guardian system where you have multiple signers or operators actually operating the mint, whereas Cashew is just a single key, a single operator and kind of to try and have some of the risk mitigation um that Fed does with their structure. Cashew has been doing a lot of research and development in spreading your ecash balance across multiple mints rather than having it all in one and kind of sourcing um that liquidity when necessary to make payments over lightning. Um I guess to invert things, toss it back to you, Eric first. Do do you want to talk a little bit about like the trade-off Cashew has decided to take there and kind of the the thinking and the the progress towards that? Yeah. So there's there there's two things like I I don't want to speak too much about about Fediment because it's not a project that I'm like as intimately familiar as I am with Cashew, but I will say every single developer that I've talked to um that has looked at Fediment has said it is an absolutely like marvel. It is like an incredibly well-gineered a very like serious piece of engineering software and it is um the team there is crack. They know what they're doing. >> Tell me what you really feel. Cashew has taken a different approach. And that's not to say that Cashew isn't like uh software engineer to that caliber, but there's an ease uh of of launching a Cashew Mint that is a lot easier than than launching a federation, right? It's a couple lines of code. It's very easy to deploy these mints very very quickly. And when we think about decentralization and risk mitigation, at least I come from the world of private trackers and torrent. And one thing that I was always inspired was this idea that trackers and torrent it's very easy to spin up, right? And even though there is that risk where your torrent tracker might go down, there's going to be another one that spins up right away. And that's kind of the the resiliency is that these mints can just spin up and operate right away. Another thing that we touched on um that you kind of alluded to was multi-nut payments. So instead of having your uh your cashew ecash on one mint, you can spread it across multiple mints. And usually that would be kind of a UX nightmare because now you have $20 here, $20 here, $10 here, and you want to make a $40 payment. This is going to be very annoying. But with multi-nut payments, uh what that'll do is automatically on the back end totally abstract it from the user. You'll just scan an invoice or you'll want to send a payment and it will automatically pull the balances that it needs from the necessary mints where you've already like spread across your risk and then perform the payment. So that is kind of a way to build a little bit more resiliency that doesn't rely on kind of the the security model that I just mentioned earlier of like relying on uh these mints just kind of spinning up and then going in and out of out of existence rapidly. And I think the uh the fetty mint and the guardian approach is is great. I think that's you know an incredible way to go about it. And I think it it could make sense in uh when you have like a larger group of uh uh if you have a community with guardians where people know each other and they want something that is um maybe a little bit more robust and resilient. >> Alex, you kind of want to jump in and talk a little bit about Fedman's trade-off decisions there. >> Yeah. So, um Cashew is a super cool project. Uh Cashew and Fedmans are uh are very close friends. >> Um yeah, >> I you guys come on fight. I was I was trying to start a fight. um you want that. >> So Cashew strengths is that it's uh it's agile. They build features super fast because the protocol is relatively simple. Um you can do a lot of cool things and push the boundaries of what's possible with ecash. Uh fedment has a bit of a different set of priorities. Um like you mentioned um fetamament is really two things stapled together. First and foremost it's a custody solution. So it's a federated custody solution uh where you can have like a three or four set of guardians and uh any single server can go down but the mint has uh zero downtime. Um and so yeah so it's first a custody solution and it's seconds in e-cash mints. So um yeah it's fed's opinion that like in order to really use ecash at scale and kind of trust it without losing money like um without like people losing their money in order for to trust it needs to be fault tolerant. So um yeah, Fed does the hard work of uh finding a way to do the custody solution plus the e-cashman so we can actually do uh uh something at scale um that we can uh trust and believe in. Um yeah >> and I guess uh do you have anything you want to add here Evan given you've made a choice? So yeah, there's a real coordination cost to setting up a federation and I think as a result we've seen a little bit of a richer ecosystem of mints and mints to pick from. I think fetty mint probably thrives a little bit more in like a local setting. I would argue at least at the current moment and uh I I just think a lot of it is also contingent on the legal gray area of spinning up these uh mints. you know, uh how great would it be if we could have a fed mint uh that was uh I don't know, hosted by Zeus, uh and two other lightning wallets and we could spread up the risk there. But no, if I did that, I'd probably get hauled to jail. Uh here in the United States, despite, you know, all the claims that we've made all this great progress, it's like, no, it's still very much this cipher punk thing to to set up um to set up a mint. So, I mean, if that changes, then I think Fetty Mint clearly leapfrogs uh Cashew, but that's not the environment that we're living in today. So, um because of those reasons, we went with Cashew, at least for now. I hope Fetty Mint can continue to be used and uh it becomes easier to coordinate um both from a technical and and legal perspective. Uh but right now, yeah, we're just spreading out the risk amongst different mints. When you get set up with the new onboarding process in Zeus, uh you're recommended uh with our algorithm that uses Nosters as a web of trust to figure out which mints to connect to. Uh we pick five mints for you to have. Uh you have the ability to rotate between those mints when you're receiving. Ki wanted to figure this out at the protocol level, which is not possible. So we figured the application level would be great for that. And then in our following minor release 13.1, we're going to have multimint sending too. uh still a little rough around the edges. It's still a very much experimental feature. Not all mints support it, but uh when it works, it's amazing. >> And I guess in the last 10 minutes kind of want to throw an open uh question or something to ponder on to all of you. So the the core idea here for eCash when like Cashew and began is while lightning is great like it has these last mile problems. there's these costs or just frictions in UX or technical complexity to initially onboard a user or try to use the system for lower value payments. And the entire idea of ecash is to just kind of deal with that last mile problem in the environment of the current day. Like over the last year or so, we've seen Spark like a state chain implementation. We've seen Arc Labs drop arcade. Um I believe uh second's implementation is coming shortly. Like what are you guys thoughts on where eCash fits into this ecosystem given that we have these newer last mile solutions that do have more of a self-custodial tradeoff can come down and handle some low. >> Do they really though? >> Yeah. Like >> yes. >> Uh I don't think so. >> Is trust show. Okay, we'll we'll we'll use we'll use the madeup word trustoio, but in in in that environment of Spark and ARC, where do you see ECH fitting in when you have that competition and that pressure now for these last mile roles? >> Yeah. So, so to start like ecash immediately makes the concession that it's a custodial system and given the one trust assumption that you trust the custodian. Um, you can have a phenomenal UX, phenomenal privacy properties, um, and it's the ideal payment UX period. Um, it doesn't get any better, but there's the one trade-off that it's custodial. So, uh, there there's trust. Um, these other systems are attempting to innovate on that trust assumption. Um but each and every one of these side systems is running into a brick wall with the UX and most of them are making modifications to their protocol that kind of tiptoe around the idea of becoming a multisig again introducing trust. Um so they're coming around to the best you can do in the current Bitcoin without covenants is effectively uh multisig with ecash. it doesn't you can't do anything else um with the the trust assumptions and I think that the community is slowly learning this and waking up to this fact. >> You're lucky I'm a moderator. Evan, uh Eric, >> it's it's all a game of trade-offs. I mean every I've every single person that I've talked to that has looked at these and by person I mean like you know developers who are sophisticated can read code bases um just find different things and it it seems like when I talk to different people I get different kind of assessments. Um I've talked to a lot of people who have looked at Spark and they tell me blatantly this is a privacy nightmare. Uh and that is a massive trade-off. Uh and then Spark will you know say oh well we have this option to make it more private. Then I see other developers like no I just pulled up your Spark address and I see everything. So that's you know that's the reality. Um with ARC I work with other designers who who build on Arc. is specifically like a second tech uh implementation of it that's currently on Signet and this entire kind of VTXO refresh balance kind of UX is is very challenging. It's a very complex thing to explain. It's not simple. Um when I talk to my my design friends, they tell me right now it can't be automated. So the user has to at least right now go in and manually trigger a VTXO refresh. That's a lot to explain to someone. Um why? What does this mean? my balance changes. So that's a that's a kind of a design issue that needs to be solved. And I think this goes to Alex's points that these systems kind of introduce kind of new things uh at the kind of just receiving UX. >> Yeah. I mean both ARC protocols or both ARC implementations have uh made the decision to modify their protocols to introduce some trust because the refresh UX doesn't work. >> Yeah. >> Yeah. >> They need covenants. That's it. And until we have that, then why do all this hand rubbing like shrugging things aside? They all have these in different trust assumptions. Why not use the thing that provides really good UX and really good privacy? >> Mogs everything else right now. But are are you sure it's so black and white given that yes, there are big privacy trade-offs involved, but the trust model of things like ARC or Spark is a little more nuanced than that. Like ARC can be temporarily um kind of trusting the coordinator not to double spend something, but the user can roll something over into ironclad self-custody. Now, Spark is a little trickier. You do just have to trust that the operator is properly deleting keys and there's no way you can ever verify that. But there is a massive legal pressure for them to do that properly because that is why they can say they're operating a non-custodial service and not be subject to those regulations. >> Yeah. It's legal gymnast gymnastics. >> Yeah. >> Yeah. Like I I think Spark is interesting for that reason that like it's this legal innovation that aligns incentives like in order for the operator to um to to be compliant. They actually must delete the keys. So either they're non-compliant and stealing from you or they are compliant and doing what they say they're going to do. But then again, it's like do we care about privacy as far as like a liberty aspect of of money? It's like I I think privacy is pretty important and you get none of that with with Spark. You get none of that with ARC. Um and then also yeah, ARC is becoming more trusted. So, so it's like is it really worth having uh incremental more um call it uh uh trust assumptions incremental better incrementally better trust assumptions in order to compromise privacy completely. Um yeah, in my opinion now >> yeah just it's just marginal. It's just the time window at which the rugging can happen basically at this point and you know quite frankly these legal gymnastics saying oh I have this legal opinion blah blah blah whatever I don't care the state if they want to deem it to be custodial tomorrow they could change their opinion on the drop of a hat what provides the best user experience for users today that's what I care about >> all right so I think the consensus up here is the lack of privacy is pretty much the the big dealer here for you guys. >> Yeah. Also, I mean, privacy has this practical benefit that like improves uh the the call it um like trust assumptions of the user. Um with if you don't have a private system, one of the things you're really worried about as a user is being selectively censored or like being selectively like as you as an individual because the the payment provider can see all of your payments and they they can censor just you. Um and uh this is super annoying because you can get individually get locked out of your bank. But uh if you have a private payment system, then that becomes impossible. You're now sharing in the anonymity set of all of the users of the system. So it becomes all or nothing. So if you want uptime in your system for anybody, you have to allow it for everybody. Um so it has these like practical benefits. Even though it's still a trusted system, it's it's practically um yeah, much better. All right, I guess in the last couple minutes, uh, we want to kind of go down the line from Alex Evan to Eric and give your short spiel what fun stuff people can go do with eCash, what they can spend it on right now. >> Uh, yeah. So, uh, with in the Fed world, um, you can download Fetty today. We also have our own quirky e-cash bucks, and we're actually much more generous than Zeus, so uh, our bucks are worth quite a bit more. Um, >> right, hold up. I have the bribe pile somewhere. >> Yeah, >> hold up. Those are bigger denominations. Yeah, we don't make them rain, but uh they are valuable. Um yeah, if you want to build on Fediments, uh you can check out our docs at fedment.org. If you want to build a wallet, check out the Fed SDK, sdk.fed.org. Um and yeah, uh come talk to us, >> guys. Remember, it's lightning and e-cash, match made in heaven. Anywhere you can make payments with lightning, you can use eCash, melt it down, make those lightning payments. Um so yeah, come check us out isn.com. We got a brand new wallet, version 13, graduated wallet. You can start with Cashew. Hell, we'll give you your first few sets to get started with the wallet. Just come see us. We've got a ton of these bills. And uh yeah, just want to thank you guys all for the support. >> Yeah, the just um I'll close it out. The the most exciting thing you can do is is transact privately and exercise your your human freedom. Um, and I just want to say I think it's a joke that the FBI director Cash Patel and acting AG were invited to speak at this conference yesterday on the subject of code as free speech while Kone and Bill are sitting in jail right now. Pardon and release them and stop the prosecution of open source privacy developers. >> We're here. All right, I'm going to take the extra time because uh it's going to be a minute for me to get off stage. Thank you everybody for coming. Thank you everybody for listening. No, can you clean all this? >> Every year, this community comes together to celebrate, to debate, to build what comes next. And every year, the stage gets bigger. Sound money, center stage. So, where do you go to celebrate the next chapter in Bitcoin history? You come home. Nashville, July 2027.