# Privacy for Everyone by Zooko Wilcox (Devcon4)

- Channel: [Devcon](https://streameth.org/devcon)
- Date: 2019-10-09
- Duration: 41:09
- Topics: blockchain, smart contracts, distributed ledger, Science & Technology
- Watch: https://streameth.org/watch/yt-TFL5LGO3tUE
- YouTube: https://www.youtube.com/watch?v=TFL5LGO3tUE

## Description

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https://archive.devcon.org/archive/watch/4/privacy-for-everyone

Zooko Wilcox speaks about Zcash & recent advances in Privacy.

Speaker(s): Zooko Wilcox
Skill level: Intermediate
Track: Privacy
Keywords: zcash, cryptography, regulations

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Devcon 4 was held in Prague, Czech Republic on Oct 30 - Nov 2, 2018.
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## Transcript

Hello. Thank you. Thank you all for being here. Thank you all for coming. Um I I saw the presentation by Amber Baldet and Patrick Nielsen yesterday and there was a really good joke when they got to the part of their presentation was that was about their own project. Amber was talking and Patrick stopped her and interrupted and said, "Have we reached the shilling point?" Uh so, my talk today is 100% about Zcash. So, it's like all shilling point. Um but not in the sense of asking you to buy more to pump the price, but to share a bunch of stuff that we've learned recently in cryptography and in regulation that everyone else can hopefully reuse and benefit from. Okay. First of all, can we bring up the house lights so I can see you better? I can see these people. All right. Will everyone please put down your phone and stand up for a minute? You in ZZ99 up there, would you please put down your phone and stand up for a minute? Okay, everyone except that guy has stood up. Okay, good. Uh If you have never heard of Zcash, will you please sit down? Okay, great. Wow. Okay, so if you've heard of it, but that's really like you've just heard of it, but you don't know anything about it, would you please sit down? So, that's like 10th. Okay, sweet. So, then I can skip that part, which is good because I was practicing my talk this morning and I found out Oh, like the rest of you can sit down, too. Thanks. But don't get your phones out. Leave the phones out away. Uh yeah, I was practicing my talk and I realized that I put like an hour's worth of content into the slides and that we have 28 more minutes and I want a lot of questions. So, I'm going to talk too fast and skip a lot of the technical content. But, the goal is to say uh what we've just recently accomplished in cryptography, a couple pointers to possible future work that other people might also want, and then talk about the regulatory situation. So, what we've just now accomplished, Zcash, as you all know, except for that guy and like 10% of these guys, is a separate cryptocurrency that uh includes encryption and cryptography to make all the transactions private, and it was launched 2 years and 4 days ago on October 28th. So, Zcash is 2 years old, and that makes it, like Ethereum, a grizzled veteran of the space. Um and uh and 4 days ago on Zcash's second birthday, we introduced the first major upgrade, which is called Sapling or Zcash 2.0. And the improvement, so the first thing we did, which most of you probably kind of know, is we pioneered the use of zero-knowledge proofs. Just real quick, raise your hand. Do you know what a zero-knowledge proof is, or you've heard of it, or whatever? Great. This is great. What a great audience. Um So, I'm really proud that zero-knowledge proofs are so widely appreciated for what they could potentially do today, because uh Zcash was the first application of them to anything in the real world, as far as I know. That was 2 years ago. But, the first version we put out 2 years ago was not efficient enough. It took 37 seconds on a uh supercomputer laptop, and it was not even possible on a mobile phone to generate the zero-knowledge proof necessary to protect a single Zcash transaction. Uh so, what we've just activated on mainnet 4 days ago is Zcash 2.0, and we've reduced the time from 37 seconds in the first version to 2.3 seconds in the new version. Thanks. Yeah, so that's really great because now it's possible for people to generate these on their mobile phone. No, no one's actually implemented it and made available. There's not a a client yet for someone to download and use, but the cryptography has made it possible to implement that client and for every exchange everywhere to support these zero-knowledge proof-based transactions and so forth by Corey. And um Oh, Corey's just getting ready cuz he's next. Um So, real quick, the there are basically three components of the cryptography uh that we have worked on for the last 2 years. We have a really really great team of cryptographers and engineers who've been working on this really hard for 2 years straight to get us this far. So, it's really uh a substantial advance that everyone else can benefit from because it's all open source, all the science results we had to come up with have been published in peer-reviewed science papers. Uh we didn't apply for any patents and there's no barriers to anyone else reusing this for any other purpose. Um Okay, the three major advances we had to do, uh the first one is replacing the hash function inside the so-called circuit that you have to prove when you make a transaction. And um this is potentially useful for a lot of other people because hash functions are used everywhere. Uh a great cryptographer once said that hash functions are like the nails of the internet. They're used to hold everything together. Uh there's nothing you do that doesn't have at least one hash function inside. Um well, uh two of our cryptographers came up with uh a more efficient way to make to implement a certain kind of hash function called a Pedersen hash inside of zero-knowledge proofs, and all by itself this reduced the run time by 75%, which is a really great improvement. Uh you might be able to use this yourself, but you have to be careful because SHA-256 and Pedersen have slightly different properties, so it's not just a simple drop-in replacement for every use. Uh and the result of uh like 9 seconds per like per payment is still not quite good enough. So, we kept looking for a couple of other innovations that would improve the performance uh while being safe enough and practical enough that we would be able to deploy it. The next one, well, this is a complicated slide. I'm going to gloss over this, but this is a bundle of a proving system which is a SNARK. That's BCTV 14 which we upgraded to Groth 16. 14 2014 and 2016 are the years that these science papers were published. Um there's an elliptic curve with a BN128 that we upgraded to BLS12-381. And um by the way, we helped Ethereum add BN128 into Ethereum in the Metropolis upgrade. Uh so, now we have different elliptic curves from each other, but whatever, that's probably fine. Uh and then there's the implementation which is just open source library that anyone can use. The older implementation is called libsnark and the new implementation that we wrote over the last 2 years and we've now deployed is called Bellman. Uh the old one's written in in C and assembly except we never used the assembly cuz assembly is dangerous. Uh and the new one's written in Rust which is even safer than C. And all of this stuff is reusable for any zero knowledge proof system. And all bundled together it gives you twice as fast uh which can be necessary for some uses. And then the last thing is I think called a split circuit design which I probably don't have time to explain, but it gives us another 50% improvement and that's how we get down to 2.3 seconds for a typical transaction. That's where we're at today. Okay. Next, um where would we like to go next? Well, Zcash 2.0, Sapling, um it's really fantastic. Uh it might be good enough for the foreseeable future, but there's at least one thing that bothers me. Uh the SNARKs, which is the proving system that we've started with all along, it has this thing called toxic waste or what I call toxic waste. Uh cryptographers call it a structured reference string, uh but toxic waste is a much better word because it makes it clear to you that this is a thing you should worry about. Um if the toxic waste is a unguessable long random number, it's like a private key, and if you knew it, you could forge Zcash out of thin air. Now, that's terrible. Uh but it but even if you knew the toxic waste, you can't violate anyone else's privacy. You can forge new Zcash for yourself, but you cannot see or manipulate anyone else or anyone else's Zcash. So, there's a limit to how bad it is, but it's still pretty damn bad. If you could forge Zcash, that would ruin the whole point. Um so, we went to this extravagant effort and did, I'm pretty sure, the most secure, sophisticated cryptographic ceremony ever in 2016 to set up the system while preventing the toxic waste from ever coming into existence, while making it making sure that nobody at any moment ever had a chance to generate that number. And then we did a way, way more sophisticated and secure ceremony uh last this recently, this year, uh for the new version. So, I'm really sure that the toxic waste can't possibly exist, and a lot of people in this room actually contributed to that process to make sure that even if I were cheating and trying to steal a copy of the toxic waste, they're they would have prevented me from doing that and vice versa. However, this still bothers me cuz for one thing, I can't convince everyone else in the world of this. They can There can still be a FUD where someone says, "I don't know. I think maybe Zcash is saying that but he and a hundred other random people around the world were actually secretly in cahoots." So, it would be cool for Zcash as well as for other uses of zero knowledge proofs if you could use one of the newer proving systems which have no toxic waste. Um and this slide is all about how we can't yet in Zcash because we need all of the fields to be green for it to be efficient enough to put into the Nakamoto blockchain design where the like the Zcash sapling design where every transaction has to have a zero knowledge proof generated and then the proof has to be transmitted with it and then verified by all the miners. That puts a lot of constraints on the performance and the new things like STARKs which was a hugely popular overflow talk yesterday by Eli Ben-Sasson who's one of the Zcash founders. Uh STARKs uh take 45 kilobytes at least per proof string and that 45 kilobytes is just way too much to put into the blockchain with every single transaction. So, that's a non-starter for now. Um Bottom line is there's only one row so far uh that we can do this with. Um Okay, so but we So, other people could use STARKs for other things that have different performance constraints. Um and uh and we could potentially improve Zcash in like Zcash 3.0 with a few possible techniques that I'll don't really have time to explain. Here are four things that you should take a picture of cuz I don't have time to talk about them, but they might be useful for Zcash or other zero knowledge proof systems for like the next generation. And we have some very rough estimates of how much savings we could get. So, it's like it's close. It's interesting. All right, I'm just going to scoot along. Um Here's something else I totally don't have time to talk about which is uh What if we change the architecture? Okay, I have time to talk about it. What if we change the architecture so it's not a simple Bitcoin inspired Nakamoto consensus where you have to generate a zero knowledge proof with every transaction and then carry it along as and so what's good about it is that we separated privacy from mining. You know, the the all the privacy happens on the end user computer who generates an encrypted and zero knowledge proven transaction. And then all the rest of the consensus algorithm just deals with these encrypted blobs. But what if we changed it to new consensus algorithm, sharding maybe you can use zero knowledge proofs to solve some of the problems in the some of the currently unsolved problems in consensus algorithms and sharding. Anything like that would open up the constraints back here so we could if we had a much much more high bandwidth consensus algorithm then we could use STARKs even though they have like uh two orders of magnitude uh bandwidth requirements and stuff like that. Okay. Um Possible changes uh not coming anytime soon to Zcash because we're conservative and it took us two years to upgrade the cryptography. It'll probably take another two years to make the next upgrade. All right, now I mentioned back here one of the three improvements that we've already uh, vetted and gotten security audits and deployed and tested and then activated on mainnet and now people are using it today. The third one is split circuit design. And it's specific to a payment system like Zcash. It's not Well, I don't know if you could if you could apply the same kind of principle to other zero-knowledge proof systems, but I'll describe it real quick. This is the old Zcash 1.0 core. This is um, all the bits of data coming in and out that need to be proven by the zero-knowledge proof. You don't have to understand any of it except for what these big old things on the left Z UTXO, that's two coins that are being consumed and two new coins that are coming out. So, if you are paying someone, you're probably going to consume a coin that's worth 10 Zcash and you're going to give them five and then you're going to give yourself change for five. This is the so-called UTXO data model from Bitcoin, which is different than the balance data model from Ethereum. So, the zero-knowledge proof in the original Zcash 1.0 has to prove the correctness of all of these pieces uh, even if you were only spending one coin. You have to prove the correctness of that coin and a dummy, which takes twice as long. So, the split circuit design is we'll have two proofs. One proof that you're consuming a coin and a different proof that you're producing a new coin. And that way, if you're consuming only one coin, you only you don't have to prove that you're consuming two coins. And that all by itself is a 50% savings. But the and it's useful for all UTXO style uh, systems. Um, earlier I said it's for transaction systems, but the UTXO style might also be useful for um, Ethereum style smart contracts. There's a new paper by some scientists that include some of the Zcash scientists called Zexe, z e x e, uh which describes how to extend the Zcash style data model and zero-knowledge proving system to um prove the validity of arbitrary smart contracts without uh without having the miners run all the smart contracts. So, instead of the execu- instead of someone submitting a smart contract or executing a smart contract and all the miners run it and then they consensus on the resulting output, instead the first person runs it and generates a zero-knowledge proof that this is the correct output. And then all the miners just verify the validity of the zero-knowledge proof. That's uh that's a new paper. Um Okay. Oh, good. I'm going to have lots of time for questions. I hope you have questions. Cuz I totally glossed over all the complicated stuff in the last two slides. You can ask me about those if you want. All right. Finally, about the regulatory situation. So, um you have probably heard that law enforcement and regulators and governments uh fear privacy or that uh privacy technology like Zcash is incompatible with regulation. And I'm here to say that's totally wrong. It's not incompatible with regulation and the actual regulators are not afraid of it and are not trying to prevent it. So, there's this widespread misse- like a common myth that is uh that is the actual problem. It's not the regulators that are the actual problem. Um here's the current very simplified state of the important things in the world, which is that almost everywhere the legal status of cryptocurrencies in general and Zcash in specific is ambiguous. In China and in India, it is all cryptocurrencies, Zcash, Bitcoin, Ethereum, etc. are all effectively banned. Um and here's the really interesting little appreciated fact that I want to tell you. In the United States, there's a regulator called the New York Department of Financial Services, which is the most important regulator of cryptocurrencies because even though technically they're only supposed to be regulating the state of New York, but almost every company who wants to serve Americans does not want to exclude New York. Um and this this regulator, the New York Department of Financial Services, set themselves up as the uh the gatekeepers and the arbiters of all cryptocurrencies years ago when they made this thing called the BitLicense, which says uh if you want to if you're a company, you want to sell cryptocurrencies like you're an exchange or whatever, you want to allow people to trade in cryptocurrencies, and you're serving citizens of New York regardless of where you're located, if citizens of New York are among your customers, then you require our prior permission to do anything. That's That's how the BitLicense works. And um so therefore, all the cryptocurrency companies have been queuing up to ask this regulator for permission to do all the things ever since. And here's the little understood fact. That uh that regulator has approved like about seven different coins as being legal for people to serve to the citizens of New York, and Zcash is the seventh one, the most recent one. Yeah. Thanks. That's really important. And um and they explicitly went so far as to put out a press release under their like official logo and the name of their official leader and superintendent and all that. Which expressly mentions the encrypted feature of Zcash. Um and when I tell people about this, they sometimes ask me what you know why did they do that? What are they thinking? Um and I don't know for sure cuz they didn't make a they didn't give a justification or an explanation of their decision in their public press release. And I met with them in private to explain uh cryptography to them many times um and they didn't tell me anything in private either cuz like they're the government and they're the ones who ask the questions. Um but one thing I do know is that I've become very familiar with all the rules and regulations in the United States and in Europe and so on. Um and one thing I do know is that Zcash and cryptography mixed with blockchains in general is absolutely compatible with the rules and regulations as an exchange or any business that's dealing like the regulations the way that's currently done they apply to businesses like exchanges or financial institutions. They don't apply to program software developers or individual users. But um as an exchange you can comply with all of the requirements while supplying encrypted Zcash to your customers. That's that's a fact. So that's something that the NYDFS the New York Department of Financial Services and my team discussed. And then this really interesting thing happened where they called my team back to New York for another meeting. I've never talked about this publicly before. And I thought to myself I think we covered everything in all the previous meetings. So, it's not clear what why they need another meet. Maybe it's to tell us something. And we all like filed into the official building in New York City and we all lined up on the opposite sides of the official table and they opened the meeting by saying the leader of the NYDFS who was present in the room gestured to their colleagues and said we all agree that we don't want the pocketbooks of our families and the citizens of our communities to be exposed to everyone on the internet. Yeah. So, that's all they ever said. That was it. I think that was why we had that meeting. But I think it really shows that regulators and the rest of us in this community share a lot of values. We want a safe and prosperous society and we all want a society in which the citizens have meaningful political participation. And we want people to be protected from crime and fraud. Um and encryption technology is compatible with all of that. I'm reminded of 25 years ago now when I was playing a tiny niche role in an earlier round of this drama when SSL was being invented, SSL/TLS. And at that time the United one small faction within the United States government headed by the FBI and Al Gore and the NSA opposed the invention of SSL cuz it might like allow criminals to use the internet or something. And that's funny now because 25 years later the US government requires you to use SSL, right? There's a ton of laws which say if you do not use SSL to protect your customers, then you are in violation in a lot of specific cases. And I kind of think that's the same thing that's going to play out with encryption on blockchains. Eventually, and hopefully a lot less than 20 years, all of the good regulators in all of the good countries will require this kind of encryption to protect the people. And lastly, I want to say that I myself and everyone involved in the Zcash project is doing this just because we care about what kind of world we're building for our children and grandchildren to grow up in. Because privacy is a human right and it's necessary for political participation, for morality, and for intimacy and human relationships. And it is not okay for our societies to continue careening into a world where there's pervasive and intimate violation of everyone's privacy by one or three centralized actors. That's never been tried before. It's wrong and it's dangerous. Thanks. And and all of us are part of our opportunity to change that and to make a world that's safe and healthy for our children to grow up in. That's it. Ready for questions. You got to come down to the or you got to acquire a mic so that the people on the live stream can hear the question. Thank you. Um thanks for your thoughts and I really like how you actually twisted that whole thing that whole thing that people often say about like think of the children, right? Yeah. But but in the right way, right? That's really good. Um, so I wanted to ask you what your thoughts are on similar privacy projects like Monero and I also wanted to ask you about uh, smart contracts and other features that you seem to have uh, not focused on yet and if you have any intention to look at those. Well, those are two big questions. Okay, so first of all, there was a really great talk by Zcash founding scientist Ian Myers yesterday in which he laid into Monero um, and all all systems that use what he calls decoy-based privacy. Um, so you should go watch the live stream if you haven't or the recording if you haven't seen it. Um, now the zero-knowledge-based privacy that we have has different problems, but um, privacy is really, really hard and uh, I wouldn't want it to look like we've solved it, but we've made a substantial improvement that everyone needs to learn from. Um, and I I like to work with the Monero people on that and we both benefit from each other. Um, and the other question was about smart contracts. Yeah, so it's something that we I we've deliberately kept out of Zcash and kept out of the public like discussion of the future of Zcash in order to keep things simple. Like in theory, we could extend Zcash to execute arbitrary smart contracts. And as of about 3 weeks ago, maybe, a few scientists that include some of our scientists published a paper describing in a lot more detail how that would work and what the efficiency would be and what the security properties would be and so forth. Uh, but so far I kind of want smart contracts to keep working on Ethereum and just pure private payments to be the focus of Zcash. Um but that could change. Hey, um so besides just winning the um or educating users about shielded transactions, could you talk a little bit about the rest of the stars that need to align across governance, business, and technology to make that become a default? Well, um Amber, the questioner, is a member of the board of the Zcash Foundation, which is a a separate thing from my company. I'm the CEO of the company, and the Zcash Foundation that Amber's a director of is a completely separate independent thing. Uh and it sounds like a question that Amber should answer. What was that? Aside from it's it's aside from educating users, governance, and business, um Oh, can I have my slides back? I have a slide about this. Anyway, uh a major the major touch point between Oh, yeah, thanks. Perfect. Uh the the premier touch point between regulators in the technology and between users in the technology right now is exchanges. Right? This is a map of all of the exchanges that already um provide Zcash to their users. And so they are actually the most effective both at educating the users and at educating the regulators. Um note that there are none in India or China. Uh there are lots in US, and there are lots in Singapore, Hong Kong, Korea, etc. Um Um one more thing that is really necessary is better UX. As everyone, I think, has figured out, we've all done this backwards by building the technology first and then trying to figure out how to put a user experience on top of it. So now we have to fix that and make a really good user experience and then figure out how to fit it to the technology. That's my answer. Any other questions? Yeah. Do you think a connection between Zcash and Ethereum is possible? Oh, a connection between Zcash and Ethereum? Oh, that's a great question. Hey, listen. There's this EIP for Blake2, a secure hash function. Uh please please contact your friendly neighborhood Ethereum developer and tell them that you support the Blake EIP because that would be one way to reduce the gas costs of um of Ethereum smart contracts evaluating the Zcash proof of work, which might allow certain kinds of connection. Um there's this whole crazy idea that is not is purely hypothetical, but Vitalik brought it up first, so I can say it, which is uh Zcash and Ethereum could just merge. Uh So, like I don't know how this would work. Yeah, thanks. I appreciate the support, but in the meantime, I think uh people using multiple different networks and technologies for different purposes is the the practical the pragmatic thing to do. Um but there there are a few technical technical ideas for how we can have decentralized trustless cross-chain interop. Um and one of the details that would help is the EIP about Blake2. Thanks. Question over there. Hi. Um I heard you say a couple of months ago on a podcast interview that at some approximately 7% of all the transactions on Zcash are shielded. Um what's the state of the shielded transactions today, and what needs to happen that technically we will see more of them? Right. So, um very So, Zcash, I didn't get into this. Zcash supported backwards compatible um text mode. It's like HTTP and HTTPS. For for a long long time, everyone still supported HTTP, but then more and more people started supporting or even requiring HTTPS. Similarly, Zcash allows the old Bitcoin style non-private mode. And the questioner was pointing out that most transactions use the only the old unencrypted mode. And what needs to change? So, the first There's two things. First of all, well, three things. Sorry, it's a lot, but first of all, the cryptography, which is the whole first part of my talk, is that we needed to reduce the computation cost from 37 seconds on a laptop down to like a couple of seconds, so that that reduces the barrier. By the way, this also reminds me when SSL was new, it was expensive. And you know, computers were a lot weaker back then, and that was one of the reasons why it took so many years for SSL to become ubiquitous. But the other one is all these exchanges need to start supporting These exchanges need to start supporting the encrypted mode in order to protect their users. And they need to understand, which they mostly don't because of this FUD, they don't realize that the regulators are almost certainly okay with that. They just need to tell the regulators, "This is user protection. It's compatible with all of the regulations, and we need to do it to protect users." So, after you contact your friendly neighborhood Ethereum developer, contact your friendly neighborhood cryptocurrency exchange and say you want encrypted shielded transactions like SSL instead of HTTP in order to protect you. The last thing is UX. Like we're making a new wallet and stuff that I didn't have time to get into. Any more questions? Hi, thanks for moving this project forward. So, I have a question about So, say you are doing a service for the business, where the business resolve their transactions payments. And of course, yeah, there is this notion of privacy that, you know, counterparties they different parties they don't know they don't want to know about like with who the business is done. So, perfect use case. Do you think that up to your knowledge if on the top for the tax reasons some regulatory or tax authority could come and ask to the service provider so, let's say in this case which is built on top of the Zcash to reveal all the details about like a certain entity? Okay, I think I understand the question. If you have encrypted transactions on a public blockchain like Zcash can some party in your case it's a tax authority come ask some other party to reveal some of the transactions? Yes, this is a really ill-appreciated fact about encryption. Encryption doesn't give you all dark all the time where no one can see anything. What encryption gives is selective disclosure of data. So Zcash is the first ever thing that it combines the blockchain properties of canonical append-only data with the encryption properties, which is that if you have the decryption key that lets you see some of the data in the blockchain, you can give that decryption key to a third party and then they can see that data in the blockchain. See what I mean? That's really interesting. Yeah, so it's subtle, but the bottom line is it's possible to reveal data to some parties without revealing it to unauthorized parties in the blockchain, which is good. Yeah, but that would require to share the private key? No, not the not the key that allows you to spend money, a different key that allows you to see the transactions, um but not to spend the money. Make sense? Hey Zuko, you talked a little about the regulatory landscape and the ban in India. Do you have any like more insights to share or anecdotes from what's going on out there? Uh From a regulatory It's not too much my place to say. I mean, the the the government of India banned um banks from serving Bitcoin companies in India several weeks ago, and then just a few days ago the most terrible thing happened. Uh one of those Indian Bitcoin exchanges, which is one of the longest serving Bitcoin exchanges in the world, um they set up since they were since the banks had been required to cut them off, they set up ATMs that would take rupees in paper and give you Bitcoins. Okay? Uh because that was like the only remaining legal thing for them to do. And then the most horrible thing happened about 2 weeks ago is that they were arrested. Which doesn't make any sense under the law any law that I've heard. I don't know what's going on. Welcome to government. So, that's uh that's the last thing I heard about India. Thank you. Uh Zuko, as somebody who thinks about privacy all the time, um and can you paint a picture for us? Um let's say, you know, projecting from today to n years into the future, how would decentralized applications actually provide privacy for people not just on the transaction level, but on many different levels? Yeah. Um that's that technology it it's possible technologically, and there's this thing called Zcash, Z E X E, which is a science uh paper that describes a technology that could accomplish something along those lines. Um, it's possible, cryptographically speaking, to, um, have shared, you know, distributed apps which you get the um, the property you want. I don't know the right word for it, but the property that you know the app is going to do the right thing and it can't be like subverted by the owner of the server since there's no server. Uh, you can have a distributed app which when you use it, you don't have to link what you're doing to anything else about you. You don't even have to necessarily reveal the moves you're making within the app. So, it's a lot of work. No one's actually implemented it yet, but scientifically it's possible. Why do you think the, uh, adoption of Zcash on darknet markets has been almost zero? And is that something that bothers you or do you not really care? Why do I think the adoption of Zcash on darknet markets is almost zero and is that something that bothers me? I think, you know, my best guess is, so, I mean, part of it is I've made some, uh, tweets saying, uh, "Screw you, criminals. Go away. This isn't for you." And, um, and that doesn't really change the scientific or the open-source code, but I honestly think, cuz I I heard this from someone who studies like the criminal underground, that criminals don't trust Zcash cuz they don't trust me. And that doesn't bother me. I think that's that's good. It's like the darknet markets are a a shitty, uh, a shitty early adopter market because they're they're small. You you wouldn't make They wouldn't be very active users. It's a tiny little minority. And then it would turn off the rest of mainstream society who would associate you with crime and drugs and whatever. So it doesn't bother me. Uh so how how Zcash is expanding in Japan? There are some outlets which can legally accept currencies put on balance sheets. Are are there any obstacles for wider adoption into fiat world because of this privacy? understand the beginning of the question. How how is Zcash what? Yeah, so are there any obstacles from regulators and other authorities to use Zcash in Japan? In Japan? Yes, in Japan. Uh where the cryptocurrencies are allowed to be used for buy and sell local goods. There there is an obstacle which is the There's a a Japanese self-regulatory organization which is the Japanese exchanges. Um that have published a draft proposal for how they think the government ought to regulate them which says that the government should require them not to supply Zcash. And I think it's a mistake on their part is that they like a lot of people incorrectly think that encryption is incompatible with consumer protection and email KYC processes and computer security and all that. Uh so I'm hoping that they will notice the example of NYDFS doing the opposite. Maybe they'll even learn from the example of HTTPS 25 years ago, but that's currently in play. So so Japan is gray on the map because it's not it's an ongoing conversation right now. It's not settled. Okay, no more questions. Thank you very much for being here.