The next speaker speakers are from Gru Taylor, an online payment system. Our guests and speakers are Christian Grothoff, Jeff Burgess and Serenity. So enjoy this talk. Thank you very much. Thank you. And thanks to the organizers for inviting us to present. Let's start with a bit of a motivation. So in 1971, the American think tank, the Rand Institute, was asked, suppose you were an advisor to the head of the KGB, the Soviet secret police. Suppose you are given the assignment of designing a surveillance system for the surveillance of all citizens and visitors within the boundaries of the USSR. The system is not to be too obstructive or obvious. What would be your decision? Anybody know what the design is they came up with? It's not the internet hint. Yes, they pretty much proposed a design that is remarkably similar to modern credit card systems. So welcome to the USSR. Or some of our friends put it. So to quote Snowden, I think one of the big things that we need to do is we need to move away from true name payments on the internet. The credit card payment system is one of the worst things that happened for the user in terms of being able to divorce their access from their identity. So it's not just that the credit cards have numbers. It's the idea that you need to prove who you are in order to pay. That's the problem. That's a social problem. But it turns out also our friends in the banking industry, they also have a problem called 3D secure or verified by Visa. So it's a very complicated process. You've all probably suffered through it by now. The main feature that it had when it was introduced, I was saying, okay, with the old credit card payments system, we just have to type in the numbers. You as the merchant are liable. If we do this new thing, you have to enter your SMS receive pin or some other things. Then we can shift the liability to the customer. So that's the main new feature that they introduced. Introduce a significant latency. So if you want to do a credit card payment process, if you can do this under 30 seconds, you are really, really good. It can refuse valid payments. At least me, who I'm traveling a lot, I frequently get, well, payment refused. You're in the wrong country. What on earth are you doing in the Netherlands? Legal vendors can be excluded. So various legal shops have been told, well, we're not going to process your credit card payments anymore.  And of course, as a buyer, you have no privacy. So this will be replaced simply because the technology is so awful. The big question is with what? So there's one proposal, a family of proposals running around, which are that the big payment, the big tech companies will do this for us. Essentially, so Amazon or Apple or Google or somebody like this will impose a payment system through their software and hardware platform and people will just use it because it's very convenient. So essentially this is creating another oligopoly. It doesn't address any of the privacy concerns. If anything, it potentially makes them worse because the banks haven't really figured out how to use a lot of this information. They just now sell it to Google. But it's also, it is somewhat worse in the sense that it loses what kind of federation they already have. And it means to some extent even fewer points of failure. There's also another proposal out there, of course. It's the blockchain world with bitcoins where the main feature that is often proposed is saying well, we don't need all of this banking regulation. Interesting technology. It has a huge advantage that it's actually implemented in free software unlike most of the rest of our banking system. Try to get the source code for a visa. It's actually free software. You should look at it. It's a decentralized peer-to-peer payment system. But as any payment system, it has to solve a simple problem which is Byzantine consensus. We have a bunch of parties that are possibly ill-behaved, very likely malicious because it's about money, and they have to agree on our balances. That's Byzantine consensus. We have to have an agreement among parties that are not necessarily trustworthy and they have to agree on who has how much money. And that's fundamentally an expensive problem to solve. And the Bitcoin people solve this by tying initial accumulation. How do I distribute bitcoins initially by solving this consensus problem? Yeah. So the idea was to make it competitive for adding new transactions to this ledger. But of course, this results in an extremely expensive system. And even if you could somehow solve the proof-of-work problem, just the distributing all the information to some fraction, the substantial fraction of the nodes is extremely expensive. So even just the blockchain itself, the scaling problem is already there even if you can magically make the proof-of-work go away. So it's extremely expensive banking. And of course, the other thing is... Here's the example of it being extremely expensive. The current average transaction value on the blockchain is about $1,000. This is not being used for normal purchases. The transaction fees for a transaction or the average transaction fee is something like $3 a transaction. If you include the mining reward, so effectively how much carbon dioxide is being burned per transaction, you get to like $3 per transaction. And it will be worse in the future. Yeah, it has been worse in the past, too. But the other thing is it doesn't solve the privacy problem. So on Bitcoin, all the transactions are public and linkable. So the state can trace them. They might be able to find out who your account is. They might not. So we neither have the strong accountability where I can say, okay, this is not going to be used for illegal things. So it's kind of great for extortion. On the other hand, as a citizen, if I use it, there's no guarantee that the rest of the world will forever what everything I've done on Bitcoin is about. So of course it has been enhanced with laundering services to better protect our privacy. And there's also cryptographic attempts to enhance it. The strongest of which is the zero-cash system, which uses some fairly advanced cryptography to hide the identity and the value of transactions. It works... I think a zero-cash, poor transaction, an anonymous zero-cash transaction takes about two minutes on your computer just to set up the transaction to do just the very heavy-duty cryptography to get it ready to go. So it's a very advanced crypto, but it's slow. So right now we basically have two choices. We can have a libertarian economy. Great for extortion, money laundering, all of these things. No regulation. And rather expensive. Or we can have this total surveillance apparatus built by the credit card system. Which one do you pick? Well, we try to provide you with a third choice, namely Nutala, which is based on an old idea of digicash, but with a bit more modern cryptography added. That's supposed to provide a privacy-preserving system. So when you spend money, you have privacy. But when you receive money, we call it taxable because your income is visible to the state. So the state can say, was this a legal transaction and did you pay your taxes on it? And of course, we want to make it practical and extremely efficient compared to all of the other solutions so your transactions go over quickly. All right. So we're going to be using electronic coins stored in wallet software, which will be an extension in the browser or something else. We're effectively going to act very much like cash and we'll be paying in existing currencies, so Euro, US dollars, or bitcoins if you want to have. You can use this to make much cheaper bitcoin transactions. So like a side chain. And it's also because everything will be free software and reasonably straightforward. It will be relatively easy to roll out a... roll this out for some sort of regional currency or something else. Any kind of thing where you need some sort of transaction system, whether in regular money or funny money. The high level view of the system is you have the exchange, which is like the payment service provider, which allows the customers to withdraw coins using a process involving blind signatures. So the exchange does not know which customer got which coin. The customer can then spend the coins at merchants have to pretty much immediately online deposit the coins at the exchange. So because this last leg here has to be done online, this is only an online payment system. It will not work if you're offline in the sense of you can't talk to the exchange. Of course it can work if you have a community and the rest of the world has gone dark. You can still pay within your community if the exchange runs within your community. All right, so we're building on... So the idea is we'll build on top of... We use the existing wire transfer network. There can be some aggregation in this or whatever. So the general idea is we have a customer and they want to be able to make purchases. So what they do is they first create an account with some exchange, install the wallet software, create an account, and then what they do is they tell their bank to fund this account by doing... In the US this would be an ACH payment. In Europe it would be a SEPA payment. SEPA payments are I think about four cents if you buy them for the way companies buy them. And for most customers, most SEPA payments, at least as far as I know in Europe, SEPA payments, the cost tends to get hidden these days so you don't see it. Okay, so that's... Once the money has arrived at the exchange, then the customer can withdraw a coin, their wallet will withdraw coins. And these coins are blinded so the interactions that they're doing here will be cryptographically unlinkable to whatever else they do in the system. And while the coins exist, effectively exchange has an SCO account within the banking system to kind of store the value in the existing banking system. So when the customer finds some merchant that they want to buy something from and they spend the coins, the merchant immediately runs this deposit operation with the exchange and the exchange may or may not aggregate those payments but at some point they pay the merchant's bank account and the... But the merchant knows as soon as they've done the deposit operation successfully that they're going to get paid. And... Yeah, yeah. Okay, to make it a bit less abstract, Serenity is now going to give you a demo of the system, a live demo against the real system. You can also go to this web page with an appropriate browser and do it yourself there. Okay, my mic is on. I don't want to test that. So first of all, I'm gonna install the wallet. Nope. What? Demo. Wrong link. Click on introduction. Okay, installation is compatible. Audio torson.  You can either log in if you already have an account or register if you don't. But... By the way, if you want to get this account, use the name Shash 2017, password is the same. Like everything else here. It's Shash 2017. Never. Money money for this. It's just because for data demonstration. Torsten, you have to say what you were doing. You accepted the fees. I accepted the fees to withdraw some coins. Now 4 minus 4 equals 0, obvious. Withdraw approved. Now you can see in my wallet if I click here, 19.8 kudos. This is just the current demo currency. Meaning that the withdraw fees was 0.2 kudos. Now we're gonna go to the easy shop or whatever it's called I don't remember. And we're gonna pay for a chapter of Richard Stallman's book. Free softwares, whatever it's called. I am not gonna bother reading right now. The payment came up just automatically in that particular setting the payment came up automatically. In case you missed it, you just paid, right? It's easy to miss. Torsten, can you do it again slowly? Because I think it's a bit too fast for the audience. Okay, then I'm just gonna click on the other one. Confirm payment. Here's the contract being shown. Sorry. Slowly, Torsten. They used the credit card payments. They're supposed to take a couple of minutes. So a lot of why it can be this fast is because you're not providing any identity information. Wait, there's one thing left. Donate. Don't do the donations, we don't have time. So I'll just point out that much of why it can be that convenient is just because we're not providing any identity information. You don't have to think about do I want to type my name into this website, you just go. I was actually asked by a representative of Deutsche Bundesbank that we're going to require two-factor authentication in the future. Where do you do two-factor authentication? I said, well, I own the hardware. It's my notebook, one factor. And I have my username and password to my account on that machine. That's the second factor. I mean, it's like cash, basically. That's the point. Okay, so what are the impacts of this? So first of all, it's finally a free software payment system, right? And because your income is going to be transparent, it's going to be very hard to be corrupt in that kind of system, right? I'm sure I can no longer say, you know, I've never got this money. It's highly efficient. We need a couple of cryptographic signatures, a couple of database entries, so transactions, as you see, they go through really fast, you know. And of course, very comfortable to use because you just, you know, need one mouse click. We had people say it's maybe a bit too easy to spend your money with the system. You might get rid of all of it. So it's your privacy. And we're planning on using it to also provide accountability on network usage so we can use micropayments. So you want to access my web service? I'm currently under attack. Attach a couple of, you know, fractions of a cent. And then I don't have to show you a captcha, for example. Yeah. So we mentioned something about regional markets and we'll say a little bit more about that. It can also be deployed in a variety of special situations for kids and other things like that. It should be better for competition as well because since the exchange software, everything is GPLed, we, the ideal would be that there will be multiple competing services that can lower prices this way. The other thing is the system is good against discrimination and for accessibility because the exchange does not have a contract with the merchant beforehand. The exchange says I'm going to issue coins at whatever merchant you're going to spend them. There's no protocol where the exchange can say I refuse to deal with WikiLeaks. You can't. The regulator says issue coins, you better pay them up. So because there is no such prior agreement, you can't discriminate. You're going to really establish banking again as a neutral thing. Like network neutrality, we need banking neutrality.  We need a neutral platform. And the protocol ensures this in this case. Because it's free software, the wallet can be there to educate you about your expenses. It keeps a transaction history for you. It can help you analyze where you spend your money. It can warn you about your spending too much. Because it's a free software wallet, we as a community can enhance these features and make sure that the wallet provides us with tools for financial responsibility, not for a way to drain us of our money as quickly as possible. And of course, because it's free software running on my computer, I can tailor it to my needs. So if I have accessibility needs, I might have a wallet that's really tailored to my specific abilities and usability requirements. Want to say more? No. Okay, let's go over some use cases. First, use case. Today, when you're a journalist, you're typically working in some big corporate structure. And the big corporate structure is there because your main source is not selling your articles, but advertising. And that means, of course, that the publishers also have to track the readers so that they can tailor the advertisement. So we have, on the one hand, the drive, we need to understand the readers so we can advertise to them. And then, of course, we have the second problem, which is that we have advertising content and journalistic content. They're really next to each other, produced by kind of the same entity. So is it now advertisement or is it extra journalism? Very hard to distinguish the two. Yeah, so the idea with Taylor, what happened is we can do one-click micropayments like we just showed with the demo. So you can simply run a blog and get paid. You don't need a... The payments can be quite small because the transaction fees can be really small. The... You know, it's relatively easy to set up. They won't be... If you do it in this kind of, in this form, linked to any sort of other corporate apparatus or advertising, and your readers can remain anonymous, which seems like it might be relevant in the case of publishing journalism. Yeah. In other cases, we have lots of people that today are effectively discriminated against by the banking system, either because they don't have the right papers, they don't have an address where they can be registered. This in particular applies to refugees, but also, of course, to kids. And so if you have these non-bankable people, well, they can't use money as an easy way of doing exchange and running an economy. As a result, they are mostly directly dependent on Direct8. There's not really companies that are running in the refugee camps, even though there's a population that could work. The fact that we're excluding them from our monetary system means that they can't easily work in the way that we usually work. And the result is, of course, that they are highly dependent on this aid. So, with Holler, it's relatively easy to spend up a local currency, or to provide some sort... You can have an NGO can provide either its own currency or local currency, or something else like euros as some sort of basic income directly to a group of people, a group of refugees or whatever that are running the software on mobile devices. Then you can sort of create a small economy in that environment, use it with where you have... If necessary, you have taxation for whatever the local businesses there are, and you can start to actually use that money to fund a local government. You can have the sort of mechanics of Western banking sort of just up and running in this aid. And so the next camp, I expect us to run a government here, right? The badges should be a good starting point. Okay, last use case. Well, today, as you might have seen in Anani's talk, we have pretty easy privacy providing authentic encryption for email, which is great. It's free software. It's easy to use because of this encryption available for all the platforms, including the proprietary ones. And the great thing is that the spies will no longer be able to inspect the content of our emails, and the not-so-great thing is today we're relying on spam filters to inspect the cons of email to suppress the spam. Well, if you have effective end-to-end encryption that becomes universal, the spammers will eventually also start to encrypt emails. First, we will hear all of this as a great success. And then once we get 100,000 of those, we will say, oh, that's a problem. One thing that you could do if you want to, if this becomes quite the same, if encrypted spam emails become a serious problem, is you could do peer-to-peer email behind payments in the email so you can include a taller payment in the encrypted message, and the sender attaches some payment, and then the receiver can simply grant a refund to the sender if they don't... The receiver's software can simply grant a refund to the sender if they don't click the junk mail button. So this could work. We haven't implemented anything like that, of course, but it could be done with the underlying... Basically, Adam Becks altered it of hash cash except for with real cash and without the proof of work.  Okay, let's move a bit on towards the technology, but we have to first explain a bit what taxability means in Taller. So the high-level idea is when we say taxable, when you're a merchant and you receive income through a system that's going to be visible from you depositing the coins at the payments of his provider at the exchange, and then, of course, they can say, oh, you got this amount of money. And the contract that you agree to with the customer is going to be embedded, the hash of that is going to be part of the payment so that later the state could come to you and say, what was the contract? What did you sell? Is it a VAT or is it income or whatever tax is applicable and check that? The exchange does not see the contract, only sees the hash of the contract because, of course, the contract itself is none of the business of the payment service provider. And because of this, the state can trace transactions whenever you receive money and then apply the right level of taxation. We don't say how high the taxes should be, but we just say the income is visible to the state who can see the banking system and controls it not to everybody, and therefore, the state can apply taxation. However, there are a couple of loopholes. Yeah, so there's a technical loophole that's kind of hard to avoid in any sane way where obviously if you take money out of an ATM, you can immediately hand it to somebody else and this is true for us as well. In this case, you're essentially doing the withdrawals for them. And that, in principle, there's measures you can imagine. If that actually becomes a problem, there's things you can imagine people doing to try and suppress it just by looking at the pattern of withdrawals and things like this. And the other thing is that's somewhat more interesting is there's nothing we can do to prevent transfer of coins amongst people that trust each other. So when we say that Taller is taxable, what we mean is that transactions between people that don't trust each other will be visible to the banks of the recipient of the money. If you're just transferring coins, if you're just giving coins to your brother, there's nothing we can do to stop you from doing that. That's perhaps, one way you can argue that this perhaps should be more liberal than it is in today's society, or that's a subtle point, we don't want to get into it. In general, we've met people who basically said all of these limitations actually features because you might want those. If I want to give my kid money or my spouse money, it might be a good idea for me to just be able to hand over the electronic coins and not have to have them pay income taxes on it. It doesn't make any sense. It's not economic activity as such if it's within a family. Let's talk about the crypto. The high-level point is we're using very, very old crypto as far as crypto goes. But of course, modern instantiation. So we use hash functions, blind signatures, no signatures, Diffie-Hellman key exchange and the cotton shoes protocol in modern instantiation, but they have well understood old constructions for crypto. This is important because some of the other projects in this area are used for other stuff that's like two years old and has not been as analyzed as well, I would say. All right. One thing we need that's kind of essential is what we call a denomination key. This is a key that represents a particular amount of money. This is a five-year-old note. It's a particular RSA key that the meaning of this is that the thing signed by this is a five-year-old bill. So we create... This is just an ordinary RSA key creation. We pick two primes, we multiply them, and then to get this end, the product of them is going to be part of the public key. We take the other token function of that product, which we can compute because we know the P and Q and now what we do is we pick this small e less than phi of n, which is usually around 65,000, and we invert it mod phi to the n, and then what we do is we publish e and n. So the private key of the RSA key is really d or in faster algorithms, d and p and q, all three together, and then the public key is this e and this pair e and n. So that e and n will be published. To make it a bit simpler, using pictures, we throw some dice, get some random numbers, create a public key which you're going to represent by a seal. That's signed by this public key, and we have a tool, which is the hammer, which allows us to apply the seal to objects. All right. So now we also need various signing keys. In particular, the merchants need to be able to sign that they're proposing a contract to a user. And this we do with the ECDSA, which is a particular elliptic curve signature algorithm. So essentially what happens is they pick a private scalar, actually something else, but actually something they hash into a scalar, but whatever, they pick a private scalar and they multiply it by the generator of the curve. To get a curve point that represents the public key for that particular merchant. The main upshot is you have some small value m that you created at random, and it gives you the ability to sign documents with that value. Right? So we also use elliptic curve signatures to create, where customers will use elliptic curve signatures with every coin that they buy from the exchange. And so they'll have a different small c, which is again a scalar on the curve, and multiply by that we get this big c guy, which we refer to as the coin's public key. So for each coin you have a private key and a public key. Again in pictures we just write this public key, this big c like a serial number on the coin, a bit hard to see here. And the small c gives us the capability of signing things with the coin. Then we're going to represent like with the seal. So I can sign things with coins. These are all the keys that we're going to use for now. There are a couple more in the actual system, but I think these are the main things needed for understanding the system. Okay, let's get started. Alright, so this is what's called how we do, this is blind signatures, this is how you would draw money anonymously. So what you do is your wallet will know this, will find or otherwise know the denomination key of the amount of the coin that value that it wants to withdraw. It computes one of these planchets. It makes up a private scalar, comes up with a big c, which is the curve point corresponding to it, the public key for that coin. And what it does is it takes, for technical reasons, a full domain hash of c, and that is the thing that is being, taking this full domain hash is the first part of the RSA signature algorithm. And so what it does to have the blind signature is it picks some blinding factor in the integers mod this n, and it exponentiates this to that e from the RSA, from the RSA setup, which is the same as encrypting it to this thing that you think of as a signing key, and then you multiply that by this full domain hash f.  Okay, so in pictures again, basically you make yourself a red number b, and you use to lock the planchette into an envelope that you can only open kind of with this b value, and otherwise I can send this envelope to somebody and they won't know what is in there. So they can't see in particular what the serial number of that coin is, because that's what I need to hide. Yeah, so now on the exchanges side what they do, so they receive this blinded planchette and what they want to do, this f' from the previous slide, and they also receive an authorization to take some money out of the balance that the user has given them, and so then what they do is they run the ordinary RSA signature algorithm which consists of just taking this f' and exponentiating it to d. And if you think about what that does in terms of the form of f', f' was f times b to the e, then d distributes over it, so you end up with just f to the d times b to the e times d. Oregon, put it more simply, you apply the hammer to the envelope without knowing what's in there and send it back. So on the user side when they get back this s' which had the form f to the d times b to the e times d, well b to the e times d is just b, so they can multiply it by b inverse and they get back a signature of the original guy. So this is how blind signatures work, it was David Chum that came up with this, it's 30 years old. It's exploiting the kind of homomorphic properties of RSA that we usually try and hide and usually try and avoid, and the only delicate parts of this are essentially how to preserve this homomorphic property and not create some other kind of catastrophes, and that was why we had that FDH back in the beginning, but that's another thing. Anyway, so the main thing is at this point the wallet has the coin and you saw this happening in the demo a bunch of times because 1980 is a bunch of coins in our case. Now on the web in the demo, the steps of course you have to authenticate yourself to your bank, tell the bank, send the money to the payment service provider, the payment service provider says, okay well this is my fee structure, how many coins do you want, you authorize the transaction with your PIN, TAN check and eventually you get your coins. So this is just the overall diagram for that interaction. Now the next step is of course to go shopping. So the first step is the usual thing, you build yourself some shopping cart at some shop and somehow agree with the merchant on what you might want to buy. Now at the time when you do the checkout, the merchant has to say well what payment method do you want. We offer two ways of doing this nicely. One you can with JavaScript detect that the TALA wallet is present. Basically the TALA wallet exposes one bit of information to the website namely I'm there or not. So in terms of fingerprinting it adds one bit to your profile unless of course TALA becomes universal which we all hope. Second possibility if you have JavaScript disabled all of the TALA payments work still with JavaScript disabled and you can still do something there because we have a CSS tag that you can set or not set to show or hide elements on the web page depending on the TALA wallet being present. So the TALA payment process works completely without JavaScript but of course you might do more fancy interactive stuff if JavaScript is there using this method. Then when you've decided okay the user should pay with TALA what you do is you send a 402 payment required HTTP status back to the browser. Who knew about 402? It's ancient right? And the only thing you have to do basically you have to add additional header XTALA contract URL which is an address where the wallet can obtain the contract in JSON format. Basically saying this is what you should pay for. And then the body you can do whatever you want to do in case something goes wrong like the TALA wallet isn't really there because you fail to detect it properly or somebody just directly access that web page and maybe you show your normal non-TALA payment process there.  Anyway on the cryptographic side once we have this proposal to do this the contract of course has to include a signature saying this is what the merchant offered me. So we have the proposal D here that's the JSON and we're going to sign it merchant key that we saw earlier that we did second in the list of keys and you sign it and send that to the wallet, right? All right so when the wallet receives this proposal which is signed by a merchant and the user actually clicks this pay button what happens is the wallet will send back the three things so it'll send back the signature S that the exchange gave it that it obtained from the S prime the exchange gave it on this big C and so what this signature says is that big C is a coin that represents five euros and then it'll use big C to sign this contract that the exchange gave it Now of course it's possible that one coin isn't enough to pay for a contract and then you just do it with a bunch of coins until they end up to the total value of the contract Then what does the merchant do? Well he basically checks is the signature correct? Yeah. If it's correct he passes down to the payment service provider the payment service again checks is the signature correct and have I seen this coin already? Has it been double spending? Has the guy tried to spend his money twice? If no, I'll accept it and tell the merchant it's all good signed the exchange If it's invalid I have to provide the old purchase as proof that it has been double spent Again here's the process in the WC3 payment interest group format you basically first negotiate what you want to buy you obtain the contract confirm that you do want to pay to the merchant who sends it to the payment service provider the payment service provider confirms it you tell the wallet, yep contract went through, by the way get your product, your business logic, your confirmation page here and then the wallet goes to that confirmation page again you've seen it happen Now this one little problem with this setup that we've described so far which is what if I want to buy something big not the 10 cent thing but maybe something for 100 euros now if I have coins and I want to be able to pay things for 1 cent and things for 100 euros I don't want to end up doing 10,000 transactions of 1 cent for a 100 euro transaction that would even with this system take too long because you have to do 10,000 signatures now of course I can give out different denominations 1 cent, 2 cent, 4 cent, 8 cent and so on but it's still of course a puzzle that I might have whatever a 5 euro coin but I want to buy something for 3 euros and I shouldn't tell the user well you have more money than what you want to buy but you don't have exact change so we can't handle it so how do we deal with giving change that's basically the main things that we improved over the original DigiCash now in giving change we have two key requirements so first of all we need the change to be when you obtain change whatever change the user obtains it needs to be unlinkable to this transaction because perhaps they like gave out their real name or their address or something like this in this transaction and so we don't want the coins that they get back from it to be linkable to it and we also want to maintain that it's tax this taxability property which we got sort of from the way the blind signature scheme works okay the key idea is basically when I sign a contract as a coin say I sign a contract over 3 euros with a 5 euro coin I say don't give the merchant the full 5 euros only give him 3 which means the exchange knows that on this coin there's 2 euros left and then I can later go to the exchange and kind of double spend the coin saying please give me change for the 2 euros that are remaining on that coin and then I get 2 additional say 1 euro coins right and effectively now the 5 euro coin is completely burned and that's good now of course there's a problem with that but let's first give you a bit more background so just this is it's hard to know how much crypto people are in the audience so this is what a Diffie-Hellman key exchange looks like so we have 2 parties and in the classical Diffie-Hellman there's 2 parties but whatever in whatever setting there's 2 private keys a C and a T and these are scalars for some elliptic curve and we multiply those by the generators of the curves and then we come up with big C and big T which are the points on the curves so these are the public keys and now this curve is an Abelian group which means that when I the order in which I add things doesn't matter so what I can do is I can take and I can take and I can multiply this little C the guy who knows the little C can multiply T by itself and I can add T to itself C times which is the same as C times T times G and this is Abelian so we end up with T times C times I can reverse the order of these 2 guys and that is the same as adding this big C to itself T many times so this is how Diffie-Hellman key exchange works if you want to have a simple idea just think of it as a lock with 2 keys if you have either of the 2 keys you can open it if you have both it's of course also awesome alright so here's our sort of strongman solution to this which we sort of mentioned already so we have a we have this partially spent coin what we want to do is we want to pull out a new key a new coin from the residual balance on that so what we're going to do is we compute this new coins public key and we pick a random blinding factor and from so we take again we take this FDH this hash of the new coin and we run through the ordinary blind signature algorithm from it and we request we request except instead of asking that the value be funded from some user's account we ask that it be funded from the residual value of some partially spent coin now the big problem was that I said I can't show that C new the new key right that is coming out of this process pretty much looks like the previous withdrawal process is actually owned by the same person so I could say okay I had 100 euro coin I want to pay him so what I'm going to do is I'm going to tell the exchange give me change for 99 euros and he creates the C new for the new coins which means he will own them only he has the private key and I signed the change request with my old key and I transferred the value to him he doesn't have to trust me he knows he has the private keys he generated them he never disclosed them to me he gets the signatures from the exchange so he knows he now has valid coins and he had this as income and the system thinks I got change right so that's what we have to prevent we have to make sure that the owner of C new is the same as the owner of C old but because we want to make sure that transactions are unthinkable we have to at the same time make sure that nobody else knows that this public key C new has a relationship to the public key C old right so keep them unlinkable but make sure they're owned by the same person is the idea all right so to do this okay so what will this so to do this we're going to use a a Diffie-Helman key exchange to derive the news the C new and the B new so okay so what do we do we we have our C old that's partially spent we now instead of creating the C new what we do is we create this little T which is also an elliptic curve scalar but and we compute a public key that corresponds to it and we compute this X which is the result of this Diffie-Helman key exchange and we run two key derivation functions on it of which give us a C new and a B new and then from C new we we again compute the key the the public key and we create this hash and we we recall and we blind it with the B and we request that we request that the exchange signs this that should be very confused here certainly because from the exchange perspective this year and what we did before we told you is wrong looks the same right both cases I get this envelope that I don't know what's in there so how do I know that Jeff how do I know that this process was followed the answer is we do it three times so we make up three of these T these T1 T2 T3 we do each of them getting a different Diffie-Helman key exchange result with the C old and we send all of them to the exchange and but then I can just cheat you three times well we're not going to give you three coins for the value of it only going to give you one and so the exchange picks one of these values that it picks one one two or three and what we do is we send back we send back the we send back the user is required to send back this private key for the big T for the other for the others and then the exchange can run through these derivations and check that for the other two that it didn't pick the user did the derivation correctly and if they did then they can run through then they can finish the protocol but that means I can cheat you one out of three times successfully just by guessing isn't that not quite cryptographic security Jeff? one in three times means that your tax rate will have to be more than 66% to be able to do any tax evasion with this so if my tax rate is 70% then you do it four times 80% five times the number of times I have to do this in the cut and choose protocol for same tax rates okay so I've done this correctly you've checked this and then I get my coin I've proven that I've done this correctly now at this point I could have still run this with the person who wants to invade their taxes it can still be that all of these transfer private keys were known to somebody else so I got the coin but I have to now still make sure that the new coin is owned by the same person so what the exchange does it says okay if somebody gives me the old coins public key I'm going to also hand out the envelope and the transfer public key it's just a little you know exchange volunteering some information that's usually pretty harmless and if I'm the one who owns the old coin I have the private key of the old coin I can also do the Diffie Helman with the transfer public key and I can also derive the new coin's private key and the blinding factor and can open the envelope so this basically means that the owner of the old coin has kind of a back door into the Diffie Helman and can also reconstruct the private key of the new coin this way and we know from the cut and choose that it was constructed properly which means that now if there were two parties both have all the private keys and signatures which means we've reduced this possibility of a transfer of money to this case where we're sharing private keys which we could have just done directly we're back in the situation where we trust each other in terms of who can spend it alright okay so we have this we so the customer asks the exchange to convert the new coin to the old key the protocol ensures the the new coins via this last step the protocol ensures that the coins can always be recovered by the old from the old ones and this implies that the new coins are in some sense owned by the same entity as they owned the old ones if where ownership is sort of determined by this possession of the key or the ability to get the key so we can use this protocol to give change we can also use it to give refunds basically if the merchant signs give the money back to the customer add it back to the balance of the coin the customer refreshes the coin and he has change has a refund if we have to expire coins we can basically say this coin would expire into years if you want to detect that it's about to expire it just runs the refresh protocol, gets a new coin and we can forget about the old keys don't have to keep an ever growing ledger like in bitcoin and of course if the protocol has an occurrence in a board situation where the network goes down and they need to remember I can also just say okay the merchant the transaction didn't complete but I can back out by running the refresh protocol and have my coin back in a new state that is fresh and unthinkable to the board of transaction so to compare the system with other things as you can see compared to cash you know we don't work offline we only work online the transaction costs are extremely low payments are extremely fast we do support taxation because income is very easily visible to the state we have anonymity for whoever buys something but no privacy for whoever receives money we of course would claim this is the most secure system of all of them we don't have conversion here saying you don't have to convert right with bitcoin you have to create a new currency here you can pay in euros, you can pay in dollars you don't add a conversion risk for the user or a conversion cost and of course it's a free software project part of GNU if you're interested we have all sorts of information lots of documentation and the source code we have relatively good documentation on the specifications for the protocols and things like this I'm not sure what it is I should mention this is a GNU package that is going commercial so we are also looking to build the business around it so if you happen to have a couple of million euros lying around please talk to us or run a bank, if you run a bank that's almost more useful a bank will be better, yes to conclude we have the choice, we can suffer mass surveillance from the credit card oligopolies or the big payment providers like Google Apple Pay and so on we can as a society engage in an arms race with unregulated blockchains and have our ransomware extort us or of course we can enjoy the benefits of cash like in India where they sometimes cash even for offline payments or you can help us build taller and establish a payment system that balances the social goals of transparency and privacy thank you I'm sorry any questions so Serenity is taking over my job so come on do you have any questions yes I would like to ask do you so the original Trump's e-scash has this nice property of if you spend twice the same coin that your anonymity gets revoked so there's a big problem with those schemes there's a huge literature on sort of expanding on those schemes the reason for doing that is to allow offline spending and specifically to allow the merchant to be offline so in our scheme the user can be offline much of the time the merchant needs to be online the reason we don't want to do anything like that is because if you think about just managing the system it's almost impossible to imagine that double spending will never happen like restoring from back up there's all kinds of failure modes where double spending is just going to happen by mistake so if you have that kind of system where you de-anonymize the user it's very the privacy properties for the user at that point are very hit or miss so it's really not acceptable if you want to say your system is really private so it's dangerous for privacy that's one thing but the other thing is from the business point of view if you double spend a coin you can also billion spend the same coin and now you're only a billion dollars if you double spend it now I have to go after you and recover the billion dollars that you obviously don't have so it's not like being able to de-anonymize you give me an easy way as the operator to get my money back so it's a huge business risk to de-anonymize and then go after the people and that cost we just don't want to pay one of the advantages of something like taller is because acting as a thin layer on top of a set of payments it doesn't it doesn't incur there's nothing like all of the nasty collection stuff that has to go on in a credit card and it's those things that initially made credit cards very expensive so we avoid all that and we don't have that initial that cost so this already seems really compelling for the retail scenarios where I've used Bitcoin so far it seems like it would be better for me but I do like one or two charge backs a year I like almost take a Kali in it it's my favorite thing about credit cards so would you come closer to the mic? if I had to choose between being anonymous and being able to do a charge back if the merchants screwed me and have the credit cards company like negotiate with me I'm not sure which one I'd pick I wonder if you thought about the charge back path and if you could factor it out of the crypto it sounds like I don't do as many charge backs as you do but I have done them at a few points in my life and there's a very nice feeling of I'm in charge when you do that the there is a system for refunding and the merchant has to choose to refund in the scheme that we have and the so the mechanics of doing a refund work and in fact the refunds can be done anonymously so the customer can get their money back without having to reveal anything about their identity in the scheme the way we envision it working is that the merchant would have to authorize the refund because there's simply not money in the system otherwise it's not impossible to imagine that the exchange could do some sort of arbitration there but now you're asking the exchange to do this arbitration process and realistically all of the schemes that people are seriously talking about deploying that's what they're getting rid of is this arbitration process Apple Pay all of these things it's that the 3D secure all of these things the whole point is to reduce the customer's ability to object so that there's less risk for the merchant there the good thing is you have cryptographic proof of the operation and if you want to have this kind of arbitration process you could of course say I'm not going to pay the merchant directly but some arbitration process operator that is going to hold the funds in SQ until I decide it's all good so that would be a separate service just if you really need this arbitration at the extra cost it imposes then buy it and add it on top as an extra layer I guess you're saying that in the architecture you proposed the exchange could unilaterally decide to do a refund no you have the signatures it can give you back the money it can put the money back on the coin you get the signature from the merchant that authorizes the refund and you have no way of knowing who is the right customer but ultimately it's the exchange who decides what the money is on the coin the exchange shouldn't be an arbitration if you want an arbitration service build it separately would be my answer question hello hello my name is Pavel I have a bit of ideological question I'm crypto anarchist so it means that I believe that cryptocurrencies are here just to provide us completely new kind of personal and economical freedom and this is not only me but Satoshi thought the similar idea I mean the control not only over corporation but even the government so when I first heard about Anonymous Taxable Money it sounded for me like a big joke but so my question is you have a lot of different competitive cryptocurrencies and my question is how do you want to persuade people to use a friendly cryptocurrency without coercion this is not a cryptocurrency this is a transaction system ok but anyway so my question is how people will use the system without law or without forcing people to use the system people use credit cards without law people use PayPal without law why shouldn't they use Tala without a law it has advantages for them in terms of privacy I should point out when we say that it's taxable what we're doing is we're converting we're saying that our system does not reduce the government's ability to monitor transactions relative to what the underlying transaction system provides if you run Tala on top of Zcash you will have very cheap transactions and nothing will be traceable but for example if you run on top of SEPA payments it will have the same properties as SEPA payments in terms of taxation if you run on top of Zcash it will have the same properties as Zcash we have to stop sorry to interrupt you no more? we'll be here for the rest of the day please come find us and we'll be happy to answer your questions thank you


Yes, he had used up his chances. On the island of EA before a burst of Jap machine gun fire, Ernie Pyle, America's best-loved war correspondent, died as so many American boys he'd written about. Ernie Pyle was killed in action. The national broadcasting company in cooperation with the Council on Books and Wartime presents Words at War, dramatizing the most representative books to come out of this great world conflict. Our original schedule called for the presentation of another book, but the death of Ernie Pyle in the Pacific made his brave men the timeliest program we could bring you tonight. And so we bring you the stories Ernie Pyle wrote about the American fighting men, the songs they sang together and loved so well. Here is a tribute to the little guy who held the love and affection of every American soldier he ever met, his Ernie Pyle's last book, entitled with his simple eloquence, Brave Men. What is it like before a battle? What do they think about? Well, they're afraid, but not afraid of the physical part of dying. That isn't the way it is. The emotion is rather one of almost desperate reluctance to give up the future, to give up such things as seeing the old lady again, of going on to college, of getting married, of holding on your knee just once the kid you've never seen, of becoming the champion salesman in your territory, of driving a coal truck around Kansas City once more. Yes, even of sitting in the sun again on the south side of a house in New Mexico. It's these little hopes and ambitions for some bright tomorrow that makes up the sum total of the worry and anxiety in the hearts of the waiting men. I think you can ever fully understand the ties that grow between men who live savagely together, relentlessly communing with death. They're ties of great strength. There's a sense of fidelity to each other in a little core of men who've endured so long and whose hope in the end can be so small. Lieutenant... Yes, Sergeant? Well, I'm supposed to go back to rest camp tonight. I know, Buck. But we're due to attack tonight. Yeah. Well, Lieutenant, well, I don't think I'd better go. I'll stay if you need me. Of course I need you, Buck. I always need you. But it's your turn and I want you to go. Well, I'd just as soon stay, sir. I know, but you're going. That's an order, Buck. Yes, sir. Some cowboy had a long... This was in Italy. Sergeant Buck, a cowboy from Idaho, came back to the little group of old-timers with whom I was standing. He thought he was leaving forever. I guess I'll be going. Good luck to you all. Thanks, Buck. Get yourself a good rest. Yeah, I don't want to be gone five days. Sure. You'll be back before you know it. Yeah, well... So long, everybody. So long, kid. And... And... Well... Good luck. Good luck to you all. Thanks, Buck. Thanks, Buck. Take me back, take me back. The vallies were swabbed in a dismal mist. The artillery of both sides flashed and rumbled around the horizon. The encroaching darkness was heavy and foreboding. I walked with Buck to the waiting truck. He kept his eyes on the ground. And I think he might have cried if he'd known how. Yeah, Buck, this will be the first battle I ever missed with this battalion. Yeah. I sure do wish him luck. Well, they know that. I feel like a deserter. I can lay down on the ground with my other friends waiting for the night orders to march. I lay there in the darkness thinking terribly touched by the great simple devotion of that soldier who was a cowboy. Thinking of the millions of people far away at home who would remain forever unaware of this feeling of the soldier for his comrades.  What? I'm going to fix it so my kid won't have to fight in the next war. How are you going to do that? Well, I'll tell you.  That ought to break down the arches. Then I think I'll feed him a little ground glass every now and then to give him a bad stomach. That ought to make him 4F all right. Yeah, and I'll make him read by candlelight to ruin his eyes. When I get through with him, he'll be double 4F. Joe, if I didn't know you so well, I'd say you don't like it over here. Oh, you know me better than that. I just love this nice mud in that German artillery. Listen, if I ever get home, you'll have to catch me to bring me back again. Go on, you'd be home a couple of weeks and read about us over here. Remember these bull sessions? You'd bust out ball and you'd be so homesick. Yeah, well, just give me the chance, that's all. Just give me the chance.  Oh, the guns, guns and the pretty, pretty huns, what a love. But they tell me that a lot of American soldiers who return to America do get homesick for the front.  I'm sure it's true, but I know a lot of soldiers who would like a chance to put the theory to the test. Behind me is a distinguished and unbroken record for being sick in every country I ever visited.  Well, they established me in a clearing station and finally decided I had battlefield fever. You don't die of that. You just think you will. As I began to feel better, I became aware of the wounded and the dying men who were constantly being brought into the tent. I feel okay. I think I'm going to make it, Doc. Of course you will. Are we all right? Let me go. I can walk all right. Here you go. The bed's here. Well, now I want to go to bed. There's nothing wrong with me, Doc. You don't call this little scratch anything. Let me out of here. We've got to take care of that wound, son. We're going to send you back to the hospital. I don't want to go to any hospital. I want to get back to my outfit. You wouldn't do your route for any good right now, son. You go on to the hospital. I've got some good-looking nurses there. I don't care about any nurses. I want to get back to where I belong. Now, take it easy, soldier. Take it easy. It was flabbergasting to me to lie there and hear wounded men cuss and beg to be sent right back into the fight. Of course, not all of them did that. It depended on the severity of their wounds and their individual personalities, just as a wooden peacetime. But the main impression I got from all the wounded was their wonderful spirit and the thoughtful and attentive attitude of the men who cared for them. Well, eventually, after having indulged myself long enough to keep up my sick record, I got back to the front. Front-line conversation covers almost every topic in the world. You know something. For 25 bucks, I'll eat a double-edged razor blade. Now, what you think of that? I wouldn't give you too much. Now, you can't do it anyway.  How do you do it? I just chew them up. I haven't got 25 bucks. Well, you could all pitch in. Look, I'll take a double-edged razor blade, chew all up and swallow her down. Now, what you say? Nah. Can you really do it, Sam? Sure I can, Ernie. I used to do it all the time before the war. I was offered a job in a carnival. Well, is that so? Ernie, how about you putting up 25 bucks? No, Sam. I think I'll wait and see it for two bits at the carnival. Oh, it's worth 25 bucks to see a guy eat a double-edged blade. Hey, I wonder if we'll ever get those galoshes they promised us. They've been promising us galoshes for a month. What do you all with galoshes? To keep my feet dry? My feet haven't been dry for six weeks. Take a drink of that lousy cognac they sell in Naples.  No kidding, though. I'd sure like some galoshes. Oh, forget the galoshes, will you?  Well, what's the matter? You got to talk about something. Anyway, it's not civilized to go around with your feet wet for six weeks. What do you mean civilized? What's that? Back home, we thought we were civilized because we took a lot of baths. I haven't had a bath in two months, and I don't feel any different. Maybe people take too many baths anyway. Maybe they do. I dreamed about baths. But when I got home, I'm almost ashamed to admit this. I didn't average more than one bath a week all the time I was there. Maybe what we're fighting for is the right to be as dirty as we please. So it's me. It always rains in the infantry, but we never take a bath. I found a hunk of soap one day, but the dirt began to laugh. I took a walk along the historic coast of Normandy after D-Day. It was a lovely day for strolling along the seashore. Men were sleeping on the sand, some of them sleeping forever. Men were floating in the water, but they didn't know they were in the water, for they were dead. You know, on that beach lay expended sufficient men and mechanism for a small war. And they were gone forever now. And yet we could afford it. We could afford it because we had our toe hold. Now we lock with the tanks and the mortars, some soldiers and a law. There were soldiers, packs, socks and shoe polish. Sewing kits, bibles, letters from home. Snapshots of wives and sweethearts staring up at you from the sand. Always there are dogs in every invasion. There was a dog on the beach now, still looking pitifully for his masters. He barked at feeling that every soldier who approached suddenly wronged. He went with them for a few feet and then, sensing himself unwatered, he'd run back to waiting vain for his own people with his own empty boat. Where the sand is our tombstone. Where the water is our graveyard. Where our bodies are like driftwood. The long ways from home. The strong swirling tides of the Normandy coastline shifted the contours of the sandy beach as they moved in and out. They carried soldiers' bodies out to sea. And later they returned them. They covered the heroes with sand. And then in their whims they uncovered them. They walked around what seemed to be a couple of pieces of driftwood sticking out of the sand. But they weren't driftwood. They were soldiers two feet. The toes of his GI shoes pointed toward the land he'd come so far to see. In which he saw so briefly. Why don't you tell them, Pyle? Why don't you tell them back home what it's really like? All they hear about is a lot of victories and glory stuff. They don't know that every time we advance somebody gets killed. Why don't you tell them? I told him that was what I tried to do all the time. See this soldier was fed up. His outfit had suffered heavy casualties. He was exhausted. He was filled with bitterness. Yet a few days rest and take it all out of him. He didn't want any credit or glory for himself. He just wanted to be sure the folks at home realized that men were dying. Some folks at home keep thinking of steak while the bullets they give us a belly. Oh, my gosh, a mine. Where? I don't see it. It's not a mine. Look, it's a little baby rabbit. A rabbit? Hey, don't ever do that again. I thought it was stepping on a mine. I'll say he's a cute little fella. Yeah, yeah, yeah, he's cute. But look, Bill, don't ever do that again. See? Yeah. Hey, this little fella's hungry. I'm going to take him back and get him some canned meals. You'd better leave it here.  Stranged little things happened on the battlefield. Private Bill Westcott found a little rabbit. He fed it tenderly through an eyedropper. There was quite a little rabbit at that. It hopped around everywhere after Westcott and when the distance got too far, it would go hoppin' back to the pup tent and snuggle up in Westcott's blanket. All the boys were crazy about it. Then, after about a week, we found the little rabbit dead on the grass. Private Westcott, whose own life was in the balance every day, felt awful bad about that little rabbit. It was raining heavily. We were all soaked through. We were on our way to clean out an enemy's storm point. The young lieutenant kept barking his orders. Spread it out now. The men didn't talk among themselves. They just went. They weren't heroic figures as they moved forward a few seconds apart. There was a confused excitement and a grim anxiety in their faces. Spread it out. Come on. Spread it out.  They weren't warriors. They were American boys who by mere chance of fate had wound up with guns in their hands sneaking up a death-laden street in a strange and shattered city in a faraway country in the driving rain. They were afraid, but it was beyond their power to quit. They had no choice. Hey, Ernie, raise your rifle. The correspondents can't carry rifles. In the national law. Sounds like a silly law if you ask me. Hey, I used to read your column back in Cincinnati, Ernie. You did? We're pals, then. Ernie, could you put my name in? I mean, the family would get a big kick out of it. Sure. Let me get the name right. Here, you hold my helmet over the pass. Sure. Thanks. Go ahead. Private First Class. Wait. Cincinnati, Ohio. Yeah. Even with the bullets winding down the street, the soldiers were eager for me to get their names so that the folks back home would know they were in this. I ducked from one doorway to another and named many names they could. Names of the actors in one little drama of the war along the rain-soaked street of the French village. Not much glory in the job they were doing. For as my favorite song in theirs puts it, they've got no time for glory in the infantry. They've got no use for praises loudly sung. Oh, they've got no time for glory in me. Oh, they've got no use for praises loudly sung. But in every soldier's heart in all the infantry shines the name, shines the name of Roger Young. Caught in ambush lay a company of riflemen. Just grenades against machine guns in the glue. Ambushed till this one of twenty riflemen. Volunteered, volunteered to meet his doom. Stood the man like the everlasting courage of the infantry. Was the courage of private on the island of New Georgia in the Solomon's. Stands a simple wooden cross alone to tell. Eat the silent coral of the salt. Sleeps a man, sleeps a man, remember. Oh, they've got no time for glory in the infantry. They'll settle for a mention in a guy's newspaper column just so the folks at home will know. Now a final story. I've told you of the feeling soldiers who faced death together have for one another. A feeling those who stayed at home will never be able to comprehend. Well, this takes me back to Italy and to Captain Henry T. Wasco of Belton, Texas. I have never crossed the trail of any officer so beloved by the men under him. After my father, he came next. He always looked out for us, always went to bat for us. I never knew him to do anything unfair. I was at the foot of the mule trail the night they brought Captain Wasco down. The moon was nearly full and you could see far up the mountain trail. Dead men had been coming down the trail all evening, lashed on the back of mules. They came lying belly down across the pack saddles. The heads hanging down on one side and they stiffened legs, sticking out awkwardly from the other. I don't know who the first one was. He feels small in the presence of dead men. You don't ask silly questions. This one's Captain Wasco. The unburdened mules moved off to their olive grove. The men in the road seemed reluctant to leave. They stood around. I could sense them moving one by one close to Captain Wasco's body. Not so much to look, I think, as to say something in finality to him and to themselves. I stood close by and I could hear.  That's all he said.  I think he was an officer. He looked into the dead Captain's face and then he spoke to him as though he were alive. Sorry, old man. Then the soldier came and he stood beside the officer and bent over and he said very tenderly, I sure am sorry, sir. The first man squatted down and took the Captain's hand. He sat there a full five minutes looking into the dead Captain's face. Finally he put the hand down. He reached over and gently straightened the points of the Captain's car and then he sort of re-arranged the tattered edges of the uniform around the wound and then he got up and walked away down the road in the moonlight. I'm just a fool in this world of hope. Such is the powerful fraternity in this ghastly brotherhood. Something that only our fighting men will fully understand. How thousands of these men will be returning home before long, they'll be changed. They'll have to learn how to adjust themselves to peace and all of us will have to learn how to reassemble our broken world into a pattern so firm and so fair that another great war cannot soon be possible. Tell the simple truth most of us over in France don't pretend to know the right answer. All we can do is fumble and try once more. Try out of the memory of our anguish and be as tolerant of each other as we can. He didn't want to go. He hated it. War sickened him and made him afraid. When he came back from Europe he said that if he saw one more dead man he feared he would lose his mind. He said this would be his last invasion. He probably meant it. But if he had lived it wouldn't have been his last invasion because although Ernie Pyle freely confessed his fears and his horror of killing he would go along with the American boys who had no choice but to go where they were ordered. Yes, he wrote his wife and this would be his last invasion. After this he would write stories from headquarters. But no GI believes he would have done that. Ernie Pyle would have gone on as long as there was one American boy who had no choice but to go on. The GIs who loved him went out in the face of enemy fire to bring back the body of Ernie Pyle from the spot where he had fallen. And the GI fashioned a wooden coffin for Ernie and laid him beside his fellow fighting men. No need to write an epitaph for Ernie Pyle it has been written by a GI on a crude wooden marker that stands over his grave on the desolate aisle of EA near Okinawa. It reads simply at this spot the 77th Infantry Division lost a buddy Ernie Pyle April 18, 1945 Oh Georgia in the Solomon's stands a simple and cross alone to tell that beneath the silent coral of the Solomon's sleeps a man sleeps a man remembered In tribute to the memory of America's best-loved war correspondent Ernie Pyle Words at War has presented a dramatization of his last book Brave Men. The radio adaptation of Brave Men by Ernie Pyle was by Gerald Holland Carl Swenson was heard as Ernie Pyle others in the cast were Martin Wolfson as narrator Jim Bowles Walter Kinsella Paul Mann, Larry Haynes Jeffrey Bryant and Carl Emory Our ballad singer was Tom Glazer Organ Music was by William Meadier Words at War is presented by the National Broadcasting Company in cooperation with the Council on Books and War Time Next week at this same time a dramatization of another important war book This is the National Broadcasting


Hey, this is Brett and this 2020 Toyota RAV4 XLE is stock number 12103ZB. We are here at Summit Automotive in Fond du Lac, Wisconsin, near New and used SUV headquarters. This 2020 Toyota RAV4 has the 2.5-liter four-cylinder engine, puts out 203 horsepower, it's going to get you 33 miles per gallon on the Highway 27 city. And this vehicle is 100% ready to go, it has a full safety inspection by our service shop, has a fresh oil and filter change, all the fluids have been checked and topped off, and is all ready to go. We're going to go all the way around in this video, inside under the hood, start it up. Midnight black metallic is the color and we shoot all of our videos in 4K, so if you have HD capabilities on your computer, tablet, smartphone, or television, I highly recommend turning them on right now because it is your best way to check out the quality, condition, and cleanliness of the vehicle before seeing it in person. And if you like how we do things here at Summit Automotive in the upper right hand part of the screen, consider clicking the subscribe button to our YouTube channel. And if you do that, click the bell notifications and you'll get updates on the videos we do each and every day of our new and used inventory here at Summit Auto. This one comes with the 19-inch painted alloy rims and it has Yokohama Avid GT tires, these are 235-55R19s, and they have just about half the tread left, a little bit under. Front fender is in excellent condition, didn't see any major dents or dings on there, it does have the LED headlamps and the factory fog lights. Front bumper is in very nice condition as well, I didn't see any dents, dings, or cracks on that. And the hood is in very nice shape as well, didn't see any dents or dings on there. And around to the passenger side, front fender is in excellent condition. This is one of my favorite colors and I'll show you in just a second why. And the passenger side rim, no scuffs or scrapes on there. So midnight black metallic actually has a lot of metal flake in it, it's got a lot of dark blues, a lot of bright blues, and it's just a really sparkly paint. So it's really a cool color on this vehicle. But as you go down this side of the vehicle, take note of how clean the body is, how reflective and mirror-like that paint is. We take these HD videos so if you are far away, or even if you're close buying, just cannot make the trip down, but you're still interested in purchasing the vehicle, you can see the vehicle, hear the vehicle, and have confidence in what you're looking at before you even get here. So when you do get here, there's absolutely no surprises and you can make a smart and informed buying decision from wherever you're at. And if this video helps you make that decision, let your salesmen know that you saw the video, that it was helpful, and that Brett sent you. Back rim is in excellent shape as well, and the back tires have just about as much tread as the front tires. Coming around to the back of the vehicle, you'll notice that it does have the dual rear exhaust, the chrome tips, and that this is an all-wheel-drive vehicle. You also get LED tail lamps, and the rear gate is in fantastic condition. This is a power lift gate, so that goes up like so, factory all-weather format, and that all-weather stuff goes on the back of the seats as well, and you do get a JBL subwoofer back here. I believe this one comes with the spare tire and jack tools as well. And to get this rear gate down, press this button right here, and it'll come on down like so, and that works nicely. Coming around to the driver's side, rear quarter looks really good too. Didn't see any dents, didn't see any dings. Paint is very nice and glossy, and for full disclosure, this back rim is in very nice shape as well. Down the rest is side of the vehicle. Doors look really good. You do get the blind spot monitoring and built-in directional signals on those mirrors.  There are no rips, there are no tears on these seats. They are in very nice condition. Smells very clean inside this vehicle as well. You get driver's seat lumbar and power seat, all-weather floor mats. Down here you get your heated steering wheel, power lift gate. Must be a heated windshield element to it. Auto headlamps, or auto, those might be auto brights. Power windows, power locks, power mirrors, and memory driver's seat. We'll hop inside and check out the miles, information center, and radio. So you can see that this one has 41,606 miles. You do get a time display, distance to empty, trip summary, all that good stuff. Instrument cluster is very nice and clean. Comes with the heated leather-wrapped steering wheel. On the right side we have forward collision warning, lane departure, information center controls, cruise controls. On the left side we have Bluetooth and audio controls, and more information center controls. We'll check out the radio here. This is the JBL touchscreen. This one has AM, FM, and SiriusXM radio capabilities. I also believe it has projection capabilities where you can project your cell phone to the screen. And if we go to audio, you've got AM, FM, Sirius, and Bluetooth. And then if you go to the home, you have that.  But anyways, you can project your cell phone to the screen. And then you can, if you've got a nav system on your phone, you can project it to the screen. And it's like you have nav right in the screen. So that's pretty sweet as well.  Does have a USB jack in there. This is your eight-speed automatic transmission. Eco mode, normal mode, sport mode, snow, sand, mud, rock, and dirt, all the different modes that you can do with this all-wheel drive system. There's your keyless entry. Pass and recite format and seat are in excellent condition as well. I didn't see any rips or tears on there. And it does have the power sunroof. You get map lights up there and sunroof controls. We'll take a quick look at the back seats and then check out, start it up and check out under the hood. Back seats are just as clean as the front seats. No rips, no tears back here. It does have the latch child safety system for any child car seats you may have. Very nice. You get the all-weather floor map back here. Looks like you get two more plug-ins here as well, two more USBs. And very nice and clean. Back doors look really good in. You do get child safety locks on the back doors as well. Bottoms of the doors all look pretty good. And we'll start it up and take a look under the hood. Starts right up. No check engine lights or anything like that. You do get an outside temperature display as well. I'm going to show you the backup camera as well. That's working nicely. Let's take a look under the hood. I would personally like to thank you for checking out the video today. And hopefully from this HD video, you will have been able to verify the quality, condition, options, and cleanliness of this vehicle inside and out. And under the hood, one second here. You have the 2.5-liter four-cylinder engine. The engine bay is very clean, runs very smooth. Once again, this vehicle has been fully safety and inspected by our service shop. It has a fresh oil and filter change. All the fluids have been checked and topped off. And this vehicle is 100% ready to go. There is your emissions sticker. And I would highly recommend this vehicle from a quality and condition standpoint. And to see more pictures of this 2020 Toyota RAV4 XLE in midnight black metallic, you can go to that website right there, www.summitauto.com. Full pictures and descriptions of every single vehicle from two locations, all at summitauto.com. And if you'd like to check out more HD videos, you can go to youtube.com slash summitauto. Remember to like, subscribe, and share on this video and all the videos that you see there. Click the bell notifications. You'll get updates on the videos we do each and every day here at Summit Automotive. In fact, in a second, we'll see a link to subscribe to our YouTube channel on the upper left. A link to more RAV4 videos like this one, the upper right, a link to this vehicle on our website on the lower left. And a link to one of our latest YouTube videos on the lower right, click those, check us out. And we're super excited to help you with this Ultra Clean 2020 Toyota RAV4 XLE in midnight black metallic. Thanks again for checking out the video. Remember to like, subscribe, and share.


The mountain queen, a journey to the great king, mountain girl from long ago, picked glories, by the way, to weave a flower princess crown and gently rule the day. Each day, she'd rule with tender grace upon the mountainside imagining the mountain king, and she would be his bride. Now, mountains live forever, but time was not as fair to his beautiful young maiden who wore flowers in her hair. She still would come to see him, climbing slower than before, and he feared the day he might not see his fair queen anymore. Her legs were weak and feeble, but every day she'd gaze and dream of running up to him as in her younger days, one day with all the strength she had and every step in pain. She climbed her lonely mountain to see him once again. She promised him that she'd return, though not to run and play, but she would need a place to rest where she could always stay. Now she sleeps in silent peace with glories up above, and he knows that he will always hold his dear and precious love. Yet, far beyond this temporal place of earth and sea and wind, the king of all creation crowns his princess once again.


So now, here's a little bit of a review of coordinates, latitude and longitude. And I'm primarily using this for my online lab students just to give them a quick overview to make sure they're on the right track before they start their lab. So we start with the definitions. And I find that the most common problem here is students flipping these two definitions. So latitude is the one that's north or south of the equator, and longitude is east or west of the prime meridian. Those are the definition in words. But what we really want to see is those on the globe in terms of a picture. So here's an example. If I look at the globe, and I mark my equator here on the globe, then each one of the latitude lines, which is also called a parallel, is parallel to the equator. And they mark up, are you this far north or this far north? Or are you this far south or this far south, showing you where you are? So these parallel lines of latitude show you how far north or south you are of the equator. And the equator would then be at zero. For longitude, the lines are called meridians. And they go from one pole all the way down to the other pole. The prime meridian is our zero spot. It's a little bit arbitrary, but it's the one that goes through Greenwich, England. And then we measure how far east or west we are of that prime meridian. So these longitude lines go up and down from the north pole to the south pole. But they're measuring how far east or west you are. Now if you look at this on a map, you might see it a couple of different ways, depending on the projection of the map. So again, the latitude lines are going to be these horizontal lines that show how far north or south you are. Whereas the longitude lines, here's the zero line going through England, which is our prime meridian. And then these would be our other meridian showing how far east or west you are. Be aware that when we try to take a round globe and flatten it out, we end up with some issues. So some map projections try to arrange or correct for this, and the longitude lines will actually curve as if this was wrapping around a globe. So on some of the maps, you want your longitude lines to follow the curve versus the straight up and down. And remember, all of this is based on what's happening on a globe, so the curve makes sense for the longitude lines. Now when we talk about hemispheres, the northern hemisphere is everything which is north of the equator, and the southern hemisphere is everything that's south of the equator. So it only deals with latitude. You could be at any longitude and still be in the northern hemisphere. So this blue section shows the northern hemisphere, and down here, the blue section shows the southern hemisphere. In a similar way, the eastern and western hemispheres are dealing with longitude. So everything that's east of the prime meridian or everything that's west of the prime meridian. And that's how we can break it down into hemispheres using either the latitude or the longitude. Now when you have your actual coordinates of a location, latitudes have to have a number and north or south. Longitudes must have a number and east or west. So for example, 33 north 81 west is in South Carolina, and the north is the latitude, and the west is the longitude. And the reason you have to list the north or south or the east or west is because the same numbers, 33 north and 81 east, is in China, a very different place on the globe. So if you didn't specify it, and you just said 33 81, you have no idea where that is in the world. You don't even know whether they put latitude first or longitude first, because they're just two numbers. It doesn't tell us where we are. So when you actually have to list the coordinates, do not forget the north or south if it's a latitude, and the east or west if it's a longitude. Without those extra pieces of information, your coordinates are not complete. So that's just a review of the coordinate system, latitude and longitude, again primarily for the use of my lab students who are going to be working on an online lab. If you have further questions about it, feel free to contact me.