From Hollywood, it's time now for Edmund O'Brien as Johnny dollars Thanks lieutenant, how's the driver? What about the loss is the amount been figured out yet pretty close almost $250,000 I don't suppose there's a chance but was any of it marked or listed by serial number very little of it You better come down The driver does regain consciousness. We may get something if he doesn't we'll be starting pretty much in the dark I guess both of us have done that before all right lieutenant honest, and I'll be right down Edmund O'Brien in another adventure of the man with the action-packed expense account America's fabulous freelance insurance investigator was truly Johnny dollar Expense account submitted by special investigator Johnny dollar to home office Columbia all risk insurance company Hartford, Connecticut. The following is an accounting of expenditures during my investigation of the month-end raid matter Expense account item one hundred and eight dollars and twenty five cents AFM incidentals between Hartford and Kansas City, Missouri Where I arrived some seven hours after the company had advised me of the loss sustained by armed robbery By the and over chain of department stores The first details I received was sketchy at the finish of a four-day month-end sale The armored truck that had picked up the receipts from three branch stores had been robbed One guard had been killed at the scene the driver Carl Biller was dying at 11 30 that night when I met Lieutenant Arneson in the hospital corridor I'm afraid I talked you into a way to sit down here Just saw the doc again and giving Bill a lesson now to live now His wife just went into the room never came back at all. No, I've been with him most of the time and had a man there And I wasn't what did you expect him to give you lieutenant? Sure according to witnesses he and the guard was shot down by one of the men in cold blood Not because they resisted the killers why to eliminate them maybe why because the victims knew the killer maybe in spite of the masks they were wearing That's what I hope you tell me that's a point How are these witnesses any good good as most the picture seems to have been two cars both sedan One of them is in the passenger loading zone when the armored truck arrived and parked in front of it These men you went and where then they sure did they knew the truck had picked up the receipts at the end of the stores across the In Kansas City, Kansas and independence and the one car was waiting for them at the store here The other car double parked the money came out the men were shot down And the truck was empty before anybody turned in an alarm how about license numbers both the rest of them call it Didn't work any way you want a dollar. I won't get me a road thanks lieutenant We're both aiming for the same thing and I'm going to have my hands full Robbery detail tells me they're informers have hinted that the gang has been forming here in town for the last month or two I guess they were right. We're pulling in everybody. We can't maybe we can get some talk out of some of them It'll be a slow process, but that's the way we work. I'll be in my up. Oh, yes, Cole Is he gone? There was nothing they could do Yeah, let's finish this that this is mr. Dollar Sergeant Cole. All right, Sergeant Cole dollars investigating for the insurance company Yeah, but they're hurting now. I've seen them in better moods Were you planning on talking to the widow tonight lieutenant follow up the possibility that he knew the killers What kind of condition is she in? Hard to tell she seemed to be standing up. All right I just as soon leave it to you tonight dollar Cole and I am gonna get back to headquarters and see what we've pulled in sure lieutenant anything you say A short time later a white-sheeted figure was rolled out of the bill a room Followed in a couple of minutes by mrs. Biller a plain lumpy woman in her 40s in silence She followed me into an empty waiting room a few yards down the corridor I want to go home. I've been here all day, and I'm tired. I can certainly understand that mrs. Biller, and I won't keep you long This may seem like a strange question under the circumstances, but Do you think there could have been anything personal connected with your husband's name personal? We're looking for a valid reason for mr. Biller and the other men being shot down the way they were what are you talking about I? Wouldn't he get shot didn't surprise me It was always with a lot of money, and I told him he'd get shot someday There was no apparent reason mrs. Biller. They weren't given time to try to protect the money. They didn't draw their guns Private guards work under orders to surrender as a rule, but they weren't given a chance They were met on the sidewalk and killed without a word. I haven't been thinking about anything like that all day long You've been wondering what would happen if he died Now he has and here I am with the house still not paid for in no money. I just have to face it Dead nuts all those to it you Want to help us find the man who killed him if if you could wouldn't you how could I help you do that? He and the other man could have been killed because they knew the man who killed him How could anything like that be? Why should Carl know anybody like that? We don't know that he did we only wonder and I read the papers How could he know anybody when they were all wearing masks? That could mean that he knew them very well well enough to recognize them in spite of the masks Don't you see what I mean mrs. Biller? I Can't think you couldn't expect me to think after a day life. This has been I Don't know what to say. I'm all mixed up now. I understand mrs. Biller. I won't bother you anymore tonight What we want to know is if somebody who knew your husband and knew quite a lot about his job Could have been responsible for his death and the robbery We'll talk to you about it again Maybe tomorrow Lieutenant Arneson thought enough of the interview on the widow's reaction to assign a couple of men to keep her covered The police spent most of that night pulling in known and suspected criminals and grilling them without any definite success The next morning I was in the new tenant's office while he was waiting for one of his informers to be brought in Nothing under missing cars yet. I love it. I'm dead certain they haven't got out of town He had it sewed up in a hurry. I put another man on a billar angle to looking into his habits and friends But staying away from his wife We'll save her for you. Thanks a line. I thought you'd like her Here's the count lieutenant. Yeah, come on in a well This is a male or dog sometimes called a count sit down there You and I have known one another for a long time, haven't we? I owe the lieutenant a deep debt of gratitude Yeah, get along Evil this man's working for the insurance company that covered the missing money You can trust if you say so what else what's going on in town email? What does the crowd say about this heist they don't say very little they don't like this These are foreigners who do this from where Chicago the crowd don't like this doesn't look like a fine job to me They knew just where that armored truck would be and we're waiting for it How it outside is get information like that. Who are these foreigners and where are they where they are? I don't know who I hear only some names that are nothing one is pinkie one other is Ross First name alas only Ross other is shorty other is the meek Who their other names are nobody knows? He's not much lieutenant, but I am only a man Anything more Johnny? Yeah You know if they're still here in Kansas City How do I know that so I from the crowd and the only one who knows where they are then I am shot, too The lieutenants seem to be fairly sure that the man and the money was still in town All the escape routes have been covered by police armed with Composite descriptions of more than 30 witnesses to the shooting the information given us by the informer was almost worthless But the first names and aliases were wired to Chicago for a search and the officer working on the bill angle came up with a development later that Same afternoon So I was armed with at least something definite when I went out to see the widow doing better today Some ways I do some ways. I don't This is bill. I Learned some things this afternoon that I hope you've been thinking about what your husband of this woman named Betty Claire I was going to tell you What do you know about it? She's married to a man who just got out of prison. I was going to tell you I Knew she'd get him into trouble sooner or later. I did all I could to get him away from her Even wrote a letter to the bonding company that she was nobody to be hanging around somebody with Carl's work He saw her after her husband was parole not so much. I guess but the husband was away sometimes. I don't know Yes, Carl went to see her some then you must have thought of her when I talked to your last night I did there's no use lying. Why didn't you mention it? I don't know Maybe I was ashamed of having a husband some other woman could keep a hold on until she got him killed And you think their association was one where he would have told her details about his job Yes, now you'll admit that you think she had something to do with the robbery. Yes Because Carl didn't come home night before last I don't know where he was But he came here in the morning to change into his uniform than he left That was the morning. He was killed. Did you ask him where he'd been? No, I got over doing that quite a while ago As she been arrested not yet. Tenon honest and is waiting for me We wanted to get what you had to say before we talked to her Do you have anything more? No Except I hope she gets her as much as she's made me get it. I think that's all there, Mr Bill, I'm sorry you didn't mention this last night. I hope we aren't too late now I guess we're safe he will return you to the second act of yours truly Johnny daughter in just a moment There's lots of good folding money and an hour of merriment and music on hand again tonight when CBS presents sing it again The phantom voice brings an extra tingle of excitement and pays off handsomely when Jan Murray uses that coast-to-coast phone Here sing it again on CBS tonight Now with our star Edmund O'Brien, we return you to the second act of yours truly Johnny dollar They have been strangled obviously by a pair of hands The apartment showed signs of a struggle but further search revealed only a newspaper whose date and time Seem to indicate that she'd been killed after Carl Villa had died There wasn't a lead as to the possible whereabouts of her husband Arnold Claire But the search for him was speeded up at five a report from a section of Kansas City called East Bottom did give us a lead The body of a man was found in a garage He'd been shot to death and in his pocket was a receipt for an insured parcel post package a follow-up on the receiver's address Showed the package to contain $15,000 in cash Later the informer email order followed the lieutenant and me in to view the body Okay, Charlie. You know this man email. How could I be sure? He's one of the crowd. I know who he is. You know His name is not what you know it is. Yes. I know Oh no the record of narcotics possession suspicion of burglary 60 days last year in vacancy and carrying a concealed weapon Yes, I'll know what the lieutenant tells me he's not from Chicago. I know that he's a local boy Yes, you still say the antler of a job was pulled by Chicago men. This is what I think what the talk is I also told dollar that I never could really trust you a There was always a chance somebody might buy you into bringing me false information Oh, no, couldn't somebody who just made a $200,000 haul by you into it a move. Oh, no No, he's not going to do you any good if I find out you aren't leveling with me I got about four charges. I can bring against you. They send you up for quite a while I owe you deep gratitude. I tried to find out more. So you let me go now I'll give you the rest of the evening up to 10 30 a month one thing you don't have to find out nor with hair Send 15 grand out of the city by mail. There's only one reason he do that. It was mixed up for the end of a job I'll get going. I'll pick you up later The two additional killings possibly linked to the robbery said Kansas City is underworld and police force spinning Every officer in town was put on duty until further notice by eight the tanks were filled with woodlands While the streets and hangouts were strangely empty and silent At nine o'clock it seemed that things started to break a known associate of Arnold Clare was picked up and brought to the lieutenant's office Sure, sure. I know Arnold. I was in prison with him I met his wife the other night, but I don't know anything about the handover job Well, where you're the morning was pulled. Listen, I got alibis to prove I wasn't mixed up in nothing. What about Arnold Clare as far as I know. He was going straight That's what he told me anyway. We've got Clare linked up pretty close We know his wife was running around with the driver of that armored truck That would give Clare access to the information he'd need. Well, I can't help what his wife was up But we told me he was going straight said he was looking for a job When did say that last time I saw him the other night when I met his wife Tuesday it was Tuesday night. Yeah, robbery came off Wednesday morning and you were with Clare and his wife Tuesday night That's right. I tell you I don't think he had nothing to do with it. How late were you with him? Oh must have been 1 30 2 in the morning and Betty Clare was there all the time. That's right Doesn't jive with Mrs. Biller story lieutenant. Look, I'm telling the truth. I got no reason to lie How about proof? Is anyone else there? Yeah? Yeah, somebody else was there We ordered some liquor sometime around midnight the boy from the liquor store brought it up. I've Forgot the name of the place, but I can show you Mrs. Biller said her husband was with Betty Clare the night before the robbery That ain't true. Nobody was with her, but Arnold and me I'll take you to that liquor store and she was killed yesterday the day after Biller died. What why? Who was killed? Are you sure Biller wasn't with you and Betty Clare and her husband? You're telling me Betty Clare is dead You know she is strangled now. Tell us why wait a minute wait a minute. I didn't know anything about it I swear I didn't I'll tell you what Arnold is to prove I didn't know what kind of proof is that I didn't know I swear I didn't he didn't tell me he said there was too much heat on from the handover job And he didn't have an alibi for the whole morning. He said he wanted to stay out of sight for a while sure make himself look innocent I suppose I don't care what you think that's what he told me and that's all But if his wife has been killed, I don't want to have nothing more to do with him That's a real double cross to get me mixed up in anything like that. I'm through with him Where is he? There's a shack out by the Hedger town near the river. I've been taking food to him.  You're the first real live hunk of progress. We've had we want to hang on to you Come on.  He's dead. Yeah, the report just came in That's too bad. He's a good honest story and I'm going to miss him. It's a better start. Don't you think the town is really hot? I can't remember it ever being this hot We checked stone story at the liquor store the delivery boy finally remembered and agreed that only stone had been with the Clare's in the apartment tonight before the robbery 20 minutes later with headlights out our car pulled up on a dirt road The shack stone pointed out the screen by a stand of willows on the riverbank One small window showed some light from inside Wait, wait a minute. I ain't going in there. You can't make me come on. Come on. Come on. You'll kill me. No, he won't stone Let's go.  I'll take it. Hey, we are clear Stalled in the chair Then an honest and homicide stalled you saw me out. I'm trying to lie to me I'll you lied to me you didn't tell me about your wife and you was getting me mixed up in a killing Well, I don't set with me and I called you my for the back Checking for weapons Jenny sure Relax clay.  I Will make a play. There's a 38 my left coat pocket You can sit down Why do you want to start clan? I I guess it don't make much difference doesn't why'd you kill your wife? What makes you so sure? I I killed her because I was trying to go straight this time And she got mixed up in this handover job I'd known about it before I'd stopped it for sure, but but I didn't find out until after it happened How did you find out one of the guys that got killed the driver bill his wife got me on the phone the night he died She told me about About Betty and her husband you didn't know about it. No, I didn't know this dame told me about it all the years I was in prison and after I got out every chance they had not the only reason you had I told you I was trying to go straight And I found out Betty is working this bill into setting up a job with She was doing it to get rid of me again She knew the board would take my parole away no matter what I said Mrs. Biller told you all this her husband talked about it Before he died.  I am sure but I couldn't help it. I went crazy Betty wasn't at home when I found out I I guess I drank a lot and thought about it When she came home, I just grabbed I couldn't help it. I knew I was killing I couldn't stop You know something I Don't care that's the spirit. What about the handover job? How much do you know about that? I I know one guy that was in on it and I'll finger them for you. I'll finger them I'll see some of them take the same ship. I'm taking From the break stone gave us the case snowboard The man Clare took us to let us to another and he to another Dwent that way until 430 and all that remained with the men from Chicago. We'd heard of earlier They were holed up in a house together and one of them Ross Degnan had been the killer during the job He'd killed for no reason except that he'd been under the influence of narcotics Don was just beginning to break when the stakeout was drawn around the house Fasten I wanted one of the men who got here before we did says he heard a phone ringing in the house. They've been tipped I'm probably such a call I think so you covering me with a Thompson from the driveway near the porch there. Yeah, you aren't forgetting those sort of shotguns Are you not going to get within range at me? Try to call them off the street Wait car starting. Where is it? The garage they've got into the garage the garage you may not have back cover the garage Watch it here they come We'll use it get the driver, but we saw the end of the trouble there on the street What the Chicago men had with them and stolen money brought the recovery up to within $2,000 of the original amount Expense count item two hundred and eighty dollars miscellaneous item three same as item one transportation back to Hartford Expense account total three hundred ninety six dollars and fifty cents remarks. I Talked to Mrs. Biller before I left Hoping to get some kind of revenge against the woman who'd stolen her husband She told Arnold Clare that Betty had set up the robbery, but she got her revenge Murder and the company owes her a deep debt of gratitude because when that broke the whole thing broke It was truly Johnny dollar Truly Johnny dollar stars Edmund O'Brien in the title role and has written by Gil Dodd with music by Wilbur Hatch Edmund O'Brien's latest picture is a Paramount Pictures production the redhead and the cowboy Featured in tonight's cast were Herb Butterfield Joe Deval, Virginia Greg Edgar Barrier Sydney Miller and Peter Leeds Yours truly Johnny dollar is produced and directed by Jaime del Valle This is Dick cutting inviting you to join us next week at this time when Edmund O'Brien returns as yours truly Johnny dollar There's one fire in an American home every 20 seconds that fires kill 11,000 people every year staggering isn't it 90% of fires in the home start through carelessness Be careful with matches and keep them out of the reach of children and if you're a careless smoker Don't smoke in bed or discard lighted cigarettes thoughtlessly Don't gamble with fire The odds are against you Stay tuned now for five minutes of the latest news This is CBS where our Miss Brooks holds classes every Sunday night the Columbia broadcasting system


Thanks for sticking around. My name is Jean-Yanise. I'm one of the co-founders at Arjen. And today, actually, I will not be speaking about Arjen, I will be speaking about Upper, which is an open source privacy mincer that we've developed internally. Actually, most of this work was done by only the event of being allowed from our team. This is going to be annoying. I'm going to plug my batteries in. So that should be better. So I was saying I will not be speaking about Arjen, but about Upper, which is what was mostly done by Olivier van den Wigner from our team. So the credit should go to him. And if you have a pretty deep technical question, I will also ask them to him on Twitter. So I just said I will not be speaking about Arjen, but I think there is some value in briefly describing what Arjen is, because it gives some context on why we started working on the privacy mixer. So Arjen is a smart contract based wallet with a lot of cool features. We have seedless recovery. You can block further than transaction. You can freeze your account. There's no abstraction of gas or transaction fees, every user has an ES and so on. So basically what we try to do is abstract most of the complexity of the blockchain and enable an experience similar to what you get on the best mobile banking application today, but in a fully non-custodial way. And the vision for that is that we want to enable actually people which are outside of Crypto Bobo to access the blockchain. And so if you start to build a new financial system for people that actually are not really tech savvy, they have some kind of expectation of what that system or the features that that system should provide. For example, people assume that if you transact, that doesn't give the person you transacted with access to your entire history. For example, I mean in the future I'm just making a transaction to my insurer. I may not be okay for my insurer to know that I just visited an oncologist two weeks ago. This kind of information should not be disclosed and should be private. And of course an Ethereum, which is a public ledger with full transparency, you don't need these properties. There's also an economical argument for privacy, is the fact that you want your token to be fungible. If I send you one Eater, you want that Eater to be worth one Eater. Now if you know where that Eater comes from, actually you may believe that it has this value because it can be tainted. For example, it comes from an exchange being hacked. That token may be worth less than actually one Eater. So these properties are very important. So if you want to be inspirational, you can say that privacy is necessary for an open society in the electronic age. If you're a bit more pragmatic, we actually allowed users saying that they were feeling uncomfortable by linking a hardware wallet on which they had a lot of funds with their urgent buy. And actually this second quote is really the use case we try to solve. So we really asked our question, can we actually address this very simple use case? A user wants to fund his urgent wallet, which has no fund, and send it from hardware wallet. And can we do that? Search that. The two addresses are not linked. The process is fully non-custodial. It is mobile friendly, and actually this point has driven a lot of choices that we've made to design Hopper. And of course it has to be economically viable in terms of gas. If you transfer one Eater, but you pay 0.5 Eater in gas to make that transaction happen, this is not practical. Fortunately, there are solutions to address that use case. And as you probably all know, ZK Snarex can be quite useful for that. We didn't start from scratch, so we should also give some credit to the team of Barry Whiteland and WJ. That was on the panel with me earlier. They've done a great work on Snark Miximus and now SEMA4. And so basically we try to extend what they had done, build on top of what they had done, but really customize it and make it practical for our target use case. So all those Hopper or Miximus works, it's that basically if I want to send a coin to someone, I will need a secret coin, which is a leaf in number 3. And the person that wants to withdraw that coin needs to prove that it knows the secret behind one of the coins and that this coin hasn't been spent yet. So the principle is quite simple. In practice, all those Hopper work, because we do have an iOS application that you guys should try, which is in alpha now, but I think it's a good way to see what it does. So basically the client using the Hopper application will generate a leaf. So we just do a SHA-256 of a secret and the destination address.  Of course, other people will do the same and each transfer is of identical value. As you will see, this is critical. And that results basically in a sea of identical transfer. Of course, the more you wait, the more people will deposit either on the mixer contract and the more your anonymity set increases. I put an asterisk because it is not as simple as that, but it provides the intuition of how we get anonymity. Finally, after a certain time, the person who wants to withdraw the coin, again using the Hopper app, can tell the mixer to send the phone to the destination and you do that by sending a proof. The mixer contract will verify the proof and if the proof is correct, it will send the phone to the destination address. For example, that might need that secret to be transferred and hurried and you receive your 1 liter on your object wallet. The flow and the user experience is actually quite simple. We are always in work-in-practice, so I will not go deep into the ZKSNR framework for mixers, but basically you want to prove that you know a secret behind a leaf in America 3, where the leaf is the SHA-256 of the secret in the destination address, and you want to prove that that coin hasn't been spent yet. So actually you can translate that into mathematical equations and that will give you a circuit. In your case, these are the set of equations that we want to solve. This is the secret inputs that we want to prove we know without revealing them. And of course, there is some public inputs. So using this, you can actually build your circuit and have your verifier, your prover, using libraries such as this one. In terms of smart contracts, this smart contract is quite simple. As far as in terms of the API, we have two main methods, a commit, where you deposit your funds and you attach your leaf as data, and then a withdrawal function where you specify the public input that I just showed, the destination, a nullifier, which proves that there is no double spend, and then the proof that you have constructed using the ZKSNR framework. So that's kind of the general framework. As I mentioned, we are similar to other mixers, but we have different choices that you make for your implementation. So in the case of Uber, we use MIMC for the ashing function of the miracle tree. MIMC stands for minimal multiplicative complexity. The intuition for that is that in the ZKSNR framework, you have your equation, you translate that into a circuit with addition and multiplication gates, and actually the number of constraints that you will have depends on the multiplication gate that you have. So if you use ashing function multiplicative complexities, that means less constraint. That means generating the proof will be easier off-chain and that means that it is more mobile friendly. So we've made that choice so that you could actually generate the proof on the mobile within five or six seconds. Of course, there's a few drawbacks of using MIMCs. As always in engineering, it's a question of compromises. If you use MIMCs, they are more expensive for the EVM because there's no pre-compile and MIMCs, as you will see, there is an idea for that. But as of for now, doing MIMCs on-chain is quite expensive. So actually when you deposit a leaf, you need to update your miracle tree and that requires a lot of gas. And also MIMCs have been less studied. And if you are at IAAS presentation this morning, they highlighted that the Ethereum Foundation is studying research on MIMCs for specifically that reason. So to mitigate the risk associated with MIMCs, we are actually using SHA-256 for the leaf of the tree. We're not going to the cryptography behind it, but the intuition is that even if MIMC turns out to be non-pre-image resistant, you will still have privacy assuming that MIMC of one half of the input is pre-image resistant. The problem is that using SHA-256 means more secret constraints, and so again we increase the generation of the proof. So as I illustrated in our use case we want people being able to transfer one leaf from hardware wallet to a large end wallet that has not been funded yet. So the question is how does the person rejoin the money will pay? There's no leaf, it cannot pay for the gas. And so the idea is to use relayers. And so in our case, we have developed our own relayer. There's work being done by the semaphore team on the gas network station to actually use a network of relayers. And the idea is that the relayer will basically make that withdrawal transaction on your behalf, and it will be repaid the gas that it used by taking a small cut on the deposit. As we discussed on the panel, there is some there's some risk of using relayers because of course you're using a centralized you may not be centralized but using a system with an API, so you're making an API code that means that people can use your IP address to kind of reduce your anonymity. So there's a lot of consideration to take into that and one possible solution is to have a relayer market with built-in torque routing in. Another important question with Mixer is when to withdraw your funds. Because of course if you deposit your funds then you withdraw them immediately then it completely breaks the anonymity. If you deposit your funds but you always withdraw them after 24 hours, it's the same. People naturally tend to have patterns and so this is something that needs to be mitigated by actually the UX of building a Mixer or do you incentivize users to actually behave correctly or in a smart way. The problem is that, yeah, whatever anonymity you use, for example in Hopper we just illustrate the number of other leaves that have been deposited since we deposited so that can be represented anonymity set but again this is not a perfect metric because say my anonymity set is 17 maybe 16 other deposits they come from the same person which is actually trying to target me. So it's really tricky to find proper privacy metrics and so in the next version of Hopper the idea is to basically only enable you to withdraw your funds after a certain time so that all users depositing within one day will be incentivized to withdraw more or less at the same time and so again you kind of increase the anonymity. So I mentioned that we only enable transfer of one leaf again this makes sense if we let people deposit 0.77 Eater for example and then someone withdraws 0.77 there's a good probability that these two people are actually connected and again you've recreated that link that we're trying to break so the idea is to fix the amount that people can deposit so they become indistinguishable. Now the one improvement that we can do because of course if there's only deposit of one leaf it's quite limited so the idea is that we could make a contract for one leaf, a contract for ten leaf and a contract for a hundred leaf but the problem is that you split your anonymity set and again this is not a good idea. There are a solution and this is something that we work on in the future or that you want people to work on is the possibility to use jump speed circuit so basically the idea is that you always deposit a multiple of one leaf and then when you want to withdraw you can actually combine two leaves into one and so you can for example withdraw one then or one hundred without breaking the anonymity. Another limitation of Hopper is that there's only around 32,000 leaf per contract and the reason is that you have numerical three and the more depth you add to your numerical three the more expensive it is in terms of gas and since you wanted to keep this under a million for the deposit and the withdraws it's kind of limiting the number level that you can add in your numerical three and so the number at the level of leaf that you can deposit so we have fixed that at 15 which gives the gas around a million. The problem is that once you fill up your three you need to deploy a new contract. So I've talked about some of the limitations of Hopper fortunately there's a lot of areas for improvement one is around optimization so you could patch the public input into one which would reduce the number of more strain. You can optimize the contract for the moment the contract is in clean solidity there's some step that could be written in assembly that would reduce the consumption by 15 to 20% and again that enables you to increase the depth of your three and so the possible deposit that can be on a single contract and there is work on the new EIP 1108 Radia SD which is a pre-compiled from MC so that would greatly reduce the gas of computing MCs that means updating the Merkle 3 would be much cheaper so again we can use a much bigger Merkle 3 Another functional improvement that is part of the next iteration for Hopper is to store a buffer of the recent Merkle rules because now when you want to create your proof you need to have a Merkle path to the EIP that you want the problem is that by the time you compute your proof that may take 5 to 6 seconds and then you submit your transaction to the blockchain again it may take 15 30 or 1 minute to be mined it is possible that someone deposits a new leaf in between which will update your three and then suddenly a Merkle path is no longer valid so by keeping a mystery of 3, 4, 5 Merkle routes actually you can improve the number of withdrawals that will succeed as I mentioned we can allow custom withdrawals using John's clip and then we can work on a linear market so that's it that was kind of brief but I hope you guys enjoy if you are interested by Hopper you can check us on Github the project is fully open source and the idea for us is to build a tool for the community so this is not to be an urgent project so feel free to contribute if you have questions you can ping us on Twitter or Telegram and if you are interested by Arjun you can download a wallet right now using the link that is there and that's it for me thank you do you have any questions? how much gas does it cost? so we limited it to a million so a million to deposit and around a million to improve can you elaborate more on what is this? yes, expertly the idea is we need to make a proof that we combine two Merkle leaves so say I have a Merkle leaf which has one eater another one that has one eater I do a Jones leaf and suddenly I have one leaf which contains two eater and one that contains none so if I withdraw the one with two eater suddenly I can actually withdraw different amounts yes, this way but again you can combine the Jones leaf with the withdrawal with the specificity we kind of see like that but we need the ideas to enable custom amounts because we still need to know the secret behind discount so it's not like you can transfer with someone else unless you transfer them the secret but the idea is more to be able to join the amounts thank you


Fidelity announces a youth investment account for teenagers. I think it's something like that. Don't quote me on that. But a youth investment account for teenagers. Ladies and gentlemen, today we're going to be talking about the youth investment account for Fidelity. But before we get into that, this youth investment account, is it going to be good for kids or teenagers?  I'm going to give you my personal take on it. And also I want to go through the history of how did we get here? So the first thing we got to look at before we got to this youth investment account, we must first look at what has changed in the world over the recent years. What has changed over the world in the recent years is a couple of things. One is accessibility. Accessibility to the market has increased dramatically over the last decade. But not even a decade, the last 20 to 30 years accessibility to the market has grown dramatically. So people say, Prince, what do you mean by accessibility? Let's go back all the way back to 1990. If you weren't to buy a stock, what did you do? If most people didn't have internet at their house, so people didn't have access to the market, like they used to have.  You had to go downtown, talk to somebody in a fancy suit, call somebody in a fancy suit, pay broker fees or pretty high back then because of the friction that it costs in order to get something. What I mean in order to get something was for prime example, if I was your broker and you called me and said, buy one share of Apple, I had to have access to the floor. I had to have a terminal, Bloomberg terminal, to get access to the floor to say buy one share, which cost me a lot of money in return. I had to pay, I had to charge my customers, right? Nowadays we have this fancy thing called the internet. More importantly, we have this fancy thing called laptops. And even more importantly than that, we have these fancy things called cell phones. That's right, ladies and gentlemen, kids are sitting at home, parents are sitting at home. A lot of you guys and girls are probably watching this, catching it live or the playback, listening to this via a phone or a tablet. So now we have people that can go into a plethora of online brokers and they could go in and buy their own stock immediately, for a little to nothing. Now let's get before we say little to nothing. What that started to do, once we had the online presence that hit back in 87, some people contribute the 1987 crash to a lot of computers being introduced into the market, but what happened was when we had these online computers, what started to happen was more people started to use it over and over and over. You get to myself saying it started to happen. But more people started using over and over and over and over. So people, so what that did to broker fees, that lowered them to lower prices. At one time, when I very, very first started trading, a $12 broker fee was a great price. I remember when E-Trade was like the lowest fee in town, it was $9.99. And then guess what, guess what happened? So you had lower broker fees, you had accessibility increase, meaning accessibility. People no longer needed the traditional broker downtown like our grandparents did, our great grandparents. Now people can just pick up their handy dandy phone, their tablet, their laptop and say, hey, you know what, I have access to the market. On top of that, what happened was since the internet came along, it made a lot of things more affordable. For prime example, one of the most and major things that made more affordable was trading online. Trading online dropped to a fee of nine, about 20 years ago, 10, 20 years ago, it was about $9.99. So now that you see in prices drop down to $9.99, that was an awesome price. And then the retail investors started to compete. Your Charles Swabs, your TD Ameritrade, things like that, they started to compete to $8.99. And once the fees started to go down, somebody came along. I think they got all the way down to about $4.99. I think the lowest price in town probably was maybe Charles Swab. When you got the lowest price in town, guess what happened? It was this company that came out of the blue, stole the heart of all the young investors with this gamified way of investing, no fees. I wish I had a drum roll, I should roll my drum roll. Drum roll, it was a company called Robinhood. Robinhood changed the game when they came in and announced no trade fees on their app. Immediately, everybody said, hey, you know, no trading fees. Wow, how are they doing this? I can trade stocks and ETFs and mutual funds. When they announced that they gave them a superb competitive advantage and they catered to young investors. When I say catered to young investors, one thing they did beautifully was they launched their own app and inside the app, they made it almost like a game when you buy your stock. You walk in, it was no legal jargon, it was very easy to set up. All you had to do was just, it's a big old green button that says buy, it's a big red button that says sell. Pretty simple. Then, you know, it has a chart of what's going up, it'll tell you what's hot, what's not hot, all the great stuff like that. Stole the heart of a lot of our young generational investors. Now, what went wrong? What happened with that? Now, also just keep in mind, what happened with this at the same time, if you watch the documentary right now on Netflix called Money Explained, very good documentary season one, episode one, very awesome documentary, by the way. And what it said was, what it listed out was, we have a massive level of influencers that have changed for the cheap. So what they mean by that, let's say people like myself go on YouTube, Facebook, Instagram, broadcast on your local radio, your local television, podcasts, iTunes, or whatever, have accessibility to people across the globe that we never had. See, before the social media became a thing, you had social media influencers, you had people, you know, those little cheesy daytime, not daytime, but midnight commercials that you would see that come on 10 o'clock at night and say, hey, buy this doc today and do this today, and blah, blah, blah, you wanna get rich tonight, you wanna get rich tomorrow, look at all the people I made rich. Those little get rich schemes, they were kinda came on at night, someone came on in the mail, someone even called your house, all those types of ways, but those things were very expensive when you had cable TV. Cable TV, in order to continuously run those ads for weeks and months at a time, that cost thousands and thousands, not millions of dollars to have that ad space. Now it's became so cheap that anybody can create a Facebook page, an Instagram page, a YouTube channel, a podcast, anybody, market is opening up and exploding and it's opened up for a great thing, so a lot of people learn some things, but now it opened up the crooks and the people who are not so good to people who have very bad intentions, very bad intentions, it has opened the door to them, right? So now you have people who have very bad intentions who will usually be on midnight at 12 o'clock at night running some crazy ad about get rich today, get rich tomorrow, look how I got rich, all my friends rich, don't miss out on this. Things that has been going back in time all the way back in the day when people used to knock and go door to door. Now it's created what we call social media influencers. Now you have influencers online today telling everybody, hey, buy this stock, sell this stock. Your kids at home with their phone or teenagers at home with their phone and they're following things like that, no fundamental data, no technical data, most cases sometimes, hey, look guys, I made a thousand percent off of this stock. Hey, look at me, I made a million dollars.  So for prime example, everybody is seeing people on social media and they're just running to it. For prime example, we had the birth of what's called meme stocks. What are meme stocks? Meme stocks are essentially stocks that pretty much went viral on our meme. So for prime example, one meme cryptocurrency was, I think it was called SHIB, but then you had Dogecoin, all these different things. Accessibility has gone crazy, influences has gone crazy. So now more than ever, the good thing is, more people who usually wouldn't have the accessibility to invest are now interested in investing. Another thing that I kind of touched on, affordability, now they have something called fractional shares.  For prime example, Amazon is trading over $3,000 as of today of this recording. Meaning maybe some young people who don't have $3,000, they will not buy Amazon. But guess what fractional shares do? Fractional shares says, hey, if you have $200, I'll let you buy 0.0001% of Amazon. What this essentially does is it's taking a big stock like your Google, your Amazon and things like that and it's companies that people would love to get into and it's slicing them down into affordable slices.  So now you can own a fraction of Amazon. This in return, ladies and gentlemen, made investing more affordable. Back in the day, 10, 20 years ago, when we had trading fees, if you wanted to go buy a penny stock, it would cost you $10 to go buy a penny stock, $10 to sell the penny stock. Now it's a penny stock really affordable. And then you know, right now, still on a lot of trading platforms, they still charge the fees. But guess what? Today, now anybody can pick up a, somebody's listening right now, by the time we get through with this episode, a person can start them an account online with an online broker that's choice, put money into their account and be on to the investing life of building their own first portfolio. This is very great because it's opened up the accessibility and affordability to a group of people who never would have had the opportunity. Now let's look at the downside. Fundamental analysis has gone out the window. When you look at companies like, you know, a lot of the apps they don't even offer you ways to compare to the S&P 500, it doesn't tell you what's an S&P 500. You can do little to no technical or analytical fundamental data with just those platforms. It's just almost gamified or gambling, the way people do things. Now I want to segue for a second. When I talked about gaming and gamifying investing, I look at the world of investing now and it's my personal belief. Now this is not backed up by any factual data. My personal belief is that you look at the world of like crypto currencies and a lot of penny stocks, they have turned into the new way of lottery, just like the new generation of lottery tickets. Think about it, when was the last time you probably seen or heard of? I think the last report that I read, most lottery players are at the age of 60, 65, right? 60 to 65 is how old most lottery players are. Look at the people who are 18 or 19 years old. 18 or 19 years old, what do these people do? Do they go, are they the ones that go to the local 7-Eleven or gas station or whatever and buy a stretch off? Probably not. Are they the ones that go to the local gas station and buy, keep me thinking the name of it, it's called cash three, cash four. You know one of the tickets you're going in or they rip you off a couple of numbers. So when you look at that, ladies and gentlemen, that tells me that the young generation are not the ones who's really interested into the lottery, but that same young generation will do what? That same young generation will get online and they will buy a cryptocurrency they have never heard of. They do that in a heartbeat, no problem. Why would they do that? Why would they do that? Because nowadays the accessibility and what they're doing today, it makes sense. So for prime example, when you look at kids today, they are more interested in getting an app and buying a particular stock or a company. Now, we get all the way down to it today. With this type of way of thinking, with kids becoming interested in investing, accessibility, affordability, all going into the market at one time, this has created what we know today as a new market for young investors. Again, say that again, a new market for young investors. Young people now have the opportunity to invest more than they've ever had before. You have a bunch of young people who are being influenced, who they're being influenced because they have social media. They're watching all these means stocks. They're watching their friend who bought a bunch of Doge corning, got rich and all those stuff like that. They're interested in investing. You have companies like Robinhood, who has gamified and simplified and elementary-fied the way of investing, which is a good thing. But also almost too good of a thing. You know, almost makes it seem like it's a game more than actually investing for your future. Then on top of that, you have, you know, credibility, accessibility and affordability going on with the influence. This opened up a market of young people wanting to invest in things like that. This is where fidelity comes into play. Fidelity notices this.  It's almost like, to be honest with you, ladies and gentlemen, it's pretty much like a custodian account, but yeah, I don't really see the difference outside of it. It's more like a custodian account, but it's targeting towards teenagers. I haven't seen the cool thing about this teenage account, but hats off to fidelity for launching this and saying, hey, this is for teenagers. So for a prime example, I can get my son a credit card and a debit card through fidelity and give him an investment account with fidelity and I can watch all his trading activities. I can put money in his investment account and watch him trade his little heart away. You know, so I guess it's a good way to get kids into investing and watching their portfolio. And then when they turn 18, it's theirs. But you can get that same effect today off of a custodian account. When you look at a custodian account, you know, I think I got my son's custodian account when he was maybe three, four, five years old, something like that. Started my investment account, started putting some money in there, built him a little portfolio. When he turns 18, it's gonna be his. Of course, when he gets to 13, 14, 15, if he wants access to it and he wants to invest or whatever, I'm gonna allow him to do that. So with this new way of fidelity, what they're saying hats off to them, but I don't really understand how this children's account is different from what we already know as a current custodian account. But that's what they're doing. So if you are a parent and you have fidelity, this is a great way to say, hey, son, daughter, you wanna start investing, I will be the owner of the account, I can give you a credit card and you can start investing that way. So ladies and gentlemen, this is gonna conclude today's episode. We essentially went over why, how did we get to this point with fidelity and fidelity launching their new youth investment account for teenagers targeted from the ages of 13 and 17 to get them into the investing world at an even younger age than adults, then 18, 19, 20, then generation, what we on Z right now. So right now, that's a great way to do it. So anyway, that's the pros of it is that it gets your children into it early, they can invest into it, the cons into it.  As long as they have a social security number, you can open up an investment account for them and start at a young age. All right, so anyway, ladies and gentlemen, my name is Prince Dykes. I'm the Prince of Investment. I thank you guys and girls for tuning in today. Hopefully you got something out of this, seeing how did we get to this point. Don't forget to hit that like, subscribe, comment, and share button and tune in and don't forget to drop some comments. Tell us what you think of the episode, all right? And to the next video, podcast, cartoon or whatever else crazy you see me doing around the globe, my name is Prince Dykes. Peace, be safe, I'm out and thank you.


FNN. The Tiger financial news network update. Good morning everyone. Basel Chapman on this fourth day of October Tuesday. We're looking at the Dow in the Tiger Financial News Network 10am market update up 727 at 30,220. Very good move because it's over. Finally, it is over the Black 14 period exponential moving average. It's done that before when it had those four fantastic sessions back in early September where Dow went from 31,182 all the way to 32,000. Was that 500? Yeah, 504 on the 12th of September and that was it. Generated pattern as it failed the next day came smashing down, took out the support level and kept going down to 28,715 on Friday. Now this is really important because it's a chance that we're going to be making a V-shaped pattern. That's what you want to see. A V-shaped pattern was two strong candles, maybe three, but two definitely you want with a gap. If there's a third gap tomorrow, that's unbelievable. But in the meantime, the day is young. We're up 761. Let's look at the S&P. Also, the S&P is up, does up 2.9%. The S&P is up 2.8% and up 105 in the S&P at 37,83 up over the 14 period moving average of 37,54. That's near-term support now looking at the QQQ, the NDX100. Very strong move up today up 3.26% up 890 at 282.44. Also just above the 200 period moving average making the pink 277 level 9 period moving average, key support looking at the IWM. We'll talk about that in my show because I was asked about that in leg B. The others are in leg A. This is in leg B, means it's already started its move back at 163 a week ago. That's a good sign. We'll talk about it when I get back. It's up 5.80 at 175. Gold, is gold giving back some? No, gold is so really strong up 21 at 1723 with silver. Silver up 0.46 at 21.055. You're looking at the dollar pulling back. The dollar is down 67 ticks at 120.99. Crude oil. Crude oil is having a very strong day. It's up $1.80 at 85.42. The TLT bonds, bonds are just kind of stuck up 38 ticks. I'll be back with the Tiger Technicians Hour. I hope you can stay. I hope you can call my daily newsletter. See you in a moment. That's the Tiger Technicians Hour coming up.


Good morning, dear friends. I am Dr. Sachin Gengze, head of the department electronics engineering at Valkan Institute of Technology, Seoul. In today's lecture, we are going to have a look at some more characteristics of op-amp. Since last few sessions, we are discussing about the different characteristics of op-amp. Today will be the last session about the characteristics of op-amp. The learning outcome of this session includes, after this session, the student is able to explain few important DC and AC characteristics of practical op-amp. The content include important DC characteristics of op-amp and important AC characteristics of op-amp. As we know, operational amplifier is directly coupled high-gain amplifier and it is available as a single integrated circuit or IC. It is a very versatile device and we can design different applications that can perform mathematical operations like addition, subtraction, multiplication, integration of analog signal and op-amp can also be used to amplify DC and AC signal. We can design different applications like oscillator, active filter, comparator, regulator using op-amp. In the last few sessions, we have discussed about important DC characteristics of op-amp, which include input bias current, which is nothing but the current entering into the average of current entering into the inverting and non-inverting terminal of op-amp. Input offset current, which is an absolute difference between the current entering into the inverting and non-inverting input of an op-amp, differential input resistance or input resistance, which is nothing but the resistance between the two input terminal of the op-amp, that is inverting and non-inverting terminal. Similarly, the capacitance between these two terminal, the equivalent capacitance between these two terminal is called as an input capacitance. As we know, we have two pins dedicated to 741 like op-amp, pin number 1 and 5, where we can connect the pot and can adjust the output voltage, offset voltage equals to 0 and that voltage is the input voltage or rather the voltage between the pin number 1 and 5, which is required to adjust the output offset voltage equal to 0. The range of this voltage is called as an offset voltage adjustment range. The common mode rejection ratio is an ability of the op-amp to reject the common mode signal and amplify the differential signal. Input voltage range is the maximum voltage that you can apply, maximum common mode voltage that you can apply at the input of the operational amplifier and supply voltage rejection ratio indicate the ability of the operational amplifier in order to reject the changes in the supply voltage that is plus VCC and minus VEE. So, these are few of the characteristics that we have already discussed. Let us go ahead and understand few more characteristics of operational amplifier. The next characteristics is called as the last signal voltage gain, which is defined as the ratio of output voltage of the op-amp divided by the input differential voltage. So, a is equal to V0 divided by VID, where which can also be written as V0 is equal to a into bracket V1 minus V2, where V1 is the non-inverting input voltage, V2 is the inverting input voltage of op-amp and V0 is the output voltage. A is called as an open loop gain or which is also called as large signal voltage gain and usual value of A is very high. For example, for the op-amp like 7 4 1 C, the value of A is 200000. We can understand this large signal voltage gain using the equivalent circuit of a practical op-amp also. As you can see over here, the input at the non-inverting terminal is V1, that at the inverting terminal is V2, the differential voltage in between of this is called as a VID and the input resistance is R i. Now, then this block indicate or rather this indicate that the op-amp is able to amplify the differential input voltage with a large signal gain of A. So, if I look at the output of the op-amp V0, V0 is going to be A into bracket V1 minus V2 or V0 is equal to A into VID, where VID is the differential input voltage. The same thing can also be understood using this voltage transfer curve. So, on x axis, we have a differential voltage on. So, this indicates a positive differential voltage. It means that non-inverting input is greater than that of the inverting input. On this side, you can see that the differential voltage is negative. It means that the inverting input is greater than non-inverting input. So, x axis represent the differential voltage, while the y axis represent the output voltage of an op-amp. So, as you can see, when the differential voltage increases, the output is also increasing and after some time, whenever the differential voltage is greater than this particular voltage, the output of the op-amp goes into the positive saturation. Similarly, when the differential voltage is negative, up to certain point, you get an output which is linearly proportional. And after this point, the output of the op-amp goes into the negative saturation. Now, the slope of this line, the slope is nothing but the ratio of the change in the output divided by the change in the input. So, the slope of this line is nothing but the open loop gain of the op-amp, which is going to be very high. So, you can imagine, if I have the slope of this line, which is equal to 200,000, this line is going to be very steep. And even a small differential voltage will drive the op-amp into a positive saturation or into a negative saturation. So, this particular diagram is called as the voltage transfer curve of a practical op-amp. The next parameter or the next characteristic of an op-amp is called as an output voltage swing. Output voltage swing indicates the value of positive and negative saturation voltage output of the op-amp. And we know that it is never going to exceed the limit of the supply voltage of the op-amp, which is nothing but the plus VCC and minus VEE. So, theoretically from this, even theoretically from this equation, for example, if I assume A is equal to 200,000, and suppose V1 is equal to 2-hole and V2 is equal to 1-hole, then one may say that the output of the op-amp is 200,000 into 1, which is equal to 200,000-hole. That is not possible because the output of the op-amp is limited by output voltage swing, which is always lesser than the supply voltage. So, that voltage, the saturation voltage of the output of the op-amp is called as the output voltage swing. For 741C, output voltage swing VOMax is guaranteed between plus 13-hole and minus 13-hole. The next parameter is called as an output resistance. Output resistance R0 is the equivalent resistance that can be measured between the output terminal of the op-amp and the ground. And as we know, the output resistance of any amplifier is supposed to be as low as possible. And for op-amp also, it is very low. For example, for op-amp 741C, the output resistance is only of 75 ohms. So, these were some of the DC characteristics of an op-amp. Let us have a look at a few AC characteristics of the op-amp. The very first characteristic AC characteristic of an op-amp is called as the transient response. Now, we know that for any of the amplifier or any of the circuit, if the input is changing, the output is also changing and the measurement of that is called as the transient response. The response of the op-amp when the input has reached to a steady state value and remain at that level is independent of time and that response is called as the steady state response. Similarly, the transient response of an op-amp is characterized by two factors. One is called as the rise time and the second one is called as an overshoot. What is a rise time and overshoot? The time required by the output to go from 10 percent to 90 percent of its final value is called as the rise time and overshoot is nothing but the maximum amount by which the output deviates from its steady state value that is called as an overshoot. Usually, overshoot is measured in terms of percentage and for 741C, the rise time is 0.3 microsecond and overshoot is about 5 percent. The next important parameter of op-amp is called as the sleeve rate. Sleeve rate is defined as the maximum rate of change of output voltage per unit time and it is usually expressed in holes per microsecond. So, sleeve rate is defined as a dv0 by dt where v0 is the output voltage. So, dv0 by dt represent the change of the output voltage with respect to time and it is always indicated as the maximum value. The sleeve rate is actually indicating how fast the output of the op-amp can change in response to the input and for a given operational amplifier the sleeve rate is fixed and hence that puts a limit on the high frequency signal that we can use with that particular operational amplifier. For example, for the popular op-amp 741C has a very low sleeve rate of 0.5 holes per microsecond. It means that the output of this op-amp 741C cannot change by more than 0.5 holes per microsecond. Dear student, let us stop the video and answer this question. Now, the question is as we know the 741C has a low sleeve rate of 0.5 holes per microsecond. Do you think that it put any limit on the frequency of the input signal for 741C and if yes what that limit is going to be and can you please calculate by assuming certain value of the saturation voltage of the output of op-amp positive and negative saturation voltage can you calculate the limit that can be put on the frequency of the input signal used with the 741C. Lastly, to end this session we are going to compare the characteristic of the ideal and practical op-amp. For example, the voltage gain in case of ideal op-amp it should be infinite, but in case of practical op-amp it is very high. A typical values include 10 raise to 5 to 10 raise to 8. Input resistance of ideal op-amp is also infinite, but practically it is going to be not infinity, but it is going to be very high between 10 raise to 6 to 10 raise to 12 ohm. Output resistance of an ideal op-amp is 0, but practically it is not 0, it is very small say 75 ohm for 741C. Bandwidth is supposed to be infinite for an ideal op-amp, but we know that for any amplifier the gain bandwidth product has to be constant and that is why if the gain is very high practically the bandwidth of an open loop op-amp is going to be very low. And lastly the output offset voltage is expected to be 0 for ideal op-amp, but for practical op-amp it is not 0, it is infinitely hold. So, with that we come to the end of the today's session and I am leaving you with two questions. The first one is that what are the different AC characteristics of an op-amp and how the different AC characteristics govern the choice of the op-amp. We know that many op-amps are available on the shelf and which of that we are going to use for a particular application. So, how these AC characteristics decide which op-amp to be used for a particular application. So, references for today's session are the two books one is by Ramakan Gayakbar and the second one is by Roy Chaudhary. Thank you dear student for Patient Listed.