What's up guys? Welcome to Roderite. We're out here with a bunch of FPV pilots and we're gonna play some quiet games Okay, so the way this is gonna work is it's gonna be an elimination style of rounds So there's gonna be three rounds total in the final round There's only gonna be four pated the first round is gonna be king of the hill style perchin So your goal your goal in one minute is to perch up there on that perch stack Only three people at the end of one minute are gonna move on the goal is to smash the other quads off of there And make sure that you're on there at the end of the one minute sound simple Alright, let's do it So my strategy is I put a really big battery on my drone, and I found the strongest props I could find. It's heavy now It's durable and it's gonna win for sure The plan is to perch and then the power up to 1200 max so no one can see it. All right. I'm ready In the rock We got all five up at you off the start You got three approaching the first to land on it me. I'm up there you ain't messing with me. I am locked That was you you landed on top of me.  No I was out what happened? What happened? I crashed I got thrown up. There's three. That's three up there clean Well, no, not yet. There's 30 seconds 30 seconds. You guys can knock each other off Seven six five. I got one simple strategy and that strategy is just to be cold-blooded There ain't no love out here on these perches. I actually have no strategy we We scripted in a win for me, so I'm gonna go on no matter what so here we go time already in three two one Who's gonna be the first one up? Who James is like real steady approach He's on it Happened Okay, so Okay, so we predicted that this could happen that More than three people would somehow all end up on the box because no one wants to smash the quads off So long story short, we're gonna do a 15 second sudden death the pilot to make it on move on But you only get 15 seconds, so it's basically just a race to see who can land on the block We're gonna get these guys regrouped and we're gonna go again All right, so the captain Kazi strategy is to kamikaze strategy I'm just gonna full blast. I got the tank. This is the mission for the job right here. This is the tool for battle I'm just gonna take the blue guy out Vanna been over. Okay, so I really don't have a strategy for this Watching the first two rounds go. I realize that being the first one up there is not always the most advantageous thing Just like staying ready to go. I'm gonna try and like push other quads off while I'm up there I'm not just gonna be happy and content with one of the quad there I'm gonna try and like be pushing people off while I'm up there You know I can hear your strategy. I'm standing right here. I don't get it's fine. That's all right Here we go. Let's see. I see a couple. I see you. I'm up. I'm up. I'm up Oh, another one too. Oh, this is good for me. You're on top of me. We're lucky Just chill. I'm chill. I'm chill. Just chill. Let's just chill, Kazi. Dude. Oh my god. Stay ready.  What's the time? What's the time? Stay ready I'm dude, he's right right on top. Oh, oh, do that. We're good. We're good Okay, so we made a rule that if more than three were on that we were gonna sudden death the Remaining pilots right Eric was on however his quad is destroyed. So unfortunately kind of solves itself if you can't fly and try it again That's what it is. Sorry. Yeah, no problem. But dude, thanks for participating. Thank you for Thanks for having me. Thanks for hosting us as always by the way guys This is Eric if you haven't seen him in previous episodes This is his creation here, and this is the fbv park up in the Pacific Northwest. Is that what you call it? Uh, yeah, the Northwest fbv park, something like that. Northwest fbv park guys So we're very thankful that he would allow us to come out here and just let us fly. So thanks, Eric Sorry you're out, but we'll do some flying today. Okay. So congratulations You guys all made it to the semi-finals, but only four people are going to move on So we have another complete new challenge where only four will make it This is going to be the power loop challenge. So you're going to power loop underneath the slow sign Over the slow sign but in between the branches. Here's the catch. You got to do 10 power loops total Five each direction and there's going to be four guys going at the same time So there might be quads doing it like head-on Now if the thing if you crash and you can get back up, that's great You just have to complete 10 total power loops But five of them have to be from each track But the first two guys from each group to complete their 10 power loops Move on to the final and we'll have a final four and I'm excited for that one as well. Let's do it This one's gonna be Someone just eat an enemy Two I got five on one end. It's really hard. It's way harder than I thought it would be I thought it'd be really funny off the start to like give a really big launch ran straight into a tree I totally thought my run was over at that point. I was so upset It was a lot harder than I thought it was gonna be like trying to like avoid the other quads It was it was tricky. It was really tricky. Okay, so congratulations guys the four of us made it So the final one is going to be a little bit different than previous challenges Normally in all of our challenges, it's one winner and like that's it So in this case, it's going to be a team race, but not just a team race. It's going to be two pilots One quad So the way we're going to do the teams is it's going to be the pilots from each round So Shane and I are going to be flying one quad. You guys are going to be flying the other I feel I feel pretty good about Listen, my rates are 1200. What are yours? Oh, no What are your rates minor 12? Okay, minor like okay, so we're both in the same Okay, so let's fly my quad because I will never I'll suck but I could do yours. Have you guys ever done two pilots like one radio? No You guys have never okay, so I've done it once and I will tell you Whatever you think is like the best combo in terms of like what you need to be on is probably not Shane we're gonna do this. Let's go Let's go do it. We'll let you go design the course of this and we're going to be designing a course For for the guys in this final round of the games And I don't know should I make it easy? Should I make it hard? It's got to be challenging for alex and if it's challenging for alex, it'll be challenging for the rest All right, let's go do it.   You run it back I think we should start where you're going to be better just so we see that we so we have some confidence Then we'll switch So i'm going to take the right stick So that's going to take the left I'm going to be working throttle So we're going to throw him on the main goggle So he has the max connection and he's going to be one the one that's leading where we're going And I'm just going to kind of correct where it needs to be And you'll have a little bit more latency a little more latency but He's guiding us so we should be good. We're not really the fastest pilots, right? We've got a racer and this guy who shreds freestyle at mach 10 But listen, have you ever heard of the story about the the hair and the tortoise? Who won and then There's the tortoise is the tortoise. We're going to take it slow Steady and really what i'm hoping is that the animosity between alex and shame because shame beat him in west coast Throwdown freestyle profiles. Yeah, that that will just tear them apart for sure. Hopefully they start arguing Yeah, and alex has kind of a big head so they can't get close enough to reach his hand on the stick That's another thing going for us. I think Why staying up in the air is just a big thing like the good thing is like my natural is left So it's going to be a mostly a left turn course. Yeah, which I think favors us and I like turning left as well Um, I think we just need to like really line up all the the difficult sections Like the dive as well as the power loop right just like take our time there because I feel like our Like comfortable speed is going to be like them really pushing hard So if we just fly like a smooth face we can push it if we I did notice one thing we need to watch out for is on the Big dipper there's a tree branch coming up the hill So we need to try to keep it kind of low not like not like boost up too high And I like staying low too and like boosting up and then going into it. We doesn't matter which way we exit Um, yeah, just not crashing. It's a big thing. Yeah, I would say like pulling out on the big dipper Even if we overcompensate on throttle just to stay off the ground it's going to be worth it. Got it. I always got to pull out Yeah, always Don't put that in the episode I was not expecting us to be that I mean I was not ever interested Are you ready? Arm your quad Arm your quads on the tone That was way too low. Just go straight and then turn right No, don't go for it. Don't go for it. Here we go. Right, right, right, right, right, right Okay, three, two, go Yeah, that's good. That's good. That's so good All right, we'll sketch you. All right, here we go and around Okay, how do we go? Oh, you did it. Okay. Good. Good. Go, go, go, go, go Sorry, ma'am. One lap.  They're fast too though. Ready? Yep All right boys, that was fun We just had to like just go for it. Yeah, like there could be no hesitation. We just had to go But that last ride was beautiful. They were done. They were done now. I'll give them ready. All right. Wow All right guys, so that was quad games of the amazing community. I had a lot of fun. What about you guys? If you guys want to see more episodes like this, let us know in the comments down below Be sure to like the video subscribe if you're not already turn on that bell to know when we post videos like this And I had a great time guys. Thanks so much for watching. We'll see you next time


I am excited about Brian Flores joining our coaching staff, given his history of developing and teaching defensive players during his time in the NFL. Brian's resume speaks for itself and I look forward to him adding his expertise to help our team. That was Steelers head coach Mike Tomlin speaking about their new, let me read the title word for word, their new senior defensive assistant slash linebacker's coach Brian Flores. YouTube team keep it clean, what's going on is engraving here with another video. And in this video, I'm sure this move has a lot of Ravens fans, pretty upset. And the reason I use the word upset is because there were a whole lot of Ravens fans that when the Ravens let go of Wink, well, when they kind of kicked them out, that they were like, hey, we should hire Brian Flores. We saw what Brian Flores did to us in Miami. He completely exposed our offense, exposed our lack of adjustments, exposed everything. We couldn't do a thing. Couldn't do a thing. And a lot of Ravens fans are like, all right, we should bring him on. Cause the Ravens, they hired the Dolphins outside linebackers coach to coach their outside linebackers. They did that, but they like, ah, Brian Flores, nah, nah, nah. But the Steelers were like, all right, hey, we'll find a spot for you. We'll find a spot for you on this team in this front, we got you Brian. And this is a move that it's a good move for Flores. It's a good move for the Steelers and they can help each other out. And I'm gonna tell you why. Brian Flores, he was one of the hottest names as a future head coach of another team after the Dolphins let him go. But then of course, after the lawsuit, we know that lawsuit that was taking him out of the runnings. We knew as soon as he announced that lawsuit, it was like, all right, well, I guess he ain't gonna be a head coach no more. It ain't happening. So since he wasn't gonna be a head coach anymore, I was thinking that he was absolutely done in coaching period. But what this move does, this allows him to remain a coach, but it also allows him to continue to build up his resume. It allows him to, because this whole senior defensive assistant and lying back as coach, this is temporary. This is temporary.   Then he became a defensive coordinator.  That's what this is setting it up to be. That's what it's setting it up to do. And as far as how he can help the Steelers, we know the Steelers, usually their defense is something serious. But now with Brian Flores, everything that he brings to the table, especially defensively, like you already had a great pass rush. I'm a Ravens fan. I think I would know. But Steelers already had a great pass rush. Brian Flores just adds to that. And as far as from all point of view, as Ravens fans who have to go up against the Steelers at least twice a year. Ravens already struggled with the Steelers as is, already struggled with them. But now you add him as a defensive assistant. You add Brian Flores' mind to that mix. And again, that was probably in my opinion, that was the worst offensive game for the Ravens all season long in my opinion when they played against Brian Flores and the Dolphins. Now something to think about, do you think that with Brian Flores and the Dolphins that the Steelers, like their players are not better than those, well, cornerback secondary wise, Dolphins got a pretty good secondary. But they really maximize their talent. That's what I'm trying to say. They maximize their talent. So Steelers, they already have a lot of talent. So if that talent continues to get maximized then it can be even better. Now, this is a reunion as well. This is a reunion between Brian Flores and Minka Fitzpatrick.  But I'm sure it'll be fine. Because we know after that Lamar Jackson 5 in 2019, I believe that was Brian Flores first game as Dolphins head coach. I'm pretty sure it was. In 2019, we won against the Ravens. So you know, the AFC North Games against Baltimore, he gonna be having a little grin on his face like, oh yeah, these dudes, I already got these dudes last year, but I'm trying to get them again this year. So hopefully it doesn't work out that way, but we'll see how it goes. But again, this is just, in my opinion, I think this is just something that's temporary for him. But bring you on as a defensive assistant.  He may take on some other role and then he ends up getting promoted. Whether it's within the Steelers organization, to be like an assistant head coach, or it's without, I mean, excuse me, not without, it's outside the organization as an actual head coach again for another NFL team sometime in the future. But this is a good move from Pittsburgh. It's a good move for them. It's a good move for Brian Flores to get his foot back in the door.  Team keeping clean, I appreciate y'all. I love y'all. I hope y'all having such a great Saturday.  With how Brian Flores, he's a defensive assistant. He's not a head coach. He's not an offensive coordinator, just a defensive assistant, but you never know. You never know. And I'm sure the quarterback wouldn't be opposed, but there was all the talk about Brian Flores, how he felt about tour, that he didn't want to a tour was not his guy. He was not a tour near. But he was somebody that was a heavy advocate for Deshaun Watson. He wanted Deshaun Watson on the Dolphins. He advocated it, pounded the door for it, pounded the table for it, but it didn't happen. What if, what if, what if? Because there was that rumor that came about that, oh, Deshaun Watson was looking at the Vikings and some other team, oh, the Bucks, that was the other team.  And even the Vikings still be a nice spot. But what if with Brian Flores there, Mike Tomlin there, the defensive players that they got, and they would of course need to add a couple of offensive players like some wide receivers, Juju's a free agent. We'll see what happens with some other guys there. But what if Deshaun Watson is interested in Steelers, but the Steelers are also interested in Deshaun Watson. What if, oof. That would be something. We'll see what happens.  I love y'all team, keep it clean, subscribe, turn on your notifications so you don't miss not one single video. And just like Brian Flores is when it comes to being a free agent coach, I'm out.


40 Jones finally my boy has a sort of cool final boss looking form ladies and gentlemen Welcome back to the channel. My name is Jack the buster I should know be I'm watching more one piece today And we are in the heat of the fish man island arc with Neptune now on the chopping block Jim may on the way almost there and Luffy supposedly in the dirt because he lost the Jim Bay I don't know embarrassing. I'm gonna need a good explanation for my captain We're gonna hop right into if you knew the channel. Don't forget to drop a subscription. It is free and let's get started I Don't know if I should be hyped for Jim may to get to the plaza or I'm scared. They'd be both What is this fake Neptune? Is it to bait them in oh?  That's it. I'm disappointed beyond belief Dang bro got them all in the chopping block. He's about it in the whole bloodline, bro Cuz of the drugs man. It's a cheat code No one left in this country clueless He's right though. Their powers are fake basically. I'm glad Neptune said that if that's really the extent of Jim Bay He's just like locked up now. I'm gonna be so mad. Oh, yeah, what up?  There's no way You're so much stronger than this. Oh my god, bro It's just as he was talking about it Do he's concerned about most you may do unless he's talking about megalo man. What is this? What happened tell him horny that was going on Boy fake news travels very quickly I wonder if the straw hats are still in the back of a horny's mind though, especially because of how bad for cut him up Okay, yeah, he's open about it Yeah, they're gonna try to go there and get in first to save their friends But Brooks gonna get pop a good of the free Usa, Pem and Zoro So I think they'll be free by the time Luffy and them get to Rigu Palace. I'm hoping Yo, the fish mom kind of foin Oh Wouldn't this have been like a global issue that that many humans went missing What is the plan go have all of them killed 30,000 people? 100,000 alas. Oh my gosh Wait, the Horde's army is way bigger than I thought I know we saw a lot of them in his like whole little hideout thing but this is insane Oh, man, it does make it way complicated though If the straw hats have to take on this many people because how are you able to effectively and without making yourselves look horrible by Taking down that many fishmen He's just got his arms up He's literally just trying to like full reset the island On the other predictions madam Oh He noticed her up there She bad bro Yeah, oh man Luffy not you oh, but it's gonna hurt his ego that she says he's not the one meanwhile where is that goober Dang bro the bubble pop she started to be like, huh, maybe maybe it's a good thing that he will That's got a scare hordy a little bit though because everybody here knows how true to her predictions become Oh, okay, Hordy now you acting like the big bad.  Hey, who's her brother?  I'm gonna hold out the rest of the arc for one That would be insane It would be apropos you without deep of a wound he has in this entire country in this entire plot her being his sister is crazy though It wasn't a human He shot her and blame the human. Oh my god. I can't believe he would admit that though. Oh my god I can't believe he would admit that wouldn't that change some people's perspectives and minds He's so ego and braggadocious. He has people to know that he's the one that brought her down He paid the human to do it.  I mean technically yeah child could have done it. There's no guard around her if you're careful Geez man. Oh Wait, he is the one that burned the papers. Ah, he paid him to burn the papers so it caused emotions that he could shoot her God thanks, but he actually was the one that pulled the trigger Sheesh, man. I didn't even consider that notion. I don't know why He was right even a child could have done it. He's trying to just burn the papers brother Horty for real like changed the course of the entire Fishman world I still think it would have helped his cause more though to have people still believe that it was a human that did it Like yeah, he reversed her actions here now But some people like site it with Horty because of what happened or what they thought happened Then like humans because of what they thought happened Why it's not time for the execution we saw like over an hour. I think I don't know time passes very oddly in one piece He's trying to piss her off I Feel like he's gonna upset her to the point where the sea kings do come out But his ego's gonna make him make a mistake as if he hasn't already I think he's straight up just being bragged those just because he thinks he's completely one like there's nothing they can do anymore He just is counting the straw hats out. He wants them to revel in it before he kills them I Brother he's gonna over stop. She looks surprisingly calm Shockingly maybe because she knows how important her role in all this is Wow She's oh What ah she knew how would she not have told anyone? Mysterious Yeah, like Noah's Ark basically That's a pretty big leftover from oh my gosh wait so he can throw things at it or so he can throw that What he's gonna take the entire ship Okay, now these bad boys are making a move money moves. He ain't got girl problems no more Throwing the Noah at Shirah. Oh my god brother is has lost the plot Look at his legs half the size of the island. It's like a new okay. I like this. This is nuts. This is madness How fast will it move what is Hordie Jones think about this Hordie Jones would be mad No, who did he say made the eye made the maid Noah's people want to go everyone on the island just came together and made it Okay, sure man. I don't know why that seems like just like throw away I feel like it's way more important than that cuz like why would they all just make this ginormous ship anyway 553 Let's let's see if we talk tosses this bad boy. Let's see if we even get to check in with Luffy When did my camera freeze at what point did it freeze? Tell me it wasn't that long ago, please The fact of the giant gigantic ship is just headed towards them right now it just makes us so much funnier I just want to see Hordie Jones reaction to it Van der Decken could change all this not even the straw hats a Few years after Megalo Everything this shark so Megalo held in a secret this whole time Did he see it happen? What are you just sat with that? Oh? My goodness. Oh Adios meal.  I don't know about this son I get that she's trying to be the bigger person, but this is this is the entire future of the island at stake But it's not about getting angrier or hating. It's about people holding people responsible for what they do Brother, it's not an anger.  That's why she's so emotional That is pretty stand-up at the very least Yeah, that works out for Hordie Hey Megalo, that's what I'm saying even Megalo kept his mouth shut I'm surprised Megalo didn't tell anybody else like maybe the army or something Megalo spin was not in that pinky promise brother He allows the blame to just sit on them have them blame themselves Stimey is that a word? He can let her blame herself dude. I guess he's gonna push her too far though She's going like I have an outburst and then the sea kings are gonna come calling.  Can we have a status update on like Luffy the straw hats everybody?   What would you say? They're really contrasting ones the white background Either someone has to come flying in oh wait. What was that in front of her? It was like on the ground Oh, oh Wait Are you guys looking forward to it now?  They're actually rooting a loopy to show up Oh my gosh, it's showing the shift in the people's perspective More people would rather them come and cause chaos than whatever Hordy Jones plan is execute As if Louvi would ever want to destroy anything boy I feel like Jim base regretting everything now seeing the people's perspective Oh, it was a medical thing from the doctor and before they actually hear or he he actually hears them It's gonna piss Hordy off Ah But he's just lifeless like I've done all this work to become the villain they're cheering on another villain to show up I don't know. I still disagree with the whole Shirahoshi thing. I get the promise, but megalo come on, bro Let's tell like a general or something He's got to get here soon we've been seeing him in like five episodes Hordy language Wait, wait, he's sort of about to do it.  Oh, she's gonna call like the sea kings anything Oh No, sure.   It's a miracle So I'm guessing Jinbei didn't know about this. I don't know if Shirahoshi even did You're out already. Oh This was part of their plan Jinbei didn't know what you all Hey Were they all inside megalo? Was she invisible Oh shoot gosh, you look good The letter she grabbed it. Oh my goodness brother you have one job the master thief. Oh Shoot the princes are freed.  There's my mom in the sky Sonny oh shoot There's my boy the sony can in We're making a flashy entrance.  Oh wait, you could snatch like Neptune and sure Hoshi get him out of there Think about to the palace of anything Let's go. Oh my god Like I said a Hordy's going to be so insanely angry. Everything's being snatched away from him So why did Jinbei when they were leaving say like I was tough getting it through to him Maybe like they just decided on this plan together Sonny just crashing down. So did they go to Ryugu and get Zoro and all them? There's chopper The chopper was still with all them. Yeah, they did oh my goodness 70 or 80 thousand I'm guessing I just said the whole thing of Brooke and then and Papago. Oh brother. Oh What are the straw hats are here? We get to see them all pop off finally? Oh man Oh, I'd be terrified of our the fishman. They don't even know what's coming Ain't no way to send a goddamn chance against the straw hats. Look at this the insurance Just reassure them Luffy It'll all be revealed in due time Got that walk This is sick man This is it I get flashbacks like the walk to our along the walk to Frankie's old place I kind of wish Frankie was part of the walk Jim base free now too. Oh shoot God, they know how to do these moments so well with all of them Yeah, I hope for Luffy to decide he said watch me, baby. Holy what a what an Fantastic sequence of events bro. We didn't waste any time seeing them You know get reconnected with Zora and all of them It gave us the shock of a lifetime with him bursting out of Megalo perfectly done I mean the pacing of this entire arc has been fine so far But that was it that was fantastic in the way that was done Luffy getting a fat hit on this big bad villain of the arc Just start off everything was it was impeccable I cannot praise these decisions enough in terms of the writing and all the straw hats are here and it is game Time, baby. Yeah, I love that walk. I hope they never do away with this entire entrance thing with the walk I didn't think it would ever be a recurring theme like whenever they first did an Arlong like the walk to Arlong Park I was like, that's a really cool moment But after this one I've started to recognize it's become sort of the straw hats thing because we know them very well But I try to put myself in the perspective of like one of these villains seeing this this group walk up the sheer power You just see radiating off of them and with their confidence It just makes me that much happier to be rooting for them, man But now we've got more lore more answers Hordy Jones being the actual one to shoot Otohime Assassin Otohime changes a lot in terms of probably the fish people's perspective But yeah next episode I'm guessing it's all going down this this fat war is going to begin and we're really gonna see the straw Hats hopefully start to pop off but guys that has been it for my reaction to one piece today I hope you did enjoy drop a fat like on this one if you haven't already let's try to hit one billion likes I'll see you guys in the next one. Peace. Peace


Hello, my name is Jim Davies. I'm here at Olympic Hall Studios today to do some live recording of a track from my new album. All the bands I've played in since I was 21 have been electronic based. So I've always had to be aware that what I'm playing has got to get over that massive amount of sub bass, a lot of electronic drums. I sort of learned quite early on that you can't always play what you want to play over that style of music. Which I think is why sort of a lot of the lead sounds I use are very harsh and shrill. When you're putting guitar over electronic music you find that a lot of the time you have to play quite sparse. You can't shred over the whole thing and it's just not going to work. So I tend to try and be quite liberal with where I put the guitar so it actually works and stands out. The whole electronic music angle completely changed how I played guitar because I was just so bored of playing rock riffs and trying to play fast. I sort of sacked all that off. I suppose I wanted to be able to play keyboard and the synth side of stuff and I didn't really understand it that well at all. So I just remember thinking I'll try and do a bit of that on guitar. So I just copied sounds and got into weird peddles. The prodigy ended up playing at my university and I went to see them play. I just asked a roadie where their guitarist was and they said they don't have one at the moment. So I just went home and done a really bad demo tape of me playing over Geoak Generation. I brought it back and gave it to the band and didn't expect to hear anything. But I did a couple of weeks later and they asked me to do a few gigs with them and it just turned into playing with them for about a sort of a year almost. I don't tend to write tracks with a guitar.  I never ever do that. I never have. I always sort of write facing a computer, playing into a computer, jamming around, playing guitar parts over loops and riffs. It's a very different world playing over electronic stuff. The main amp I use at home in my home studio is an HT20 which is quite a small compact head because I go from the emulated speaker output out the back. I love the sound of mic'd up guitars but a lot of the time it's just hard work to be able to crank it that loud and be able to record it.


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And so that's how you solve part two of the homework assignment. They're laughing, so it's very, very easy. Okay. Cool. So we will go back to modern cryptography. So we looked at ECB. So what was the core idea behind ECB? Why do we need this? Why can't we just use DES or ADS or whatever encryption algorithm? Yeah, so the core idea what we have is we can take a key. We have this basically in black box where we can take a key. We put in data. We get out cipher text. We actually didn't talk about some of the other properties we want from this black box DES. So what are some things that we want? I think we talked about we shouldn't be able to brute force the key or derive the key directly from the cipher text. What else? Yeah. We shouldn't be able to know what the clear text is given this cipher text. We shouldn't be able to, wait a second. So we shouldn't be able to take the cipher text and go back to the data, the clear text. So it's a one way without the key. What else? Yesterday there was a penguin example where even though the cipher text is not really related to the clear text, there's still a pattern that's apparent because of how it was encrypted. So the way to think about this is think about it through the different types of adversaries. So let's say we have an adversary, a chosen plain text attacker. So they can choose their plain text and get the cipher text. So in that case, what's their goal? Have a plain text and a cipher text. The key. The key. To get the key. Right? So one of the properties there that would be nice to have, and this will come up again a bit later, is, and this is again not being able to go back from the cipher text to the data. So what if I change one byte in? So what if I do AAAAA as cipher text or as data and then I get that encryption? And what if I do, actually I don't know if this is one byte off. We'll say it's one or one bit off. We'll do BAAAAA and then encrypt that. What if the cipher text is only like one bit difference? Not good. It's probably bad, right? Why would it be bad? Because it, or it could be easy to go from cipher text to plain text. If you know that if I change this bit in the data, this bit in the cipher text changes, you could probably very easily go backwards. Which is actually very similar to what we have in like the Caesar cipher or the Visionaire cipher. So you want a one bit change in the data to produce basically a completely random cipher text. That was just something we didn't talk about. But going into these block modes, the core problem is we have 64 bits of data. We often want to apply our encryption algorithms on multiple chunks of data. And so the most natural way to do this is to just split up the input into blocks and then run each of those blocks through DES with K. What's another? So what are some benefits of this approach? Can we talk about that? I don't like some. Yeah? It's easy. Easy? Easy to implement, easy to describe. And what other ways is it easy? What is this computation of the last block depend on? Just the block and the key. The block and the key? What about this computation in the middle? Same thing. It's blocked and it's key? What about the first computation? It's blocked and it's key? Could you do all of these in parallel? Running them at the same time? Yes. This means you can take advantage of massive parallel computation like GPUs or even modern CPUs that can have 40 cores and you can run and can do each of those blocks in parallel. This is actually one of the major benefits here is using that. But as we saw, the problem then becomes every block, so given a specific key K, identical blocks get encrypted to identical ciphertexts. This encryption algorithm is deterministic. If the key is the same and the block is the same, the output must be the same. Otherwise we couldn't decrypt and we'd have huge problems. And this results in that awesome picture of tux, the Penguin, where you can take the raw byte, the raw RBG values of tux, you can encrypt them and you're encrypting this to send somebody this message and you want nobody else to see what you're sending. But if you just actually look at that image, you can see that every byte block has basically been transferred to this gray block because every block that's identical gets encrypted to the same ciphertext. So you can still see the patterns here at the block level rather than at the granularity of the character, of the image itself. But you can still get an idea of what the message is that's being sent. Does that make sense? Cool. So how did you fix this? Yeah. Or what's the key? Sorry, yes? Every block is a different key. Okay, you could make a different key for every block. How long, what size of key do you need then? Would you need a key the same size as the data? Possibly. If we make the same... Sorry, before thinking about solutions, let's talk about what's the core problem here? That the ciphertext maps to the same thing, or sorry, that the blocks map to the same ciphertext. Every block maps to the same ciphertext, right? And actually the nice part that we got with parallelism is actually the downfall here because all of these things can be computed in parallel which means none of these blocks actually depend on each other. Cool. Okay, so now solution. What do you think? We make it depend on the previous computation in some way so that way the ciphertext isn't exactly the same. Right, so we can make it depend on the previous... So one idea would be instead of 1k, let's use nk's where nk is the number of blocks we have. The problem there is the kind of nice thing about this is the security of this depends on our key. So now we need n keys that we have to somehow securely transmit to them. And at this point we're transmitting them n times 56 bits of information securely when we're trying to communicate to them n times 64 bits of information securely. So at that point we've kind of already done that. Any other ideas? Yeah. Just speed the ciphertext. So we could maybe mix this ciphertext in with the key. We could also... Another idea would be to mix the ciphertext in with the block. So you... And actually this is exactly the other style of mode which is cipherblock chaining mode. So the idea is... Oh, it looks like my xor is messed up. So you take the first block, you encrypt it with the key k. You get some new ciphertext. You then xor that ciphertext with the next block. Encrypt that to get some ciphertext too. So now what if this block and this block are the same? It'll be different. These ciphertexts will be different, right? And if you have the ciphertext, can you go backwards? What can't you go backwards of here? It seems silly because you have all the ciphertexts. So how come you can't derive the...  Because you don't have the key? You don't have the key. Yeah, exactly. So you think of this as like a one-way trap door. You can go through it, but you can't go... Without the key you can't go backwards through it. You can't derive this input. And what is this input? Is this input the block? No. The ciphertext. It's the xor of the block with the ciphertext. And then you just do this. So this is the chaining idea. So now you have this nice property that even if the blocks are different, now the ciphertext... All the ciphertexts will be different. Except for what? The first one? The first one. Yeah, which why would that be a problem? Because if they felt they knew the key, they could check it for the first block. So if they think they know the key, they could... Well, maybe we'll go and do the reverse, but basically you have all this ciphertext. You can go backwards and do the decryption. You take the last block. You run it through DES. You xor it with the previous ciphertext to get the plaintext block. And then you just do that backwards. If you think you have the key, you can easily do that. So what does this ciphertext correlate to? The original plaintext. Specifically the original plaintext. So think about what does this ciphertext correlate to? The previous ciphertext and the plaintext. Yeah, the previous ciphertext and the plaintext. So it's kind of a mixing of both. So it's going to get randomness from this ciphertext. But this ciphertext is coming from where? Just the plaintext. Just the plaintext. So now every message, and remember one of the attackers we're kind of thinking about is a chosen plaintext attacker. So I may be able to try to figure out what your block is or what the messages are. So let's say I have some messages I've stolen from you. I think they're saying buy or sell. I could just with the chosen plaintext attack, I could encrypt buy and encrypt sell and see which ciphertext matched because the key is the same in that case. And then I could easily match those up. So you still have this problem of this first block that depends on that. So what do you do? From a concept, and if you think about it, so this one is different, why? So this one doesn't map one to one with exactly that plaintext because what happens? XOR again? Yeah, the XOR again, right? So the plaintext is XORed with the previous ciphertext. This ciphertext is different because this block was XORed with this previous ciphertext. This ciphertext is different because this block is XORed with this ciphertext. But what's there to XOR with this block? And so the idea is, well, we do want to hide what that first block is, so what if we randomly created a first block and then XORed 64 random bytes with the block and then encrypted that, and then that's that first block? So this is the concept of the idea of the injection vector. No, no, it doesn't sound like an injection vector. Initialization vector. There we go, initialization vector. That makes much more sense. Thinking portability analysis. Cool. So the idea is if this is random, then you XOR that with the block, and now what's the relation between the ciphertext and the initial plaintext? It should be no relation. It should be randomized based on that IV, right? So if you're doing the same blocks, as long as you have different injection vectors, then this ciphertext will be different. How would you initialization vector? How would you decrypt it if you didn't have that initialization vector? So how do you decrypt it? That's a great question. You have to keep both key and IV. You need the key and the IV, right? So you have the ciphertext, so you can easily decrypt, so with just the key, you can go backwards, get this block, you have this ciphertext, you get this block, and go backwards, backwards, and so you get to here, the very last block, you can't decrypt, well, you can decrypt it, but you need the initialization vector to XOR to get the original plaintext, right? So to decrypt it, you need the initialization vector and the ciphertext. So now what if somebody sees that communication, extracts, steals the initialization vector and the ciphertext? What can they learn? The first block, how do they do that? If they have this ciphertext, then they do what? They're not the first block, but they can determine what the first ciphertext is, but they already have it. They have everything here, right? They have all this ciphertext, they have the initialization vector. They need the key, right? They actually don't have the key.  Wouldn't it still be vulnerable to plaintext attack? Yeah, plaintext attack. Just like it was before, that was the whole point of making the IV vector. Right, okay, so then how would that work?  Ah, I see what you're saying. Could you have the IV, you have the ciphertext? Yes, it would definitely not fix that. Okay, so then the, so let's say not a chosen plaintext attacker.  Then you could figure out some or buys and some or sells from a side channel or something. So with the initialization vector, you then no longer can tell that the blocks, that the first blocks are the same. And that would prevent that. Yeah, so it actually doesn't prevent the chosen plaintext attacker. Good call. Cool, so now would you, yeah, exactly. So now would you, and essentially you can think of it as you're using the same scheme, but you're creating a random block at the start. If we want to guard the initialization vector, wouldn't that also sort of be part of the key? Yes. Because we also need to decrypt. Exactly, so if you need, if you, if this whole scheme relied on the keeping the initialization vector secret, then essentially it's part of the key, which we don't want to do because, and we don't need to do it, right, because for any other important thing is this initialization vector is random for every message. And that would mean we can transmit the key once out of band, now we both have it, now we can decrypt messages from each other. But if we had to do that per message, send a new piece of information out of band, then it's kind of a waste. Cool. And so this then gets rid of our, oh I don't have a picture of him, but this will actually completely scramble tux so you can't see anything from it. And one of the, so from these, so what are some of the pros here we talked about? What are some of the, what are some other pros of this design? Are there any? More secure in that you're not leaking any information about the entire plain text? What else? You don't have two keys. You just have the key. The initialization vector is public or with the ciphertext. So you would send somebody over a channel where it can be stolen, the initialization vector and the ciphertext. Similar messages don't produce similar ciphertext? Exactly, similar messages don't produce similar ciphertext and similar, even similar blocks within the same plain text will not produce the same ciphertext. Right, so you're kind of, and the whole reason why it's using this and the whole idea is that, and this is why, so this should be again another theme of why cryptography is difficult because you design this box to be very secure. You design this box such that there's no way to map these outputs. So if you're giving this ciphertext you cannot find this input unless you know the key. We'll actually see if it's not 100% the case with DES, whatever, you design this super securely. But you're using this a ECB mode and you're actually leaking information about your plain text because there's this additional operation of splitting your plain text up into blocks. And how just doing that actually introduces and can undermine the security of your crypto system. So what if the initialization vector is basically public information? Yes. What security advantage does it actually offer us? I'm a little confused because it seems like if they have the initialization vector and they have the ciphertext. Yes, what can they get? They don't get the block but they still even if they just have the ciphertext versus having the initialization vector and the ciphertext. There's no difference so we assume that they can have it because in order to transmit this message we have to send the ciphertext and the initialization vector. So because we're sending this over a channel and we assume that the adversary knows both and then we can say, well the security doesn't depend on them knowing both which is fine. But it still doesn't solve the problem of the chosen plain text attacker. Correct. Yes, those we have a problem. Why wouldn't we send the IV in the same way that we send the key? So the key, we could establish a key let's say at the start of the semester and use that to send however many messages we want and we're fine. But with this we have to send an initialization vector for every message that we send to each other. Cool. Other things? When you're programming, anybody use a library when they're programming? What kind of libraries? Collections? What else? Input output? Base 64. Boost? Base 64? Requests. Requests? We request a good one. Do you go through and read the source code of every library that you use? Of course. Do you read the manual cover to cover of every library that you use? Absolutely. Absolutely. Anybody ever use a crypto library? So a lot of crypto libraries actually, and you can see clearly from here of the two for security purposes which one would you want to choose? CBC. You should almost never use ECV because it introduces these vulnerabilities unless there was some reason that you thought you had to do it, but then you have to do other ways to try to mitigate the problems there. The problem was for a long time, security libraries, if you wanted to do symmetric encryption, they would default to... I'm losing my thing. Yeah, they would default to ECV mode and then you had to set a flag on a parameter to actually switch it to CBC mode. And this actually caused a lot of problems in people using crypto libraries because they think they're doing things securely, they're not writing the crypto themselves, they're letting somebody else do it, and then the API itself is poorly designed and the defaults are very poorly designed such that everyone uses the default parameters, and if you write it and it works to encrypt and decrypt things, why are you going to dig in and figure out exactly which flag you should set to put it in which mode? Or maybe you're reading it and you don't know the difference. What's that? Unless you took a class like this or did your own research, how would you know the difference between electronic code book and cypher block chaining? Anyways, this is my mini rant using programmer usability of APIs and libraries and how they can lead to security vulnerabilities. Okay, so one of the problems with DES as we kind of saw, the key size is actually too small and this seems kind of crazy, 56 bits, but computers, and this was again created in 76, computers are insanely fast, very, very, very fast. I don't know. So the key size for this and we talked about what lengths we were willing to kind of risk. So when we talked about, let's say, if you think back to like 1976 and you said, okay, I want a key size that's going to keep my data safe for whatever, a year or two years or something. And you did that computation in 1976 or let's say five years or even 10 years. What are you basing those numbers on? The what? The speed of the current computers and how fast they can compute DES. What are you not keeping into account? The future. The future, how fast computers can get in the future. And I don't, somebody can look up when Moore's law was first stated. Does anybody know Moore's law? Does anybody know the real Moore's law? I'm not the incorrect interpretation of it. So what's Moore's law that you've heard? 75? Yeah. Right about then? Okay, cool. What is it? That transistors will like be smaller or not, they'll be able to have like double the transistors in the same amount of space. Yeah, so it used to be for every 18 months I think. So the colloquial thing of this was every 18 months CPU speed would double. Right, and this is an exponential growth which is very fast. Right, so. And so if you don't keep that into mind when you're developing something like this and saying like how fast CPUs are going to get in the future they could reach the point where now people can brute force this or what if I just buy a million computers and have them all running in parallel brute forcing a key. Right, that could be something I could do if I was a government agency maybe with enough money. So hey guys, the real Moore's law is that for the same, like the density of transistors really doubles every 18 months. Or did, I mean. Anyways, now it's super complicated, yeah. For the DS key size. Does that mean, like what would the so like when it eventually became obsolete about how long would it take to brute force the keys? That is a great question. I don't know that up top of my head. I bet now, especially with like a GPU and stuff you could brute force it pretty quickly. I think, let's see. I mean I'm definitely with a desktop or laptop you can brute force a 32 bit value. I think 64 bit is also within the realm of possibility but I'm not 100% sure. So that would be something to look into. Oh, cool. Well, here we go. So the other thing, wow. So yeah, it seems like a really big number, right? What is this? 72 million, billion, trillion. Quadrillion? Is that actually true? Did you just make that up? No, it's true. Okay. We'll take your word for it for now. So in 1998 the EFF the Electronic Freedom Frontier so they built, I believe, a hardware based DES cracker for about $250,000 and they broke a key in two days. That's a pretty good number point. And then it's been getting more and more easier to break DES. So now this group, I believe in Germany built this machine in 2009. They used 120 FPGAs so for only $10,000 was able to break DES. And so this idea, this one I mentioned earlier is that in the 1980s public researchers discovered this idea of differential cryptanalysis and basically a way in statistics to understand what bits, I believe, of the key affect what bits in the cipher text from the plain text. And so if it's not fully distributed you can break things this way. And this is what I mentioned earlier that our initial version of DES was vulnerable to differential cryptanalysis but the NSA actually helped them tweak it so it was withdrawn as a standard and so then what do you do? So this initial version was just prepared by IBM submitted for standardization so it's clear that the writing is on the wall even around this time and even before you get to the point where you can build a machine that cracks it in two days you can see that computers are getting so fast that it's within the realm of possibility to break a DES. No more encryption. No more encryption? You outlaw encryption? It's a whole other issue I'm going to do. You can increase the key size? You could maybe increase the key size but the algorithm is actually really tied into the key size so you have to have some way to I don't know, do that and then what if you introduce a new problem so maybe your key size is larger but you tweak DES in such a way that now it's weakened to these new types of cryptanalysis.  You have a contest and you say let's so this led to the introduction of the advanced encryption standard AES and the whole idea was they held a contest and they said cryptographers design your best algorithms then multiple groups propose algorithms and then they held a break basically like a breaking contest and said okay now everyone analyze these algorithms and let's see which one is the best out of all of them. So it's standardized in 2001 and so you can see it was like a five year process that involved 15 different competing designs it has an 128 bit block size so why is having a larger block size important? Maybe you can have a larger key it kind of depends on the key size maybe, yeah that would make sense like the key size needs to be roughly equivalent to the block size also you can encrypt more stuff like less operations maybe especially as these chips move so like the especially if you're doing CBC what's your limit on how like what can you do can you do this step before this step? No you have to do it sequentially right so you're actually limited bandwidth wise by the size of the block size and how fast this encryption algorithm is so you can go faster if you can ingest more at once the next thing about AES you actually get to choose a different key size from 128 bit 192 all the way up to 256 bit keys so and then of course this is again and remember this came kind of the standardization effort came from the government and the whole idea of DES was to encrypt unclassified documents so interesting thing to note here like the design and strength of all key lengths 128, 192, 256 are sufficient to protect classified information up to the secret level top secret information will require the use of either the 192 or 256 key oh and this is a super interesting thing the implementation of AES and products intended to protect national security systems and our information must be reviewed and served by Bay and SA, oh that makes sense cool so basically saying like if a government system is going to use AES to encrypt secret or top secret data they are going to review that implementation which again shows you the problems that can come up between the algorithm itself and the actual implementation cool, super interesting so Intel at a certain point extended the x86 architecture there's now an AES instruction so why is that important to do it quickly on the chip in hardware you can do a software thing or you can have the chip do the AES instruction itself in a lot less time because it can optimize it it can do things in parallel cool so we are not going to get into AES you can think of it very similar to DES it's just a different box but it still has the same fundamental property blocks of 128 key size of one of these 128, 192, 256 and use it in either ECB or CBC mode a few other ways but we won't go into those at all and again it has complicated it's all just transpositions and replacements just like we saw but I don't know very complicated it's probably a good description of it so we are going to talk about something really quickly and we are going to think about so what if I sent you you stole a message from me it said it actually doesn't matter and you know that this is a so if this is a Caesar cipher what can you do if you know it's a Caesar cipher brute force you try all possibilities shift it try to see if this matches up to any word what if I told you it was a visionary cipher with a key length 4 brute force it so what are you going to get so you can brute force it you can brute force a fork yeah it's pretty easy yeah so brute force it you can choose a key and make it anywhere you want you can choose a key and make it anywhere you want so I can make it say Adam I can make it say I'm running out of four letter words you can make it your favorite four letter word whatever you want it to say and why the question is why why can you make it any possible word you want let's go back the key size is the same as the message so every single letter the key size is the same as the message which means every letter independently has been shifted and there's no relationship between any of the letters movements so there's no way you can't do any there's no statistical assuming the key is relatively random or the key is random there's no correlation there and if you're brute forcing this which of the four letter words it is so we need more information about the intent of the message maybe maybe you have that fundamentally though even making all the assumptions we've already made that it's in English that it's likely a word you still can't break this key because there's a number of key possibilities is the number of not only four letter words but two letter words or three letter words and one letter words that make sense and how you know from that universe of possibilities which one it is you fundamentally won't this is why this is a fun game I should have bet you that you couldn't guess the key because whatever word you say I'll just say the key is something else you'll never win this game so this is kind of nice though so why don't I one letter message and the cork idea was so if you knew that the key length was four but there were eight characters could you do something and what about 16 but what if the number of characters in the message is eight but the key length is eight same problem right you still can't brute force that or learn what the plaintext is this seems great did we just solve cryptography why not I'm perfect though I do agree now we need a new key for every we don't have a new key for every message we send then we're vulnerable if we have an attack of that as all the psychotexts right so now if you had another if you stole another plaintext with the same four digit key and it was whatever something you could then X or shift find out what the shift between those are do something to figure out the key maybe that could give you then you'd see what shifts in here and what keys in here are four letter words are likely right so reuse of the key becomes a problem what if I want to send in a hundred character message I need to somehow communicate in a hundred character key securely securely so that nobody else can see it but if I can do that then I can actually use this and so this is a going off of those ideas is the idea behind a one-time pad where the idea is if you can use a key that's the same length as your message you can actually use a vision air cipher or just the X or cipher that we're using and you have a hundred percent provably secure communication message for as long as you have that key but yeah exactly then you have this problem where well you have to tell the message and you have to make sure you never reuse that same key what other things do you have to do in order to do this correctly so you have the initial problem of man if I have to if I have to use a key that's the same size of the message why don't I just send them the message over that same channel that I'm transmitting the key what are some other things this could be nice though there should be a pattern with the keys the key needs to be completely random it can't have a pattern it can't just be Q W E R T Y that'd be bad but what if I was able to give you a gigabyte of a key and then I could just send you messages using that key so I can send you up to a gigabyte of data but at that point we need to start over and I need to give you a new key cool so it seems like this is like a easy just academic scheme because this is something that academics love it's provably secure you can prove the security here of this communication thing so is this never used it's just completely in the realm of yeah so it's actually used a lot in all types of military and spy intelligence gathering operations and then they would actually do like code books like entire books of literal just random characters and so then they would make two copies of this they'd send one out and that way they could communicate securely but yeah it's a huge pain right so you'd only use this for the utmost and then of course then if somebody steals that code book or that key book you're hosed right so you have to make sure that remains secret and that's difficult does that have a question for the previous slide is it possible to have a key larger than the 4x size you have the 128 and 4x size you have the 128 and the 22 no so for AES you have to I mean you have to follow these parameters because that's the only thing it's been studied under so for AES you'd have to use a 128 bit block size but you can use a 256 bit key I don't know how it works internally to do that you'd have to look that up but it does work anyway so one-time pads super cool actually used but a huge pain to effectively implement so what are some of the main drawbacks of the crypto systems that we've seen yeah the same key why is that a problem that seems awesome you know a way to securely transmit that key so can you conduct so think about you want to go buy something from a company on the internet how does that happen like what are the mechanics there can you exchange a key so using symmetric encryption you've never been to this place before you have your laptop it's transmitting over some hops to them any of those routers on any of those hops can see your transmission if you're on a public wi-fi that doesn't have a password anybody can see the transmissions that you're making they type in your credit card number it's going to send that credit card information or even worse it would send a key across and then they would use that to encrypt communication with you but if you're sending the key across on that same channel that you're talking to them what's the point right so symmetric cryptography really can only be used if you can establish a relationship with somebody and transmit a key in out of band manner but there's often a lot of times where we want to talk to somebody securely usually on computers over the internet but we've never talked to them before there's no way for us to establish a key with them and it really becomes kind of a chicken and egg thing as we've just been keep going back to because in order to securely communicate you have to transfer a key securely if you can transfer a key securely why can't you just communicate securely that way and so this is the main problem luckily math comes to the rescue a development of what we're going to call and talk about asymmetric cryptosystems or a different thing so the idea is and this is kind of an insane idea when you think about it because it makes sense intuitively the idea of keys makes a lot of sense because we have locks, we have doors you have the key, you can get into the door and the idea was and this is what people and cryptographers mathematicians, computer scientists were struggling with is how can you encrypt information without requiring a secure shared secret key it seems crazy, it seems like I don't know, it seems impossible it's crazy, I still part of why I like teaching this it's crazy that any of this actually works and they're actually able to do this and the whole idea is essentially at a high level thinking about rather than having one key that's essentially the master key you, every party basically has two different keys a public key and a private key so Alice and Bob have public keys and Alice and Bob have secret keys as the name implies who should you tell about your public key? everyone, the public who should you tell about your secret key? no one, absolutely no one only you should know about the secret key what about Bob? should Bob know Alice's secret key? no, very different than symmetric crypto you had to share a key with them but here everyone has their own secret keys and their own public keys and another way and actually the main way, I like the term symmetric crypto systems and that will be clear in a second it contrasts with the symmetric crypto systems but a public key crypto or public key cryptography is the main way of discussing this so the whole idea is we're going to start with an exercise not that kind of exercise okay it's going to require a bit of visualization and it doesn't translate super well into there we're going to assume that we have a box we'll use this box it's a super awesome super awesome box but it has a key like you haven't seen before it's got a key so most keys are lock unlock this has three different states we'll talk about what they mean in a second achieve a little bit okay, they do have the sides are going to be locked and the top is going to be unlocked makes sense so when the lock is in the unlock position the box is open anybody can open it and the box has two things so let's say I have two keys but these are very special keys that you're not used to I have two very special keys one is a key that will only move the lock to the right does right make sense here that's going to be clockwise counterclockwise but it's only a half circle so I think we're okay with right and left does this actually work? yes okay, perfect, I've got to make sure it works with where I'm doing it in here so the right key only moves the lock to the right can the right key ever so if the lock is in the far right most locked position can I use the right key to move it to the left to unlock it no, absolutely not these are special keys cool, and my left key can only move it to the left so let's say for the sake of argument that I am going to keep my left key entirely 100% to myself none of you have access to this key but I'm going to make a copy of this right key for everyone in this room okay so let's think about this I put a secret message in this box and I put it in the unlock state and I put it in the middle of this room and then I walk away and none of you see any of this so you come in, you see Adam's special box on the table, who wrote that note I just told you, come on now maybe somebody stole the box from me it was unlocked and put it here and wrote a message and put it in there the lock is in the unlock state the box is in the unlock state there's a note in it yeah okay, let's think about this yeah, so let's go out of this so the box is in here, who wants to be the first person to walk in the room what's your name? Joe Joe walks in the room, he sees the box there so what are you thinking that you know about the box and the note contents in that box you think it's likely but it could be mine, could not be mine you don't know, you sit down who's the second person that comes in yeah, so you come in, what's your name? Josh, Josh comes in he looks at the box, he looks at Joe he looks at the note what do you think about that? yeah, who's to say he didn't take the note out and write his own note and put it back in or it could have come from me or it could have come from somebody else and the third person can do that and the last person in here has no idea of what's in this box because at any point anyone could have changed and edited that lock everyone agree with that logic? so I'll agree when this box is unlocked nobody knows what's in there okay, let's say I wanted to write a note and this is breaking down a little bit but that's okay so I want to write a note we'll go with poor Josh because he didn't know who was doing and messing with these notes so now I want to write a message that says let's say class is canceled everyone gets extra credit into the box and I want you to know that I'm the only person that wrote that that message so what do I do? so I pick the box that's in an unlock state what do I do with that box? lock it? there's nothing in the box I write the note and then what? I put the note in the box and I turn it with my key so currently the lock is in an unlock state I turn it to the left and then I put the box in the room right? so now you all get here let's say you all wait for each other you're all here in the room is there anybody that you trust? well I guess it actually doesn't matter you all have identical copies of this right key so how can you prove to yourselves and each other that I was the one who wrote that note so you know that it's because it's in the left position? the only key that could have put the lock in the left position is my key can any of your keys do that? your key only moves the box to the right so then how do you read the note? you turn the right key you turn it to a mocked and at that moment you know 100% I wrote that note or you know more technically the person who has this left key wrote that note and then you can read that message let's say one of you, I won't go with a dark example wants to the box is on the table in an unlock state you want to write me and only me a note that says one of your classmates deserves extra credit because they're super awesome and they helped you to study for the exam or whatever so you write up this note how can you do that in such a way that I know that nobody else can see that note lock it to the right lock it to the right so you take the note put it in the box you lock the box to the right but now can any of you open that box? even though you have the same key none of you can open that box because it's always in the far right position and you can't possibly turn that box anymore so when I can take that box turn it one quarter back to unlock to open it up and now I know that do I know who wrote the note? no but I know what I know it's one of you or anybody that had this and I knew it was only meant for me and I know that the only people who have seen that note well I know that nobody was able to tamper with that note let's say that because I know nobody else was able to open this box unless that but I would, well exactly that's their problem but even if somebody tampered with it I know once they put it in and locked it that nobody else was able to mess with that box or change the contents of that box cool so this is public private key cryptography that we just figured out very easily at a high level it is incredibly cold but the concepts here are fairly clear in that this left key is my private key this right key is my public key and basically I can encrypt something with my private key such that any of you can check it that it was encrypted with my private key with my public key but you can't forge something with my private key and vice versa the other, yeah if you wanted to like keep something private to yourself could you put something in there and lock it with the public key yes, if I wanted to keep something for me that only I could unlock because I have a copy of my right key I could put it in the box and move it to the right and then none of you can undo that unless me with my secret key in this example, no right we don't know that but we can examine the box as stated and the other important thing is there really any difference between this right and this left key what if I swapped it around and said I'm going to give you all my left key but my right key I'm going to keep for myself it would just switch the states it would just switch the states but fundamentally everything still remains the same right, I can still put a message in that box such that you know it actually came for me and you can put a message to me that nobody else can mess with and these are the fundamental properties so even though we're going to use this kind of terminology of public key and secret key in most almost all crypto systems they're essentially can be interchangeable which is nice because they're not special they're special in what you do with them the public key you give to everybody make sure everybody knows it and has it you always keep secrets I guess sacred if that's also your thing cool okay so this actually and actually I stole this from somebody online this analogy that I really like so you can go check out the full blog post if you feel like you want more explanations here but I think this has a really good analogy for the idea of having separate keys doing different things and that allows you to build a crypto system such that now even if I don't know you as long as you have my public key you can send me a message and I know that nobody else mess with it right from what we got we got super cool security properties we got confidentiality how do we get that so what aspects of confidentiality do we get so okay so so going back to the analogy if I put a note in there encrypt and with my secret key and I put the box in there what does that mean right so it doesn't give me confidentiality because anyone with my public key can read that message so there's actually no confidentiality gained there because my public key lets assume everybody in the entire world has a copy of my public key but what did we get confidentiality from if someone locks it with the public key then only you can open it with your private key exactly so if you wanted to send a private message to me that nobody else could read you would put it in the box, encrypt it with my public key and now even if you use the public key you cannot read that message you cannot open the box except with the private key which is the one that can open that box and read the message so we get two cool properties and hopefully you can see that if we all have public private keys and now we get to move away from the boxes it's very confusing if you have too many boxes around but if we all have public private keys if I want to send you a message I take your private key your public key encrypt a message send it to you and if you want to reply back to me you can take my public key encrypt a message and send it back to me so is there like example you just gave you kind of said like your public key and my public key so there's like two sets of public keys in that sense or is it just that everything so every entity will have a public and private key the private key they never share with anyone the public key they share with everyone exactly cool we also how do we get non-repudiation what does that mean let me refresh our memory it's been a while it's a big word you can't say you didn't send it right so for me sending a message if I so if I want to send a message to somebody or let's say everyone how can I make sure that nobody else can read it or that I can't claim that I didn't send that you can all see that I'm the one who put that in there nobody else could have possibly put a message in there right cool okay and and maybe what should be this is actually kind of a it's a weird intuitively obvious thing that has crazy ramifications but if I'm giving you all my public key what should be true about that versus my secret key they shouldn't be the same for sure definitely yeah one for the other yeah you can't derive one from the other so you shouldn't be able to take my public key and be like oh here's Adam's secret key that would be bad from the shape of the key how to make the key move the other way that would be very bad because now the fact that I'm the only one who knows that secret key is no longer true equals sq or p not equal to mp and if p equals mp do you think we should be taking steps to like find alternatives to public secret key encryption in case it is proven so a lot of things in there in general I know the like RSA style security which deal with factoring numbers is not resistant to quantum cryptography so I know in that sense they've already moved on to like types of public private key crypto that are resistant to quantum cryptography so in that sense I think we sidestep it I don't know I think my money is kind of on a p is equal to np but we can't ever calculate it really well like it's going to be some kind of thing that doesn't actually help us yes exactly like it'll have some crazy high constant or I don't know something but that's my completely uneducated guess so don't quote me on that okay so this is actually pretty easy requirements that we've derived just from talking about this in class so it should be yeah so how do you know cool so great so think about this that situation right I get to the box I see that there's a message for me how will I know there's a message for me it's locked to the right it's locked to the right which means nobody has mess with that message since it went in the box so I unlock it I look at the message how do I know who wrote that message you can put this name on the message they can put their name do you guys lie and put wrong names on things all the time I mean now you personally I don't lock where each of our keys turned it in a different direction yeah or it gets more complicated but we'll get to that in a second so you need to think and we'll see that we can actually use these two properties to build systems that allows to do that the way to think about that is if I have your key that turns your lock your public key you could get a box unlock it put your note in there put yours to the left then put that box in my box put that to the right with my public one and then I could open it up see oh this is just for me it's not been tampered with and I take your box out and I see this is your key unlock it with your public key so I know that you're the one who put that note in so yes you can get that we'll go over it again this gets a little crazy but again these are basic building blocks and it just makes us that you just have to keep in mind who has what and what does that mean so and the important thing to know is that everybody knows everybody's public key including the adversary who's trying to snoop on this conversation cool okay so we'll use this notation going forward of a message so Alice uses Bob's public key to encrypt a message to get some ciphertext Alice sends this ciphertext Bob can so okay we'll go back so then how does Bob read the message and go backwards Bob uses secret key and you can think about encryption I mean it's it's really we'll just talk about it like this I mean encryption decryption it's essentially the same thing here so Bob then uses his secret key to then transform c back into m and to see the message and so now it's worth thinking about at this point what does Bob know is true about this message it was meant for Bob does Bob know that Alice sent it does Bob know that Eve sent it no knows nothing except that at this point Bob is 100% certain that the message was meant for him and has not been tampered with since that message was created so we'll stop here and we'll continue on the public key crypto


Welcome to Toffy TV, it's the Everton News Daily. John Joe Kenny is unlikely to remain at Schalke if Everton wants to sell the player to the German side. David Wagner has been speaking today and said they simply don't have the financial power to buy the young Everton right back at the moment. He said a lot of clubs still unsure about what money, if any, they will have this summit and we are no different. They want to extend Kenny's loan at Gelsenkirchen for another 12 months. He's done brilliantly, he's a great lad, scored a goal, had assists and the fans really like him and we want to do everything we can to keep him here on a loan basis. He said but if Everton are looking to sell a player then we simply won't be able to compete in the market. It's going to be an interesting decision for the 23 year old to make because obviously depending on what Everton have to spend in the summit, if anything, this summit then Kenny may find himself in with an opportunity to outshame us Coleman. There's an option in place to buy him for around £12.5m if Everton choose not to exercise that option and he retains the Monaco then it means that the only recognised right back we've got really will be shaming Coleman. So it means Kenny would have an opportunity to make it his own but it just depends whether Everton think that he's good enough to do that, he's been good for Schalke this season. So an interesting few months I have for John Joe Kenny that's for sure. Apparently Everton bid £15m for Brazilian winger Gabriel Varon after the under 17 well cup last year. Hogei Nicola in Brazil has said that Everton lead the race for the young wire player. Arsenal also very interested in him but Palmeiras wanted more than the £15m that Everton offered and this because they only owned 60% of the players rights. 40% are still owned by Santa Cruz's previous club which means that obviously they would get 40% of any transfer fee. What can you say? Everton obviously looking in this market. Marcel Brand has made that perfectly clear when he come in that this was a market Everton would be looking in and looking at players we've been linked with a couple of ardenting young players and obviously a couple of the Brazilians, Renier, Jesusby and one that Everton almost had before Real Madrid took him so this one. There could be something in this but certainly not of those figures and not for an unproven young Brazilian we wouldn't be paying anywhere near that amount of money. Yannach Balasi has had his lone move under the sport in Lisbon that according to a bowler, the Portuguese newspaper. They've said that the league is looking as though it may not return and they've told Balasi is no longer needed in sport and he will return to training with Everton once it is safe to do so. Obviously Balasi is still with a year left on his Everton contract. He signed for a five-year deal in 2016, one of Steve Walsham, Ronald Cuman's first signings and he'll be back at USM Finch Farm and maybe Carlo Ancelotti will have a look at him and assess from there because he's our player, what do you do with him? He might become a member of Ancelotti's squad or somebody else might come in and take him. Obviously Christopher Palace linked with him heavily a lot lately as well so we'll have to wait and see. Andre Gomez beat Rhys James 8-0 today in the FIFA Invitational Cup in esports. He was very modest after it and revealed that he only actually picked up a PS4 a week ago and had the game of FIFA. He said that after training he doesn't get involved in playing FIFA like the other players. I don't know whether he's being a little bit of a shark there and winding us up but he destroyed Rhys James 8-0 and people watching have now tipped him as one of the favourites so maybe Everton will get some silverware after all. Sky and Beat here in talks with the Premier League about screening Premier League games on the free-to-air channels. This is to ensure that the social distance and measures that are in place remain and will remain for the foreseeable future. There's some talks today and some statements today that there may not be any social gatherings of any note for the rest of this year which means we won't be back in stadiums as football supporters until 2021 because obviously they're just only now getting on to testing vaccines for COVID-19 and that takes time to roll out and everything else so people will be asked to socially distance. We're still currently on lockdown and probably going lockdown again when this one's up but there'll be a phased return that month of social distance and measures. In fact, they've said today that even people as young as 50, 50-year-olds should be staying in now as well. 50-69-year-old brackets have to be careful as well. The initial warnings were for over 70s but they've now dropped that down to the 50-69-year-old brackets so they're really making sure that the social distance and measures remain in place as we try to flatten the curve of this pandemic. What will happen is the games will return and they'll be behind closed doors and I should imagine now that they'll all be available on free-to-air channels as well for everybody to watch. That is it for the news daily. Make sure you subscribe, give the video a thumbs up and if you want more videos join us on Patreon. See you later.