Hello, my name is Martin de Guilamas from Moodle. Good morning. Good afternoon. Good evening to everybody I've got a little bit of time here to tell you what's going on in in my head in my world and Be happy to talk to you afterwards Wherever that's possible on the conference site. Thanks very much to next cloud for inviting me to speak Real pleasure to do so and I'll share the screen now and show you a few things while I'm talking So, look, I really want to talk about Moodle cloud Moodle, sorry our next cloud together and particularly The things we share and the values about why openness is in education is essential Talk a bit about Moodle first Bit of a catch-up some overview of what we're doing Then I want to talk about the Moodle and next cloud integration work That's been happening and continues to happen and then I want to really dive into the big issues of the future So the last year of course this year has been An incredible one in the education field with at the peak. We had nearly 92% of all learners in the world Having to study online suddenly or being at least taken out of school and As a result has been all kinds of upheaval and education and a lot of decisions being made and a lot of changes being done and It's been a crazy crazy year if you're in the field We are in education technology Current stats of Moodle LMS in the world are installed. We have a hundred and sixty thousand Registered sites. These are ones who just press the registration button. Of course being open source We don't really know all the installations and it's a good deal higher than that But still if you look at the statistics, there's 30 million courses on those sites and you know, it's a significant Proportion of the world those numbers jumped from In February there was a hundred thousand sites registered and it went up to a hundred and sixty thousand sites since then So you can get an idea of the kind of growth. There's been in 2020 with people wanting to go online And the Moodle world though, it's not just our LMS. We also have another LMS for workplace It's based on that one and it has extras. I'll cover that briefly. We have apps to access these platforms And these are the tools that we make we also have things resources that we provide or organize so the Moodle partners are our Network of service providers around the world. We have Moodle cloud, which is a SaaS platform Mostly for smaller sites. We have Moodle net, which is a new social network. I'll talk a little bit about that And we have development partners of all kinds that that we work with including next cloud In the skills side of things we have a educator certification And I'll cover a little bit of that and we have Moodle moots their conferences that run in different places all around the world they've all gone online and We're actually Restructuring them because we probably will always stay online from now on Like many other things even after the virus is sold Globally Moodle's got a very high penetration I mentioned some raw numbers but in the higher education space this is what it looks like for learning management systems and you could see in some continents each one of these is a continent that Can go up to 80 odd percent The place where Moodle is faces most competition really is in the US in North America Where there are large proprietary LMS's that we that we Compete with although we don't really look at it like that because we're the only open source one and we We're doing our thing and we're doing it for however many people are in our community So we operate on a different level from a proprietary company. I will talk about that as later as well But overall it's about two-thirds of the world's universities and higher education use Moodle in some way So the big thing that we are focused on here in the Moodle community is a big focus on UX user experience Moodle has been around for 20 years or so. It's an old code base it comes from before social media existed that gives you an idea and there's a lot of UX that That needs to be updated for the modern world and we've been doing it slowly slowly on our six-monthly releases but we are focused on spending an extra whole year to really do some big changes and There will be a couple of very small six-monthly releases happening in November and next May But by the end of next year we have 4.0. It's a good time to to really express that UX focus So we have a number of really large projects. We're overhauling all the navigation across the system Search and menus We're focusing on the process of creating a course so that teachers have clearer and better support around creating courses and hopefully with higher quality We're focused on the student experience how they know where they are how they know what they've done what they still have to do And we're fitting all these together with a new design system and that includes a component library, but also Just a new philosophy for how we fit those together There's also a whole ton of little small what we call low-hanging fruit Little obvious things in UX that we know we need to fix and we're tackling a lot of those as well The Moodle community is not just the the core LMS though. We have 1730 plugins and climbing these plugins extend Moodle with extra functionality You can see a couple of the most recent updates here from the front page of our plugins database and we have a very Interesting new approach here in that we are keeping although all those are GPL by the way, and they will always remain GPL it's required to be part of our plugins database that you have plugins that are under open source license and particularly GPL but Many of our users can't install those plugins and have the value of them because They need to get their university admin or IT person to install that code and they may be Wary of doing so they might not trust it or they don't want to maintain it and and so Some of the the benefits of this open-source project don't get to the end users So what we're building is a plug-in service and we're turning basically all of those those apps into an app store and we'll be serving them up Through the LTI standard so that they look like they're part of your Moodle site But actually they're running somewhere else on a cloud And so that will be a subscription service and that means even teachers can install plugins From a an app store without needing admin approval Well, you know the admin probably still has to allow them to do that but It won't affect the installation or anything else they're worried about The the other LMS we have Moodle workplace, which is as I said Moodle plus these extra features focused on the workplace Multitenancy and organization hierarchy and so on This is available through our partners only but these features are all coming into the main Moodle core LMS as Well, but over time so the next thing in Moodle 4 will be the report builder that's going to be landing From workplace and that's a really fantastic thing that allows you to build reports using a graphical interface very very common need in the Moodle community And here's a big glimpse of what Moodle workplace looks like it's very popular. It's going very well some huge projects are using workplace Such as network rail or the rail system for the UK Military all sorts of things quite interesting applications for workplace Another one of our projects is Moodle net and it's been going for a while as a kind of a skunkworks project. We've had We're building a social media platform for educators and the primary goal of that is for educators to find Others like themselves who are teaching the same subject and and to share resources and to collaboratively curate the best resources for teaching that subject in that language at that level So this will be released Tomorrow actually the first beta 1.0 beta Moodle net and It's simple at this point is still being still early stages But the most exciting thing about it is it's built as a distributed federated system. So there's not just one site there's many and there will be many and It's a big experiment, but we have some good hopes for it It's really something that's missing in the education world today is a decent system for curating the open education resources that are around And last little project I want to tell you about from Moodle is that we have a Moodle educator certification program This isn't just for certifying how you can use Moodle. This is Moodle's program for certifying that you are an educator And that includes 22 competencies that come from the European Union And it's called Digi comp They include, you know professional engagements and how you manage digital resources and Assessments and teaching and learning these are kind of Moodle things But also, you know how you facilitate your learners digital competence and in the power of them and so on So we have a this detailed certification which anyone can take come to Moodle It doesn't teach you how do you do these things? It just certifies of them So you need to be a pretty good teacher to take this certification It's not a couple of hours. This takes weeks but you do get at the end a very nice certificate and Hopefully it's really worth something to you because it's it's about 200 euros to get the certification and It is as I said a quite high quality and deep certification So let's talk about next cloud and Moodle in the education space I'm a big supporter of next cloud. I'm Huge fan of privacy and open source as you might imagine and I I love that next cloud really tackling the space that it is and I Fully supported doing what I can from my end to help support that and part of that is to get our integrations Better and better So the first round of integrations that we did was from December 2018 Most of this work was done by some community members Moodle community members who were also using next cloud in the University of Munster We have so firstly and these were brought into call for our team and then our standard features that next cloud can be a Repository inside Moodle, which means you can say whenever you want to add a file or use a file You can say yep get it from my next cloud installation Moodle also will use next cloud as an OAuth 2.0 Authentication source so you can log into Moodle using your next cloud account And so in these ways, it's very similar to our Google and our Microsoft Office integrations We wanted to have next cloud in there as an equal An equal member of those, you know, like with the same sort of functionality So there was an open source alternative But we want to take that further and further now and make next cloud the best integration for this sort of functionality So phase two and by the way the colors I'm using here indicate really who's who's been doing the work So these are blue because this has been done mostly by the next cloud team With a bit of support from our team so the Moodle app now can also authenticate from the next cloud site and So when you're logging into our Moodle app if there's a next cloud SSO set up you get sent to the next card site Everything works perfectly The next cloud dashboard widget there's a new one and it shows upcoming Moodle events and Recently access courses from the Moodle site that's connected And lastly, there is a search integration so that when you're in the next cloud search You can find Moodle stuff and here's a bit of a couple of screenshots showing that work that's been done lately Here's the notifications on the dashboard and Here's the search in operation. So there's a couple of really good steps forward That is not nearly enough So we're starting work on phase three and we're deciding on the features I'm going to tell you some of the things that are on the list that are still being discussed and prioritized And this is where if you're interested in this whole thing You can actually start getting involved and helping us decide what it is and also hopefully help us build this stuff So the first thing we can do is we could synchronize Moodle groups with the next cloud circles That will be very handy in the documents for example that are only available to a particular course in Moodle That only those people enrolled in the course can access that document things like that We can also be synchronizing the calendars between Moodle and next cloud pretty obvious one I'm sure there are hacky ways to do it now by iCal and things like that But it would be nice if it was just kind of automatic when you connected them one Moodle with the next cloud There's a task manager in next cloud. It would be great if we could see Moodle tasks appearing in there So perhaps, you know assignments that adieu appear as tasks to be managed in next cloud And and overall just more smoother transparent single sign-on We shouldn't always be having to log on individually to lots of systems that the more we can make it Seen like one system. I think the better Particularly when you're thinking about a school or a university in the education environment The more transparent we can all make it together and seamless the better. So it's something to research a Big one for me is to make it easier for a teacher on in the Moodle side to embed a document from next cloud as content and have a very clear decision to say is This something that's collaborative or not Is this content? I as the teacher and putting into the course for students just to read or is this something that I want everyone to work on together And we want to make the whole UX around that and other things a lot simpler It is kind of possible to do it now, but it's not easy to discover or set up Basically all the UX on the Moodle side there is a lot of little things we can do to make it easier and more Transparent and it might include some next cloud work to get that slickness But if managing documents in Moodle, but keeping them in next cloud Can be done smoothly. I think we have a real winner here for the open-source proposition I think we we could also be showing next cloud in the Moodle dashboard which has its own blocks and Payings So we could show recent files in there and notifications coming from the next cloud end as well There's obviously work to do on what that UX looks like, but I think that's a promising area of development The last one I see is a possibility and this might be mostly on the next cloud side is At the top of next cloud where there are all these the icons the plugins I forget actually what next cloud calls and they're not plugins, but those those features I think there's room for a Moodle icon to appear in there to be very explicitly have a drop-down or access to a dashboard To show what's happening on the Moodle world So it could show at the simplest even just a list of all the courses you're in to make it easy to jump to them But it could also show Moodle's dashboard in there as well. It's a possibility. So some way that could be done there If you're interested in joining in on this phase, there's no timelines on it yet We're committing as much resources as we can but we would love the communities on both sides to who are interested to engage With us help us drive this forward The place to go I've set up a Moodle tracker issue for it This could easily be one on the next cloud side as well But if you go to Moodle.me slash next cloud that will take you to the tracker issue and you can Subscribe to that issue and start putting comments and you know just express your interest I think just to get everybody together and talk about what we need to do So that's it for the next cloud Moodle integrations interesting work there and I I love Next cloud. I really want Moodle to work better with it and you know Committed to with Frank from the XFAD site to for our teams to be working together on that and making it a better and better thing But let's talk about the future And I'm a wider scale that's a global scale and the kind of environment that we're in and why are we building these things? And what should we be building is is an important question the UN Some years ago came up with the 17 sustainable development goals these are basically the most pressing problems that the earth is facing right now and You can see a lot of hot button topics there obviously climate action and Equality of many kinds quality education and reducing poverty, etc, etc So how do we support that and I'm thinking in the education field? How does education support that but how can we all be supporting that and what? What are some of the issues? So here's some Issues that are just to zoom in a bit a little bit more detailed about some of the things that we're facing some of the bigger problems Under that that we we need to be looking at so one of them is that The whole pandemic has really forced a lot of people to evaluate and reevaluate what being remote means What it what it means to not all work together in the room This was a trend happening anyway, and I feel it's time that we have good systems to work together and learn and Do all the things we need to do online Now that comes very core to where do we do that? Where are the spaces for working and and educating and doing all these things and who runs them? It starts getting more and more important when we Putting our private information and our data and our lives effectively Into a system as to what's going to happen with that information That's another big trend of artificial intelligence versus human work Don't know if you've seen some of the I've been following it for decades But in in the last year the advances and AI have been quite exponential There is one particular called GPT 3 which comes from an open AI. It's been trained on billions of documents This AI is a general AI that you can put onto Problems that we previously thought were only that only humans can do and it can do them easily It's not and I it not an intelligence as such But it's just a statistical engine that given a word or a situation Finds the next word to put in and the next word and the next word But for example people are using it for applications like, you know describe an app to it and it will create the app and the code to make that run or Give it a sentence and say write me an article or a book and it will complete the article and the book and Actually, it's a pretty easy read now it may have factual errors because It doesn't know anything about what's true or not true but it will write things like a human would write them and make you know, you could easily make a system to say Create a new Wikipedia from scratch, you know, right millions of articles about everything and this AI will go and do it and A lot of people would find those articles perhaps in a search and think oh, yeah, that's truth That's an article written by somebody. In fact, it's all just being generated by this machine so When we have AI of that level taking away human jobs, what does it mean to be educated? How do we? Operate in this new environment where machines are generating more and more of the information that we have How do we know? How do we separate? And we come down there also like formal education and inform education. I'm a big supporter of formal education I think a society should play in its education and its topics and we should be very intentional about what our next generation needs to know There is a big battle if you like between that and everything else right the internet is full of information that you can learn from and Educate yourself and it's terrific, but there are some issues people Going into You know, there's filter, but the filter bubble problem So you might learn a lot about one thing and then not very much about everything else and That leads to problems like in democracy How how can you vote for somebody or how can you participate in democracy if you know only a lot about one thing? It it's it's an issue There's also the problem of fake news as I said before so much potential for Misleading stuff and we are seeing it more strong more and more strongly all the time how social media is distorting the truth continuously Now lastly, this is a big one that I'm sure is very near and dear to anyone who's at a next cloud conference Which is the big tech versus open the centralization of technology versus Decentralization that is the issue the biggest issue that we as technologists should be fighting for the more And if we wrap all these things up if you have an education system that is built on top of centralized for-profit technology Then our education our news our information can start to be Swayed and distorted by commercial interests if those commercial interests are connected to governments or whatever You have a lot of quite scary possible scenarios. So so what do we do to keep education being the best possible thing? for society well Let's let's look at what the best future is for for tools resources and skills in in education. I Showed you this before which showed the moodle activities under tools resources and skills if we go wider the more generically Tools should be open education technology resources should be open education resources and Skills should be open recognition Now I'll talk about these in in a little bit more detail But the open education technology is pretty clear. I think it's open source It's technology that evolves because the community is driving it It doesn't have commercial interest embedded in it. It doesn't have prices that are gonna cut out huge portions of the world and It has the flexibility to evolve Resources Open education resources the last year UNESCO which is a Collection of almost every government in the world Passed a recommendation to their own members, which is every government in the world except the US To focus on open education resources, which is terrific news That means less on paying publishers to for expensive textbooks more on Building and supporting open education resources You know documents and and data that is open and under creative commons licenses and open licenses like that So that's that's well established this last one is still very new open recognition So there is something called open badges, which is a start towards this, but that's not all of the problem The problem is once you've learned something or once someone has recognized you for something How do you give that to others in a way that is That you can trust So if someone comes to me and says, oh, I know about this thing How can I be sure they do know about this thing, you know without actually testing them? and what I want is a Someone who certifies that they're good at that thing Or someone I trust and I want a trustworthy way of that being stamped so that I know So there's a lot of work happening in this field. It's very important for education, of course because they Once you've learned something you want to keep the knowledge of that and you want to store that somewhere We do not want to all be using LinkedIn First of all, you can lie all you want on LinkedIn and it'll be accepted as truth on my LinkedIn profile It says I invented LinkedIn and I did that just to show that it's very easy to lie there We want something more a better framework an infrastructure that's open that we can all trust And that's what they're building here So I'm going to focus a little bit deeper on the open ed tech because that's more related to what we'll hear about today There is an organization that I'm launching called open ed tech and Open ed tech global is the website. It's kind of new but it's it's not actually doing much itself It's really an association of companies that fit a criteria to be called open ed tech And they will be able to then have an open ed take open ed tech Certification that says that this project is fitting the principles of open education technology and some of the companies that fit under their umbrella they we haven't actually got the Certification as yet But this is to give you an idea of the kind of projects that that do fit things like H5P or Mahara Which is a portfolio system Open edX is a MOOC platform Kohara is a library system Matrix is a really interesting project about messaging So text messaging as well as audio and video I if you don't know about it, I highly advise you go look at matrix.org I would love to see next cloud be integrated with matrix Moodle net the social network I mentioned next cloud of course Edumete is a video conferencing platform Produced by G Ante G Ante is the connection of what a collection of all of the network providers in Europe Big blue button a very well known video conferencing classroom system badger Which is an open system for managing badges open badges and and moodle and so on So these are some of the projects that will be involved in some way our job is to promote the brand of open ed tech as as a brand so that people can understand that you know Yes, this project has the right idea and these ones the other ones don't It it shouldn't be about what is cheaper It shouldn't be only it shouldn't only be about where it comes from it should be About how is this software constructed? What are the principles of it? What's the sustainability of that software? Will it be around for a long time and how does it integrate with everything else? so With the tools resources skills get OET and open source open education resources and here are some other People who've been involved making that happen and then the skills badges and open recognition So let me just tell one little story one little thing that I think That that might be where the future of education is and I I want to Drop this seed in here and see what people think So you may have noticed an informal learning space especially there's a lot more a lot of Collaboration and I I'm I'm quite a big fan of what's happening on YouTube to a certain degree I don't like that it's YouTube, but I do like what I do like is that there are so many teachers there Who are all contributing to each other everyone's learning from each other? There is an easy way through algorithms and tagging and so on to find related stuff And so we have a network of people learning from each other and the same on social media You know with with all the problems of it. There's so much good stuff happening and What we're effectively doing is we are all learning together as a society but You know about politics about current news, you know We're like nodes on the network and together. We're kind of thinking like a big brain And that's happening more and more and more It's across countries. It's across any organizational structures It's just you know, the world on the internet is connecting more and more and learning from each other This is a great thing But as we would as we know you also see people Going off into these filter bubbles and you know learning how to be a great Nazi or something It's it's perfectly possible to learn everything this way. And so there's no inherent Support of the SDGs or you know the global context. It's just people learning from other people which is Just good to point out The second trend I'm seeing is this The emergence of let's say gurus, I'm gonna use the word gurus Now guru is a hingy word that means basically teacher But there's a lot of Baggager that comes with the word guru when I what I want to use it for is because I'm talking about a very high level teacher someone who's really good at what they do is able to actually produce a feed of Interesting content, you know as that teacher evolves and learn Learns they share that and they have followers who are interested in that and are following with them and there's a constant feedback loop of you know, the Followers are saying they love it. They don't love it. They further ideas and then you have You know ongoing growth everyone's growing together But there is a guru in the middle of facilitator and there's so many examples of that on the internet A really good one actually is Martin, I'm not sure of his last name, but he's building a marble machine. You may be my mark I just look up marble machine He's in the band winter garden and look at the process by which he's building the new marble machine And how his whole community are learning together through YouTube and other social media. There's many many other examples now what I think we could be doing is building a platform of Open education technology of OER and this open recognition so that a guru Can just pull off the shelf everything they need for free and I mean really for free like not with all the fine print of what YouTube is which is selling your data and Advertising and monetising on your data But a true open education platform That this a person like this can use and then that person is now empowered to to grow and teach a huge group of people Through the internet now I'm not saying this would happen outside of institutions I think every lecturer in every institution should have the same mindset that they are the guru with all these tools and they're able to create a community around themselves and If you like that teacher kind of docs They might have their own platform that they dock with the institutions platform So yeah, you enroll in some university and you now have access to that teacher who is associated with that university And you join that community. So there's possibilities here to really kind of use what works But in a new way that promotes quality that promotes Research and science and facts and of just a high quality of education to really start producing citizens for the world So in short, I just want to encourage everyone no matter where you are or what you're doing fight to keep Education technology open We need to I think if we don't there's possibilities for the very large companies to start taking over the education space And once they do that They will also take over the future of the planet and I don't think that's what everybody wants Here's some of my contact details if you want to get in touch very happy to talk with you Thank you for listening and thanks for the opportunity. Have a great conference. See ya


Bye, what's up everybody, once again it's Brandon Shawn and today we're gonna go over Does Beats by Safe have a legitimate chance to be one of the next big producers and does his method actually work. Now I was put on to Beats by Safe a few months ago in terms of I was not too long after he really started to become known and I was put on by one of you guys. I could not find the comment though, my bad if you out there appreciate it. And for those of y'all who don't know who Beats by Safe is, he is basically a producer, beatmaker whatever you want to call him but he's gotten known through Twitter by basically finding popular comments from let's just say celebrities, popular rappers and then doing tweet replies to be at the top of their threads. And I don't just mean a few of them I mean a whole lot of them to the point that people who are following them get to know him and they see this little video of him playing his music. Of course a lot of people are calling Beats by Safe a spammer and things like that and even the person who brought Beats by Safe up to me wants to know does his method work. Immediately I thought the fact that I was being asked about was his spam method working let me know in my mind that he had to be on to something but I decided to wait a few months for a video just to see what happened and here we are. So you guys might remember if you've seen my fitty while video I talked about how the fact he was hitting people real hard hitting people real hard from all angles a lot of DJs and the fact that DJ Envy actually ended up blocking Fetty Wop even though he supported him and actually advocated his push later down the road. Beats by Safe had similar events. Smoke Perp actually tweeted stop nigga please. And hey for one as I've said plenty of times your first goal is to get out of obscurity if people do not know you they can't listen to your music they can't buy your beats. Black jokingly tweeted Beats by Safe saying that one day he was gonna post some deep stuff and Beats by Safe would reply only with one of his beats as he's been doing everybody else. As a matter of fact Ugly God blocked Beats by Safe and then turned around to follow him DM him and basically apologize. Safe actually got to meet Ugly God. I'll make sure I link this video down below because it's pretty dope. Follow me on Instagram.  Hey if I get to 10K should we drop a song together? Oh and not to mention Fish is in Plains wrote an article about this troll Beats by Safe so how many people have been spending so much time trying to email blogs and get on blogs and he already had a blog written on him after about maybe a month or a month and a half of doing this but let's be clear this dude is aggressive he's so aggressive and stays on tweeting these people that a lot of people have thought that he had a bot to actually get it done. So as what he's been doing working obviously so far just from those who think yes he's gotten out of some security people know him particularly on Twitter but to even drive that point in and even make him bigger Lil Uzivert got accused of stealing a Beats by Safe beat and this is not Beats by Safe accusing Lil Uzi this is people who've known Beats by Safe and listened to his Beats after he kept posting and posting and posting and people are like yo that's one of the Beats that Beats by Safe be posting. Now at the end of the day the people were wrong the beat wasn't stolen from Safe but the fact that he has people that know him enough and have heard his beats enough to listen to somebody else's music and think they recognize it once again reinforces that he's out of obscurity.  And now we get here. Everybody looks at this spamming as people getting bothered but you have to realize there are these social norms right these boxes that people create they're not even real rules or laws like they don't post this many times where you'll seem uncool or don't hit somebody up this time this or this many times because you'll seem needy or thirsty all those social norms exist and the people who step outside of those are the ones that usually stand out and benefit not the people who necessarily say I'm a dress different because so many people are dressing different whatever that is that you can't even tell who's supposedly different anyway it's like a cool thing the only people who really stand out are the ones who act differently and a lot of times that means overcoming that small uneasiness that it might take to post some so many times or reach out to that person you already reached out to one more time two more times I got a homeboy who's like you know if I reach out to somebody they don't ever get back to me I don't want to seem thirsty man now of course and being a go in a next big-time producer safe is gonna have to actually be a good producer make good beats but let's not forget that Metro start off in a very similar way he endures up on Twitter in my space and then once he got brought in he was able to really focus on that talent continue to move so not only has he made enough of a name for himself to have copycats but he said in three months he's gotten 20 million views on Twitter seven thousand new followers and he's gained a whole bunch of what he calls to be real fans I don't think there's much else for me to say the proof is in a pudding all I can say is don't go do exactly what this guy did find your own way and creative way for you to go hard from some different angle that's it y'all know what to do hit that subscribe button


Now, since all we need to find the change or a rate of change is the values of the endpoints, we can also find this from a graph or a function. So for example, suppose an airline goes on a six-hour flight. The graph shows the height of the airplane in kilometers, t hours after it takes off. And let's find the average rate of change between the time it takes off and three hours into the flight and the average rate of change during the last hour of the flight. So we need to know where it was. It took off at t equals zero and three hours into the flight is at t equals three. And we see that at t equals zero, the plane's altitude was zero kilometers. And at t equals three, the plane's altitude was 12 kilometers. And so the rate of change is the change in quantity divided by how long the change took. Remember the change in quantity is the ending amount minus the starting amount. We ended at 12 kilometers and we started at zero kilometers. That change took three hours. And so our rate of change, 12 kilometers divided by three hours or four kilometers per hour. How about during the last hour of flight? Since the flight was six hours, the last hour of flight is the time between t equals five and t equals six hours after the plane takes off. And so we want to know the plane's height at t equals five and the plane's height at t equals six. And these are four kilometers and two kilometers. So again our rate of change is the change in quantity divided by how long the change took. The change is the ending amount minus the starting amount. And we ended at a height of two kilometers. We started at a height of four kilometers. So that gives us our difference. Minus two kilometers and the change took one hour. And so our rate of change is minus two kilometers per hour. And again, as with change amounts, we should always choose one. Either include the sign or omit the sign and include a direction. And so we might say that during the first three hours, the plane's height changed by plus three kilometers per hour. Now since this is positive, we could omit the plus sign and just say three kilometers per hour. During the last hour, the plane's height changed by minus two kilometers per hour. Or during the last hour, the plane's height decreased by two kilometers per hour, where since we used the word decreased, we omit the sign.


Before I get in this video, I just want to remind you we're on a road to 133,000 subscribers and then 150,000 right after that. 133 is just a special number because that's how many years Nintendo has existed. So I thought it'd be neat if we just made that as a smaller short goal to try to hit 133. That being said, I'm also trying to become a full-time YouTuber, so I do appreciate everyone who subscribes to the channel. And beyond that, we have giveaway going on as well. Right now, for Prime Gaming Fest, we're giving away a replica Hylian Shield. We're giving away two collector's editions of Tears of the Kingdom and two Zelda Switch OLEDs as well. You can enter right now down in the pinned comment or description, winners chosen on June 11th. And by the way, you should just go to Prime Gaming Fest in general, which is happening June 8th through June 11th because there's a ton of giveaways. Lots of people are gonna get to win something, free games, free merchandise, controllers, et cetera. It's just a great time and there's a lot of entertainment value. So why not stop on by during one of our 12-hour live streams? All right, if you are tired of hearing praise for Tears of the Kingdom, then this video isn't for you. This is probably the third time I made a video on this topic as various outlets start to pick it up and get more developer quotes. But I'm just gonna be honest, I am not tired of singing the praises of Tears of the Kingdom. It is my favorite game of all time. Let's just dive into this IGN article posted a few days ago, diving into more developer quotes, developers they reached out to, reacting to this game because it is impressing everyone across the spectrum. So this is my Logan plant. It was posted on May 31st and it says, Zach Mumbach's been in video game industry for a long time. He's worked on AAA franchises such as Dead Space and Battlefield and is now working in his own studio that's already shipped one game and is hard at work on a second. But even the most hardened video game developers are stunned, delighted and just a little bit envious of the legend of Zelda, Tears of the Kingdom. Tears of the Kingdom is overwhelmingly impressive, he says. The bar is set so unbelievably high. Even for me, having worked in AAA for 17 years, I see that game and I'm jealous because they clearly got the time that they needed to make it really good. The game industry is in the middle of the watershed moment thanks to Nintendo's latest masterpiece. Tears of the Kingdom is dominating the conversation on social media as fans fall in love with its immersive exploration, complex building mechanics and interconnected systems. But developers are able to have an even deeper appreciation for the mastery on display in Tears of the Kingdom because of their own personal experiences with game development. While you or I can rightfully celebrate the game for everything we love about it, there's something more powerful about hearing praise from folks who know a little bit about what's actually going on under the hood. For instance, we've seen a handful of devs go nuts on the game's physics engine and this is something we've looked at before with William Armstrong drawing the bridge across the lava. IGN spoke with five game developers ranging from indie devs working on their first solo projects to devs with decades of AAA experience about the most mind-blowing parts of this Tears of the Kingdom and if a universally loved game like this is inspiring, deflating, or a little bit of both. So game developers share the most impressive parts of Tears of the Kingdom. When trying to pick just one element of Tears of the Kingdom that stands out, head and shoulders above the rest, our interview subjects had a hard time choosing. In fact, we got five different answers from our five different developers. From mum back, it comes down to the open world design on a five minute horse ride to his next objective. Mum back says he's constantly distracted by visual cues Nintendo has planted across every inch of Hyrule's expansive map. But somehow mum back says the sheer amount of content never becomes overwhelming because of the way the developers presented to the player. The open world is probably the best constructed open world ever. I can drop you anywhere in Tears of the Kingdom's map and you can spin your camera around and if you see a space that looks like something should be there you will be rewarded for going there every single time. And this just isn't a thing I see in other open world games or even close to it. The praise reaches a whole new level when incorporating the Tears of the Kingdom's building and physics engine into it meticulously designed open world. At EA mum back worked as a producer where he was in charge of breaking development processes down including figuring out how many people and how much time was needed for development to go smoothly. But even in that experience he says he can't begin to imagine how things work behind Nintendo's tightly shut doors. To make these vehicles work the way they work with the physics like the gliders and the fact that you can put rockets or fans on the back of the glider and then it's also understanding where I am standing on the glider at all times and constantly updating the trajectory of the glider based on my little tiny stick deflection movements. That's like a whole game to me. Go make that and you win an award for making that. And that's just a little part of this game. James from Indie Studio Natsukes is a solo dev working on Maple Forest, an indie game clearly influenced by top-down Zelda classics like A Link to the Past and Link's Awakening. Zelda is one of James' favorite series and main inspirations and he's similarly impressed by the ultra hand building mechanics. Even though he admits he was initially worried the construction kit was just a gimmick. When I first heard Nintendo was adding building to the game I kinda sweat a little and then the game came out and I was blown away James says. The building mechanics don't hurt the game at all they strengthen it. Now that the game has released it's obvious Nintendo thought carefully about Breath of the Wild's core strength, it's absolute freedom of exploration and it's rewarding player curiosity and experimentation and dove in and built what was surely an extremely time consuming and expensive physics and building system to make that core shine even brighter. It's crazy and it's amazing. In describing their favorite parts of the kingdom many developers found themselves inadvertently rediscovering their love for Breath of the Wild's open world design. Tears of the Kingdom is a meteor more fully realized version of the predecessor's core vision which makes the bones of Breath of the Wild's innovative elements even more impressive. Another indie developer, Aaron McDivitt of AeroGPX puts it another way. Calling attention to Tears of the Kingdom's deep sandbox, saying Nintendo's open world zealots are basically begging the player to interact with the world and game in whatever they want and in order to progress no two people will play the game the same way and that's beautiful. It fosters replayability, a sense of community and creativity all in one fell swoop. I do think it would be awesome if developers were more open to giving the player characters just enough capability, agency and sandbox flavor that could result in players finding unique ways of approaching problems and progression through their games. The player's ability to solve problems however or puzzles they want the player's ability to solve puzzles however they want is another feature that leads to viral moments in social media. Videos of unconventional problems help them to spark conversation from players sharing their own unique solutions to folks wondering exactly what is going on and I got to admit this guy shows a thing in this video and I did not solve this this way. He assumes this is the intended way to solve this. I don't think this is the intended way to solve this at all. At all. I think that the entire way I did this puzzle was definitely not like that but anyways. Moving forward, Eric Covington, a game designer reformer experienced at Blizzard and PlayStation is most impressed when Nintendo's having confidence to let the player do whatever they want. None of it is cheating or going against the designer's intention because it's all within the realm of what's intended. The intention was to get the player a plethora of toys and a sandbox in which to play with them. Nintendo doubled down on letting the player win however they wanted to. I can see other studios and games benefiting from letting their grip loosen on the intended solution to the puzzles and challenges they throw at players. Finally, retro studios artist Taylor Rollrig calls out how tears of the kingdom benefits greatly from building off another masterpiece. Breath of the Wild specifically, returning to the same Hyrule feels like revisiting a real world place for the first time in years. Rollrig also notes that Nintendo stepped up its game in the character department this time fleshing out the people Link interacts with on his second trip through this Hyrule. I feel like everywhere I go I'm genuinely meeting new people, new NPCs that are making the world feel like, yeah, Hyrule's coming back and what I did in the first game actually matters. People are able to rebuild and live their lives. So what should the industry take away from tears of the kingdom? In the years following Breath of the Wild, many games have tried to recapture its essence. We see more games than ever with stylized grass waving in the wind, ambient piano soundtracks and paragliders in the Wacozella success. But few games have replicated its true secret recipe, unparalleled exploration and player freedom. So I asked these developers what lessons the industry should take from tears of the kingdom and what takeaways big game companies might end up taking instead. Turning to Rollrig's point about Hyrule feeling more alive in tears of the kingdom, Mumbak thinks more games could benefit from the building off the worlds established in their predecessors rather than creating brand new worlds with each new entry. We're already starting to see this fairly often. Gotta war Ragnarok and Spider-Man 2 come to mind as two recent examples. While the Yakuza series successfully returned to the same map for over a decade, but Mumbak thinks that more developers should take note of this practice. Mumbak says he would love to have another game that takes place in Skyrim, for example, where towns, people and the environment have all gone massive shifts. Developers were torn on whether major studios will incorporate building mechanics into games following tears of the kingdom's mainstream success in that department. I hope tears of the kingdom style building is not shoehorned into games where the core design philosophy was originally not created with that in mind, Covington says. Now, for games that do have a creative sandbox building in some form or fashion, I definitely think those creative teams will be taking a hard look at how Zelda has implemented their systems and physics. But I don't think it'll be me make like a monumental splash in the industry in the way Breath of the Wild called out open world RPG designers. Mumbak says he guarantees executives of big king companies are telling their development teams that their games need building mechanics. But that doesn't mean we'll see building mechanics in all the finished products. As most dev teams will likely push back and say systems like that would take too much time and too much money to create. I don't think we'll see a bunch of people trying to make this game. I think that they'll be having conversations about it. And I think ultimately it's a unicorn.  Tears of the Kingdom was created under extremely rare near perfect conditions. For starters, Nintendo built this game with seemingly unlimited time and budget as an interview with series producer A.G. Aonuma revealed the game was delayed a year purely for polish. Nintendo switches historical sales success also meant there was no rush for Nintendo to deliver Tears of the Kingdom a second before it was ready. Plus there's the fact that the Zelda team started development with Tears of the Kingdom's engine, overworld combat, art direction and more already in place from Breath of the Wild giving them a massive head start and creating new content and systems right from the jump. Finally, the Zelda team led by Aonuma and long time director Hitamaru Fujiwayashi is filled with experienced senior developers who have been working on the franchise for many years. All of these elements came together to allow Nintendo to develop a generational game under circumstances that would be difficult for anyone including Nintendo itself. I find that lying really grossly overstated but to repeat, I don't want to be negative but even if most developers took the correct lessons from Breath of the Wild and now Tears of the Kingdom I'm not confident most of them will be able to do anything meaningful with them, James says. I don't think Zelda's design is something that can be learned or copied without incredible effort. Nintendo is just full of world-class talent working in an environment that's letting them realize their full potential. The result is a masterpiece like Tears of the Kingdom. For developers creating games at work while playing Tears of the Kingdom in their free time it can be daunting to feel like Nintendo has set the bar that's impossibly high to reach but the devs we spoke to are up to the challenge understanding that every team making games has something valuable to share with the rest of the industry. It is a big inspiration, Robert says. The Legend of Zelda series as a whole is what got me into wanting to be a game developer. So anytime I play anything Zelda it's usually some spark of inspiration and I want to have an impact on someone like Zelda has had an impact on me and if anything I can do in my game development can create a story that can be that for someone else then I'm going to be happy. And I love that last line. I don't know what is up with these articles ending with these super powerful closing lines. But man, I mean Zelda's impact on my life is it's almost immeasurable what it's done because major games have come out at very key points in my life and have done so much emotionally for me helping me deal with real life situations. It's insane to think that I got into content creation because of Zelda like this person got in the game development and here I am fast, fast forward from 1998 to all the way to today and I feel like sometimes, not all the time most of my content is just informative, opinionated stuff for you to use the past the time but every now and then we'll get someone telling me how much my content has helped them deal with situations in their life by just giving them a much needed distraction in a way that other people's content didn't maybe they just enjoyed my voice or enjoyed the way that I frame things or my opinions or just what I choose to cover and yeah, I know I see you comments down below that probably didn't get this far into the video complaining that I've made this video again for the third time.  This game means a lot to me and I think it means a lot to a lot of you as well and I hope the biggest takeaway the video game industry takes as we move beyond this absolute masterclass in video game design is that publishers realize what can happen when you not only keep a team together stop with the temporary employee contract junior employee fired after three month thing value your employees, keep teams together invest in those teams and give them the time to deliver a masterpiece. Now, I know not everyone can do that indie developers in particular don't have that luxury of an unlimited budget but when you're an EA studio when you're an Ubisoft studio when you're a take two studio when you're a studio for a mega corporation Embracer group should really allow this as well keep the teams together even if the last game they released maybe it wasn't the most profitable thing in the world keep the team together show value in your employees compensate them well and then give them the time to complete the project the way they wanna do it and you might find that tears of the kingdom is less of a rarity and can be more of a standard especially in the AAA space where I don't feel like there's any excuse other than executives pushing buddy buttons and wanting to maximize profits over worrying about delivering quality products when you can actually do both it might take more time but you can do both and reap massive benefits so here's hoping that that's the lesson the rest of the industry takes from this is just a sheer time Nintendo's willing to put in the dedication to their employees I also don't think that the line that this article gave about how maybe Nintendo's employees can't even repeat this let's just throw that in the trash come on we've seen this already with things like Super Mario Odyssey we've seen this with Fire Emblem we've seen this with let's just throw out there was another great example how about Kirby and the Forgotten Land we saw this with Luigi's Mansion 3 like Nintendo keeps developers together and then they grow together and as the teams grow the games they output get better and better and better we've seen this with Splatoon 1 going all the way to Splatoon 3 when you keep development teams together and you value the employees like they talked about oh so many of these developers are senior developers they didn't start that way they were junior developers and Nintendo just kept them that is the way what Nintendo is doing is giving you a blueprint what these companies in the West should have been doing this entire time so I hope that's the lesson they take is valuing employees valuing their mental health and compensating them fairly and then also hey giving them the actual time I'm not saying that Crunch will ever go away I'm not saying that it will I hope that it does one day but I can't guarantee that it does but what I can guarantee is that if they're allowed the budget if they're allowed the time if you keep them on and even if a project you did prior didn't sell it as well as you hoped you're gonna reap long-term benefits that's the lesson I hope all these studios pick up because that's the lesson the developers keep preaching over and over how did Nintendo give their employees time to do this how is Nintendo keeping their team together to make something like this how did they get a whole year to polish this game these systems are incredible look at what can be done if you just keep people together and make them happy thank you guys so much for tuning in and I'll catch you in the next video


for me from South Africa. Okay. Thank you. Dear Ganesha, thank you for your invitation. And as my title of my talk suggests, I'll be talking about some unified approach, which as you can see, Lindblat is a part of approach which is familiar to you. And non-termission is somehow, for some reason I didn't see much of the non-termission dynamics during this conference. So I guess I would feel that they're going to learn quantum open systems. Let me switch off my camera. All right, so term open quantum system usually refers to some quantum system, which is surrounded and interacting with background. And obviously if we're talking about standard quantum, mechanic quantum field theories, of course they try to incorporate the background into the picture. So to make the whole system plus environment to be unitary evolving. Unfortunately in many cases it's not possible because environment can be very complex. Therefore we need to have different models of environment and here comes the quantum mechanics of open systems. Obviously there are different models of them. One could select out the most popular one, such as Boson-Barth models, less known quantum chaotic models, random matrix models, et cetera. They have all of these environment models that have a problem. So such that analytical complexity, obviously many body systems. If you do numerical computations, then in both cases your time computations would be proportional to exponent to the of N for N body systems. Number three, the problem is a lack of generality because you always, you have to postulate the environment from the beginning and your results. So there is no guarantee that it will be general or anyhow universal. And number four, sometimes actually, especially for practical applications, you don't need to full measure of environment and body environment systems, but we need to introduce some sort of decal dissipation into model and see how it behaves compared to experimental data. Then you tweak your terms and then you probably gave a better idea about your environment, which is pertinent to your particular system you're working about. So it's actually, it could be useful if you try to reproduce or restore from the model to reconstruct the original nature of your environment, as well as subsystem, of course. Therefore, the reduced models are very popular where effects of environment can be encoded in the correction terms in the Hamiltonian or evolution equations for the reduced density operator, such as example would be limblet master equations to be considered later. Common features of this reuse approach is that your total Hilbert space is a product of Hilbert space for your subsystems and your environment. And then you introduce the average of the density operator over environment degrees of freedom. And that's where you arrive to the reduced density operator for gravity will are gonna be dropped as subscript F. As for your total Hamiltonian that obviously leads into two parts and you are, since you are interested in your subsystem Hamiltonian, this is the one you would be most interested in to get analytical or by any other form of it. Okay, so first example is the windblot approach where actually it turns out that dissipative effects are primary encoded, not in the Hamiltonian, but in the some additional terms of evolution equation for the reduced density operator. And one could play with some mathematics, standard textbook exercise. So windblot approach, you separate your subsystem from the background, then you impose Markov and Bourne approximations, then you impose our rotating wave approximation, alpha, color, et cetera, plus do some auxiliary simplifications. And that way you arrive at the master equations, which looks like quantum phenomenon equation with the commutator part plus dissipator part, which is in a quantum dynamical semi-group form has this form where capital A's are called windblot operators. So this is believable when you have a background or environment then it will contribute, or it will definitely contribute partially into your Hamiltonian, but most of the contribution will come through the dissipator term, which is trace less. All right, so can the windblot term account for kind of this particular phenomenon and question number two, can this term account for all Markovian kinds of backgrounds? Unfortunately, it's answered to both questions, as you know, and if you can see from this picture, so you see that windblot approach is basically subset of secular approaches and subset of Markovian and Bourne approximations. So it's only upon assuming all this chain of approximations you eventually can say that your system described in windblot, it can be described by a windblot master equation. All right, so there is a, on the other hand, there is a totally different approach which was, which became probably popular since the classical work by Feshbach in 1959, who in nuclear physics, which related non-hermitional Hamiltonians to open quantum systems. Well, non-hermitional Hamiltonian is a Hamiltonian which has both self-adjoint and pure joint parts. And Feshbach found that in principle, if you take almost, well, quite general system and if you decompose into the bipartite time, then after some algebra, so you have your subsystem like a shell model plus interacting with all kinds of scatterings, and then scatter in stable environment and your system is described by some discrete states. So eventually your subsystem will acquire additional term, which is not only a non-local, but also complex. So it also energy dependent. So which means that actually you have to develop some very new formulas to deal with such systems. And let me explain you why. Let's try to start with density-operative formulas. So we walk a little bit by analogy with the Lindblat approach. So we say that our Hamiltonian is acquired on a pure joint part, which can be written as a some Hermitian-operative times imaginary unit. You can write down, of course, by now, like we're showing a picture evolution equation for the state vector, but the problem is if you try to apply a showing equation directly to the system, then you'll have a lot of contradiction because on the left part, you have a clearly Hermitian operator. On the right part, you have a non-Hermitian. Therefore, you have to be a little bit more smart about this. So instead of dealing with Schrodinger equations, you have to switch to the density operator. It's also good because it allows inclusion of mixed states, better connections, open quantum system, et cetera. To do that, you do a standard procedure. You formulate a joint equation, and then it's reduced operator, which is product, and then multiplying and adding these two equations together, you arrive at this equation for your operator omega. And then you generalize this omega to any arbitrary density operator. All right, so what we have in this equation? We have obviously the standard front-line commutator term, where H plus is the Hermitian part of your Hamiltonian. And then we have an additional anti-commutator term, which is basically contains information about your environment. And then you see, unlike this equation, it's self-consistent here. Your omega is still Hermitian, and all the structures, it has a well-defined mathematical structure. Well, why it's not the full story? See, if you take a trace of both parts of this equation, it turns out that your trace is not conserved in time. And so because it's derivative, it would be proportional to this trace of your anti-Hermitian part. Therefore, you have some problems with probabilistic implications. So as the trace goes to zero infinity, how would you interpret it? Also you have certain problems, how to define purity. And then you have some energy, you lost your energy gauge invariance. So all these three problems say somehow make you not happy make before this reason of this non-Hermitian systems were not popular, they're not become popular immediately, although they appeared as early as the 60s. Well, apparently there is a solution to these problems. What you have to do is you introduce a personal organization. You have to introduce your operator, which is measurable, we call it measurable. And because all the averages are computed as traces for this new operator. And this is your omega or omega divided by each trace. And that way you eliminate problem number one, you can problem number two, because you can define purity in some way. The only thing that's interesting is that your equation for omega turns out gives a rise to the equation for rho. And rho has a very similar structure to the older equation. Plus this new term, which is something new, it is non-linear because it contains average of your anti-Hermitian part of your Hamiltonian over your Hilbert space of your subsystem. And for example, if it's a full X space and it's a integration over the whole configuration space, and so it's non-linear because its gamma contains also rho inside and it's non-local because it's in general contains all those integrals over the configuration space. But it's always manageable because you can always use this equation and that and go back and solve it and then go forward and check what are the physical consequences. Okay, so this is actually was something you wish somehow people haven't really think about before 2012. And since we have a Lindblot approach, the old good one, and we have also this new approach that it's also tempting to create a hybrid approach when you have both terms, both the Lindblot term, which comes from basically Markovian dynamics plus all those approximations I mentioned before. And this term, these two terms, which actually come from top three, they don't use assumptions like Markovian or anything because they introduced a little opportunity to go beyond the Markovian, maybe this is part as well. We don't know actually that because you probably know that and from previous talks actually, the criterion for non-Markovianity are quite vast and sometimes they're not even clear which one is which to be applied. But so we in the meantime, we actually quite happy to apply to various systems and let me represent you, give you example of some application. Two level system, such as two level atoms sitting in environments. So we have a two level open quantum system. Obviously, this is one application is two more single atomizer, but it can kill second-level robot approximation in case of those two well Hamiltonian or two well potentials or systems where the distance between a bunch of levels is much larger than the inter-level distances. And let's introduce as an example, maybe pedagogical, let's introduce some technician Hamiltonian. So let's start with the original Hamiltonian which describes bare two level atom and a dipole interaction with electromagnetic field. So it's well known textbook Hamiltonian and let's do a trick. Let's move for this parameters omega note and omega into the complex plane because well for starters, there are probably some physical values and nobody told us from the beginning they should be real valued absolutely. So let's do a little assumption and then relax those real value requirements into the complex domain. And then that way we actually obtain the anti-firmation part which we can safely add to Hamiltonian. And in here, we immediately see the part which has a physical meaning of spontaneous emission which is quite popular in this models which study the curve at and also dissipation of other constant alpha which is imaginary part of omega would be dissipation of that over interaction. So we have created quickly this simply this extension of our original Hamiltonian. And then we, so total Hamiltonian would be our self-adjoint part plus this one, this part which is the spontaneous emission and dissipation and evolution equation would obviously contain this part. And the dissipator can come standard way if you remember in real-world approaching in quantum optics, dissipator has usually this from this plus this one. So all together and remember we also need to switch to remember that our observable so to say dense separator must be actually rho divided by trace rho of this one. Or alternatively we have instead of these two equations we have this just one equation. All right, so with this picture we have a, we create a system evolution equation when you write down as a differential equation. This is our commutator part, anti-commutator part. These two terms is your limb blood part and other remain three terms is also non-hermitian part. So we play, it's from optics textbook are rather plain to a two level is theoretically impossible because we know the population version it requires positive- Konstantin, if you can go towards the end because you have two minutes more. Sure, I'm almost done. So you know that the two mode laser is impossible for describe two level system but interesting that the semiconductor lasers they actually they are approximately two level system. So because they have instead of two levels they have a two bands. So the electrons are happily jumping between all of them and producing a coherent radiation. So the question is how to, how to make a, how to make a model which would be relatively simple yet accurately describe this kind of approximately two level system. And then yes, you can turns out that limb blood type of model would be would probably have problem with it because they as always produce negative contribution into the population difference. And but if you add non-hermitian terms with your Hamiltonian that actually your population difference can be made positive. And therefore you, those models can be used to model those approximate two level lasers at a very low, at very low computational cost. Okay, it's also well, there's also not additional effects which can be seen in the lasers like such absorption emission time and estimatory I'm gonna keep it and go to the reference. So the, basically the talk is basically on this article of me and Alessandro Sergi from University of Messina. We had some applications, we had some community. Thank you very much for your attention. Thank you very much for the talk. Are there questions here? Okay, a line seems nobody's a question. Are there questions here? So I have a question myself. In, so in the, in the mixed formulation can you engineer your limb bloodian and your non-hermitian part of the Hamiltonian in such a way you ensure convergence towards Gibbs measure or things like this?  Konstantin, is this the answer or? No, I think the connection is lost. Hello? Konstantin, what should we do? Yeah, yes, he left. No, I think let me check. He left. So it was really hard question. That's the advantage of online conferences.  I don't know if you will join it again. Well, if not, I think we can go to, we can thank him again, even at least morally. And then essentially we reach the end of.


Hello and welcome to our presentation about attacking and defending mass polynomial comparison for lattice-based cryptography. This is a joint work with Chivam Basin, Jan-Peter Denwerks and Thomas Pöpelmann and it will be presented by Michiel van Beierendonk and myself, Daniel Heinz. I want to start by giving a short introduction about side channel security in lattice-based cryptography and general decryption failure attacks on the FO transform, which is used among many lattice-based candidates. Then we will present two mass comparison algorithms, which were designed to be side channel secure, followed by two attacks on these algorithms showing that they are actually not. Finally we will present our fixed plus noise framework, which is designed to detect such leakages in the near future and to prevent some insecure algorithms. Let's start off with our motivation for our work. As commonly known, the National Institute of Standards and Technology has issued a post-quantum standardization process, which is currently in its third and final round. Apparently the theoretical security of post-quantum algorithms isn't enough in practice and this is why the research focus has shifted a lot towards side channel security. The most common counter measure against side channel attacks is called masking. This is the possibility to split an algorithm in N randomized shares, preventing an attacker from gaining important information about the secret data from N-1 shares. In lattice-based cryptography, boolean and arithmetic operations are used and therefore arithmetic masking or boolean masking is needed. One of the most important tools in lattice-based cryptography to detect chosen cipher text attacks is the usage of the Fuji Saki Okamoto transform. This means that the output, the decrypted message M gets re-encrypted again and the resulting cipher text is compared to the input cipher text. If a non-valid cipher text is inserted, this means that the resulting output cipher text will not match the input cipher text and the output will be completely random. Apparently all operations depending on the secret key, SK prime, have to be masked to ensure side channel security. In our graphics, we have underlayed the respective operations in gray. It has to be stated that the output of the comparison function is public and is not sensitive data, as the knowledge of a invalid cipher text does not reveal any information to the attacker. One of the most important observations in the F.O. transform is that if the message M prime only slightly differs to the message M, which was originally encrypted in cipher text C, the complete output cipher text C tilde will change completely, not just a bit. This is because the message M prime is used as a seed for the randomness used in the Sakaiba or Saba re- encryption. This fact can be used to mount some very powerful decryption failure attacks. To do so, we submit cipher text C equal to U and V plus a very small error E, and this very small error E only affects one coefficient of the polynomial V. This can then result in two cases. The polynomial V is normally only added onto the product of U and the secret key. Therefore, the manually inserted error E can also be only added onto this intermediate value, which we call W in the graphic below. If we don't trigger a bit flip, the message M prime is equal to the originally encrypted message M, and if we trigger a bit flip, the message M will be different to the message M prime in this bit. This means if we can distinguish between the two cases M equals 0 or M equals 1, or if a bit flip is triggered or not, we can receive equations about the intermediate value W and therefore about our secret key, which is inserted in W. When taking a look at the FO transform and no triggered bit flip, it becomes clear that the re-encryption will be exactly the same as the encryption for the originally submitted message M, which corresponds to the cipher text C equal to U and V. Also, the cipher text C tilde will be equal to U and V, as M prime is equal to M. This resides in a comparison, which differs in only exactly one coefficient, which is the coefficient where the error E is inserted. Therefore, the output of the comparison is still no, but it is only different in one coefficient. However, if the bit flip during the decryption is triggered, everything in red will be completely different from the original encryption of the message M. Also, the resulting cipher text C tilde will result in complete randomness compared to the originally submitted cipher text C, and the comparison will therefore output no, as every coefficient will probably be different between C tilde and C. In practice, the decryption failure attacks are not that easy to mount, as for instance, Kuiber and Saber have a compression of the cipher text parts U and V in place. As visualized above, instead of equalities, we only get inequalities about the intermediate value W, and therefore about the secret key. However, it is possible to estimate the remaining security by using previously presented frameworks. In our work, we have used the previously presented decryption failure attack framework to mount some first order side channel attacks on two masked implementations of the comparison in the Fujisaki Okamoto transform. Furthermore, we have identified a collision attack on the masked comparison algorithm of Bache et al, which does not even need side channel information. However, the ideas in this work are still usable, and therefore we have proposed the fix, which reduces the number of needed comparison and probably the needed operation time. Finally, we propose an adaptive leakage detection framework, which differentiates more clearly between sensitive and nonsensitive leakage. Let's move on to the two masked comparison algorithms. The first one is only usable for the first order masking and is based on hashes. We obtain two cipher texts, the re-encrypted and the submitted cipher text. The algorithm performs a separate comparison for each cipher text part U and V. Therefore, we have two shares U1 and U2 and compare if they are equal to the submitted cipher text. To prevent sensitive leakage, the randomized share U1 is subtracted from the public polynomial. In case both polynomials are the same, meaning the public and the re-encrypted, the share U1 is then equal to the share U2, and hashing them both at the same time and comparing them would result in zero. Otherwise, some value other than zero would appear. The approach from Bache et al is quite different, as it works for higher orders as well. We have a shared polynomial and a public polynomial, and we divide each of these into subsets of coefficients, which we call ij. Without loss of generality, we take a look at the subset i1. Each of these shares and also the public polynomials is first multiplied with some randomness. This randomness is the same for each share and also for the public polynomial. Then all coefficients in the subset i are summed up, and therefore we obtain a randomized value in each share and also in the public polynomial. One can then simply sum up over the randomized shares and compare the value with the public value. If the polynomials were the same in the first place, this result will always become true. However, if the polynomials are different and therefore completely different, this result will only become true if every randomness coefficient was zero. If the subsets are chosen largely enough, this probability is assumed to be negligible. One can now repeat this process for every subset ij. The outputs of each comparison or each partial comparison of the sets ij are stored unmasked, and Michiel will now explain how this can be exploited for a first-order side-generator attack in the same way as the first-order method with the hashes from order at the item. Hi, I'm Michiel van Berendonk, and I'll be taking over from Daniel to talk about our attacks on these two mass comparison algorithms. Then I'll proceed by describing our fixed plus noise framework, which aims to catch sensitive leakages in such implementations, and finally I'll conclude our talk. The main idea of our attack is to submit ciphertext in two classes, exactly as in the introduction. On the left, we submit ciphertext with a small error, denoted as e minus one. This error is small enough that it doesn't introduce a bit flip in the message m prime, and correspondingly the re-encrypted ciphertext will only slightly differ from the submitted ciphertext. The slight difference is exactly at the location where we introduced the error, which in our case is the polynomial v. An important consequence of this is that the polynomial u is unchanged, and that it's submitted and re-encrypted versions are equal. On the right, we submit ciphertext with incremental error e. e is only incremented by one from e minus one. This time, e is large enough to trigger a bit flip, and the submitted and re-encrypted ciphertext will differ completely. Even though the f4 transform will detect both classes of modifications and produce the same bit of information in both cases, and this bit of information is that the ciphertext is rejected, the same doesn't hold true for side channel information. In particular, the crucial observation here is that the hash-based method unmasks a partial comparison of u. On the left, this comparison is true. On the right, this comparison is false. We expect this information to show up in side channel traces because it is unmasked. Therefore, it can reveal us exactly which value for e results in the case shown on this slide, where e has a bit flip, whereas e minus one does not. We mount our attack as a simple fixed versus fixed t-test, where either fixed class is the ones are the ones we just talked about. On one hand, we have a class with the error e minus one. On the other hand, we have a class with the error e. Then, we collect side channel traces from either class, we partition them into the classes, and we compute the t-setsistic. This is shown here on both figures, where on the left we show the t-setsistic after as little as 1000 measurements, for the errors e equals 4, e equals 5, and e equals 6. On the right, we show the evolution of the t-setsistics throughout these measurements to show you how quickly the leakage is caught. When e equals 4, the error is too small that both e and e minus one do not cause a bit flip. When e equals 6, the error is too large, both e and e minus one cause a bit to flip. Exactly when e equals 5, both classes of measurements are different. e has a flip in this case, whereas e minus one does not. The resulting t-setsistic, shown in black here on this slide, shows a large peak. The point in time where this peak sits is exactly at the unmasking of the comparison of u, the polynomial, which is unchanged. In one class of measurements, this comparison is still true. In the other class of measurements, it is false. Our attack on the higher-order method proceeds very similarly. Here, instead of comparing and unmasking both ciphertext components, the comparison proceeds in a number of sets. On the figure here, there are exactly 16 sets. Again, for e equals 5, we can clearly distinguish t-test leakage. For the error e minus one, only one of the sets will fail the comparison, whereas for the error e, all sets will fail. We can clearly distinguish 16 leakage peaks corresponding to the unmasking of each of the 16 sets. On the higher-order method, we can also mount a collision attack that doesn't need any side channels. As we just mentioned, the method splits the comparison into several sets. Each set also has a certain probability that the ciphertext modification will pause the comparison. This is exactly the probability that one of the randomly sampled values takes on the value 0. This will be 1 over q, in our case. One of the explicit assumptions in the method then is that the faulty ciphertext results in a completely different re-encrypted ciphertext. In this case, such a collision where the randomly sampled value takes on the value 0 will need to happen in all of the sets. The probability for this to happen becomes 1 over q to the power of L, where L is the number of sets. L can then be chosen for sufficient security. However, we have just shown that this assumption that all sets will fail for a modified ciphertext doesn't hold true. We can submit ciphertext as shown on the left here on this slide, where the ciphertext modification is small enough that only one of the sets will fail the comparison. This allows us now to mount a simple cc attack. We submit some faulty ciphertext and if we're on the left side of this slide we expect to eventually pause the comparison, because the collision probability is now only 1 over q. If we're on the right, we will not pause the comparison because the collision probability is 1 over q to the L, where L is chosen for sufficient security. Again, this will allow us to distinguish between both cases and learn the value E that exactly partitions us into the case here on this slide. From there we can learn the sensitive value w, and this information can be used to significantly reduce the security and break the schemes. The fundamental flaw in both of the schemes is that they unmask partial comparisons of the ciphertext. While the final yes or no bit that is the output of the FALT transform does not contain any sensitive information, the same certainly does not hold true for the information contained in these partial comparisons. The hash based method permits a simple fix. Instead of comparing both ciphertext components individually using the hash based approach, it is possible to simply concatenate the ciphertext and hash both of them together. This method was already employed in a mask implementation of Saber and in this case the final unmasking no longer contains any sensitive information. For the higher order method the situation is led straightforward. Even if the mask sum which is now done on each set individually would be done over all the sets jointly, the collision probability of this still remains one over Q. Furthermore the security proof did not take into account that slightly modified ciphertext will still result in a re-encrypted ciphertext that is highly similar and in this case there is actual leakage of information when the final sum is unmasked. Because of these two issues there is no straightforward fix to the higher order method. However the ideas from this paper can still be reused to reduce the number of comparisons that are necessary in a mask implementation. We propose such an algorithm in our paper and call it reduced comparisons. The main idea is that if we repeat the mask sum over the entire ciphertext L times then the collision probability does become one over Q to the power of L. Furthermore we do not do any final unmasking but instead propose to simply use a masked Boolean comparison circuits as has been done before in the literature. In our work we find situational vulnerabilities in two mask comparison algorithms. To prevent such issues from happening in the future we propose a new framework which we call fixed plus noise. Before describing our framework an important question to ask is why the standard t-test did not detect the leakage that we saw in the previous slides. To answer this question it's important to first look at the specific way that the t-test was applied in masked implementations. The typical scenario is to conduct a fixed versus random t-test. In this case often the fixed ciphertext will be the ciphertext that is the output of the encapsulation and the random ciphertext is chosen completely random. One of the problems with this approach is that the fixed ciphertext will now be a valid ciphertext whereas the random ciphertext will be an invalid ciphertext. As a result there will be output leakage of the yes or no bit that is the output of the full transform but as we previously mentioned this output bit is nonsensitive. On this slide we show the resulting t-statistic for such a fixed versus random t-test. On the left we have the hash-based method and on the right we have the higher order method that partitions the comparison into sets. In the middle is the fixed method that was applied in the masked implementation of Saber where the hash-based method proceeds by concatenating the ciphertext components. In a fixed versus random t-test where the fixed ciphertext is valid and the random ciphertext is invalid all of these implementations show output leakage. This is exactly the leakage of the yes or no bit that is the output of the full transform. However something that might look very obvious is that this leakage is very similar to the leakage we exploited in our attacks on these implementations. In the standard fixed versus random t-test that's applied here on this slide it is very difficult to distinguish between sensitive and nonsensitive leakage. We propose to conduct the t-test differently which we called fixed plus noise versus random. The main idea is to choose both ciphertexts as invalid ciphertext thus eliminating the output leakage. The fixed ciphertext contains a small noise whereas the random ciphertext can still be taken essentially completely random. Our method is similar to a semi-fixed versus random t-test in the sense that it fixes the output bit of the full transform to reject the ciphertext. When applied to the mass comparison implementations it can immediately be seen that two of them are insecure whereas only the middle one is secure. The hash-based method and the higher order method shown on the left and on the right still show leakage in this case. This is exactly because the fixed plus noise class of the measurements will only cause one of the comparisons to fail or will only cause one of the sets to fail for the higher order methods. On the other hand the random class of measurements will cause all of the comparisons to fail. This is very similar to what we exactly exploited in our attacks with the only exception that we're now no longer really looking for the border case value that triggers us in either one case. In the middle implementation there is no longer any leakage. This shows that the leakage that we saw on the previous slide was indeed only the nonsensitive leakage of the full transform. On the other hand using our fixed plus noise framework it can be shown that the same does not hold true for the hash-based method and the higher order method. These methods leak more information than only the one output bit of the full transform and this information can be exploited to mount the attacks that we described previously. In our paper we further analyze our framework and we also provide a code snippet so that you can conduct the fixed plus noise versus random t-test yourself. To conclude our work we attack two mass implementations of polynomial comparisons in the ful transform. We could do so both with the first order side channel attack as well as with a collision attack that does not need any side channel information. We also showed how to modify the methods to prevent the sensitive leakage. Finally we propose the new fixed plus noise versus random framework that should serve to detect these insecurities in the future. We propose to reduce comparisons as a straightforward fix to the higher order method but we believe that there is interesting future work in a more efficient higher order mass comparison method. We would like to thank you for listening to our talk and do not hesitate to reach out to us if you have any questions.