Hello, welcome to my talk. My name is Daniela Escudero and I'm going to present my joint work with Ivan Dankar, Divya Rabi on information theoretically secure NPC against mixed dynamic adversaries. And I want to state that a manipulation of GP Morgania research, but this was a Work done while it was at Orhus University. So let's first recall what secure multi-party computation is. In this setting we have a set of multiple parties, which I'm labeling P1, P2, P3 up to P8 and they are connected in point-wise channels. So they have peer-to-peer channels and their goal is to securely compute certain functions. So each PI has a secret input, which we denote by Xi and we consider an adversary that corrupts T out of the end parties. And the idea is that at the end of the protocol execution, so they are connected by these channels, they exchange a lot of messages, they interact among each other, and at the end of the protocol the idea is that the parties get the output of certain function that they choose evaluated on their inputs and that only this is revealed. Nothing else about their inputs is revealed except from this output. So this is the general goal of NPC, this is the general premise, and we have several results, in particular in the domain of information theoretical security, which is what we are concerned with in this work. We have the following two main results. So for a passive adversary, which is an adversary that corrupts the parties in a passive way, meaning that it can see the messages they receive, the messages they send, and also their internal state, but it cannot change their behavior. So they will follow the protocol execution, the protocol specification faithfully. Now for a passive adversary, which is a very weak adversary, we know that we can get perfect security assuming that 2T is less than N. Perfect security meaning that the protocol is essentially unbreakable, like no matter how many resources the adversary has, how powerful it is, it will not be able to break the protocol because statistically everything is hidden, like perfectly hidden. Now against an active adversary, which is a more realistic adversary, it can essentially change the behavior of the corrupt parties arbitrarily, so it's an adversary we really would like to consider in practice, we obtain the following results. If we want to have perfect security, then we have to go for a stronger bound on T. So instead of having 2T less than N, we have to have 3T less than N. So the adversary can only corrupt a third of the parties if you want to have perfect security. And you want to have statistical security, which is a slightly weaker version of information theoretic security, meaning that the protocol has a very slim, very small chance of failing. You can get back to the 2T less than N domain. So these are standard results and an interesting fact is that you can also consider mixed adversaries. So this was considered in this very important work from KryptonID8. And the idea is that now we want to consider an adversary that simultaneously corrupts some parties actively and some parties passively. And even on top of that, we will consider what we call fail-stop parties, which are some parties that the adversary does not control, the adversary cannot see their state, it cannot alter their behavior. And the only thing the adversary can do on these parties is make them stop, so the adversary can cause them to crash, basically, and stop sending and receiving messages. It's like a way of cheating with these parties, but it's of course not as harmful as the adversary being able to read the state or the adversary being able to modify their behavior completely. So when we consider mixed adversaries, this work that I'm citing here brings the following results. For perfect security, we can get it as long as 3TA plus 2TP plus TF is less than N. So if this is exactly a generalization of the bound we knew before, because before we had that perfect security was possible, if 2T was less than N, if the corruption was passive, and 3T is less than N, if the corruption is active, we can see it here.  So this is a strict generalization of the previous results. And for statistical security, we get a similar inequality, except that now we get a factor of 2 here instead of a factor of 3. And these are very important results, and this is the first work that consider mixed adversaries. So adversaries can simultaneously corrupt parties actively and also possibly. So let's try to understand in more detail what these results I just mentioned mean. They mean that for every tuple you consider, so for every three numbers you consider, such that 3TA plus 2TP plus TF is less than N, I'm talking about perfect security here, of course, just for illustration purposes. For every such tuple, there exists a protocol that is perfectly secure, as I mentioned, this is the example of perfect security, against TA active corruptions, TP passive corruptions, and TF fail stops. So again, for every tuple you choose, if it satisfies this inequality, then there will exist a protocol with these properties. And the general idea in this paper is actually relatively simple, is just use Shamir's secret sharing with the degree equal to TA plus TP. Now Shamir's secret sharing has the property that no set of shares that are as large as the degree can leak anything about the secret, and in particular because an adversarial corrupting TA parties actively and TP parties passively can learn exactly TA plus TP shares, because it can see the states of these two shares, of these two parties. Then we can see that privacy holds in this case, because we're choosing the degree so that no set of TA plus TP shares reveal anything about the secret. So privacy will hold because the adversary can only see the state of TA parties plus TP parties, and also because of this bound here, together with the choice of the degree, you can show that error correction holds. So for error correction techniques to hold, certain inequality has to hold between the number of errors and the number of shares that you get at the end and the degree, and well that inequality will hold in this case with this choice of parameters. And error correction is a method that allows you to at the end of the protocol get the result. So this is the general reason why this choice of D will work. So again, in the mixed adversary setting that we just saw, for every tuple that exceeds the protocol. So for example, if you set n equal to 8, and you choose TA equal to 2, TP equal to 0, and TF equal to 1, well, 3 TA plus 2 TP plus TF is equal to 7 in this case, which is less than 8, the number of parties. So in this case, we know that there exists a protocol such that it supports two active corruptions, no passive corruption, and one fails of corruption. So we know it exists because of the theorem. If instead of that, you choose TA equal to 0, TP equal to 3, and TF equal to 1, again, the sum with the appropriate weights is equal to 7, so it's less than 8. In this case, there will exist another protocol. This can be an entirely different protocol by prime that supports no active corruptions, three passive corruptions, and one fails of corruption. So this is just an illustration of what these results mean. You can choose a tuple, and there will exist a protocol. You can choose another tuple that satisfies the same inequality, and there will be another protocol, and in principle, it can be different. So what we want to study here in this work is dynamic NPC. So in a nutshell, we can see dynamic NPC as a way of reversing the quantifier's order. So in the previous result, we had for every tuple, there exists a protocol. So instead of having these, here we have for every tuple, there exists a protocol. Instead of having these, we want to have that there exists a single protocol such that for every tuple, we get some notion of security. So we want to reverse the order of the quantifiers. We don't want to design a protocol specific to every single tuple that you can come up with. We want to design a single protocol that works for every tuple. As an example, we would like a result of the following type. There exists a protocol such that for every tuple, such that they are prepared in equality holds, the protocol is perfectly secure against an adversary corrupting TA parties actively, TP parties passively, and TF fails stops. Now this result won't hold. Like exactly as I stated here, this result will not hold, but we will be able to show more concrete results about when does this hold and how does this hold. But this is just an example of the type of results we would like. It's very different from the one we had before. Before we had for every tuple, there exists a protocol, and now we have there exists a protocol that works for every single tuple. And I want to begin by illustrating why this is difficult. This is more challenging than the things we had from before. And the main reason is that the protocol does not know the concrete values. You want to design a protocol that works for any tuple such that some property holds. It can be 3TA plus 2TP plus TF less than N. You don't know anything about TA, TP, TF except that they satisfy this inequality. And as an example about why this will be hard, let's go back to the case in which N is equal to 8 and assume that you want to design a dynamic secure protocol, but still use the same paradigm of using Shamir with this degree. So you use Shamir with this degree and let's say that you use exactly the degree equal to 2. So let's say you begin with degree equal to 2. In this case, if the tuple TA, TP and TF happens to be 201, respectively, then you can get privacy because the maximum amount of shares that the adversary learned is 2 plus 0. So you get privacy. And you also get error correction. You can check that the error correction bound will hold. This is essentially the construction that you would get from the previous mixed adversary construct papers. But now, if you choose this D, this protocol you design should work for any tuple, not only for this tuple. So what if you also consider this new tuple, 031? Well, this D will not work for this new tuple because now in this new tuple, it is still, this new tuple still preserves, it still satisfies the bound because 3 times 0 plus 2 times 3 plus 1 is less than 8. So your protocol should be secure against such tuple, but it's not because the degree is 2 and the adversary can see 3 shares because it can corrupt 3 parties passively. So there will be no privacy. Sure, there will be still error correction. This is trivial because there are no actively corrupt parties actually, but there is no privacy. So if you choose this D, it will not work against this tuple. It may work against some tuples, but not against this tuple in particular. So let's say you change and you choose D equal to 3, you increase D because the problem was privacy, you just increase it and now everything should work. So now, you have privacy and you also have, you can show that you also have error correction again because a TA is equal to 0. But sure, maybe now with the choice of D equal to 3, now you get your protocol to work for the tuple below, but for the tuple on top, your protocol simply will not work because maybe you will have privacy because the degree is 3, which is larger than 2, the maximum number of shares the adversary gets, but now you don't get the error correction. You can check that the, it is possible to check that the error correction bound will not hold in this case. So the conclusion is from this slide, if you choose this fixed degree for your protocol, it will work for this tuple, but not for this one. And if you choose this degree, then it will work for this tuple, but not for this one. So this is the challenge in designing dynamically secure protocols. You cannot simply go and choose one single tuple, one single paradigm, one single degree. You have to be more dynamic. Well, as the name implies, you have to be a little bit more flexible in the, in the way you design your protocol. And this is basically the main difficulty in designing these techniques. So I want to, to mention that there are previous works in this direction, in the, in the direction of designing a dynamically secure protocols. So we have these work from crypto 13 by her at all, where they do introduce the concept of a dynamic adversary actually, and they consider these adversaries in the computational security setting. So what you do, where you make computational assumptions. This is in contrast to our setting here, where we consider information theoretic security. Now, in very recent work, 19, in Patra and Ravi, it considered the setting again of computational security, but this time in contrast to the work on the left, they consider round complexity specifically. So they prove some lower bounds in the round complexity. And they prove that a certain protocols they design would be optimal with respect to these lower bounds. Now, I should also mention that there is this work that a, even though it does not, it's hurt at all, but even though it does not consider explicitly a dynamic adversary, it's still related to it because you consider general adversaries or general structures of adversaries. And it is not hard to see that a dynamic adversary is just a much more flexible or larger collection of a, it's a larger adversary structure. And they consider this is exactly what they consider in this work. So we do a more third of a comparison to this paper in our work. So we invite you to read it there, but the conclusion is basically they do achieve some feasibility and impossibility results, but because they consider arbitrary adversarial structures, their results are essentially polynomial on the size of the structure. And well, for threshold structures, like the ones we consider here, this size of the size of the structure is actually exponential. It's very large. So our results are more meaningful feasibility results for the concrete case of threshold structures. Okay. So what are our results? The results we achieve here are the following. So for statistical security, we have to assume the bound from the non-dynamic setting. This is the bound from the work I cited at the beginning for the mixed adversary. We have to assume that these bound holds. Otherwise, we cannot even hope to get protocols in the dynamic setting if they cannot be obtained in the non-dynamic setting. So in this concrete scenario, statistical security, we get the following two results. For secure function evaluation, which we abbreviate with SFE, this is the part that just provide input and get output. In this setting, we show that GOD protocols are possible to design. So this is a very good positive result. But unfortunately, even if you only require fairness, not even GOD, you need to have a number of rounds that grow linearly within, asymptotically speaking. So the number of rounds of this protocol grow linearly within. And this is very bad because you can have, in the non-dynamic setting, you can have protocols with very low round count if the function is simple enough. For example, if the function is in NC1. So in these cases, in NC1 or NC0, you can get constant round protocols, but in the dynamic setting, it's impossible to get this protocol. So this shows a strict separation between the non-dynamic setting and the dynamic setting. Now, for reactive NPC, which is where you get input, you get output, and then you may reuse this input again. And this reactive NPC can be obtained basically from SFE and verifiable secret sharing. In this setting, fairness is possible, but GOD requires in addition that R, the maximum between TA plus CP, and F, the maximum between TA plus TF, is less than N. These R can be interpreted as the number of shares or number of states that the adversary can read. It corresponds to active and passive parties. And F corresponds to the number of parties the adversary can cause to crash, which is the active parties and the ones that are fail-stop. So this is in terms of statistical security, and in terms of perfect security, where we assume the corresponding bound from the non-dynamic setting, so essentially the same as before, but with a tree here, we show that SFE is actually impossible. And this is a very interesting result. Even with a board, it's still impossible, even if you, if the adversary is restricted to not make any fail-stop corruption, it's still impossible. But fortunately it's possible in some cases. For example, we explore the case in which you restrict the adversary to not make any active corruption, and in that case, we show it's possible. Or alternatively, if the adversary does not corrupt any party passively, it's also possible. But we did not explore the exact conditions under which it is actually possible. For reactive MPC, we show that GOD verifiable secret sharing, so verifiable secret sharing where the output is guaranteed to be obtained at the end, is impossible. And this remains to be the case even if there are no fail-stop corruptions. However, we show that GOD VSS is possible in some cases again. So if, for example, if we were 68 to be zero, so no active corruptions, and we also assume this extra bound, we can show that in this case it's possible, and actually we can show that this bound that I'm saying here is also optimal in this case. Same for the results here. If there are no passive corruptions, we need to assume this extra bound, and we show that indeed this is the case. You need to assume that bound. And I'm also not mentioning this slide, but fair VSS is possible whenever secure function evaluation with perfect security is also possible. So these are overall our results, and now I would like to proceed to describing the techniques that we use to achieve such results. So let me begin by describing our results on a statistically secure SFV with GOD. We show that this is possible. And first, the setting, again, we assume the bound for mixed, dynamic mixed adversaries, sorry, in the statistical setting. But furthermore, for simplicity, we will assume that TP is equal to zero. So actually, this term disappears and the bound is to TA plus TA less than it. This makes sense. This is not artificial. This makes sense because you can see that both passive and active parties have the same factor, the same weight. Both of them have a factor of two. So for the adversary, it costs the same in terms of in terms of threshold to corrupt an active party or a passive party. So it makes more sense to consider the strong adversary that only corrupts parties actively. So we have this bound, and we also assume in addition that parties can detect when another party fails stops. And this is, again, not artificial. Also, we can have a broadcast channel in which parties broadcast constantly some harbids, mentioning that they are alive. And whenever a fail stop party crashes, it will simply stop sending these harbids. And whenever a party stops sending these harbids, it's considered to be fail stop. So this is the general layout of our protocol. I'm going to start with a bigger picture and then we're going to consider the small details. So first we're going to assume a box, which is a non-dynamic protocol, also a traditional protocol just like the ones that we always knew they exist. A classical protocol, non-dynamic with GOD, tolerating TA less than and half corruptions, active corruption. So this is a protocol that tolerates dishonest minority, and it's non-dynamic. We know a lot of these protocols. Now, the parties are going to provide the inputs to this protocol. And in the protocol execution, they will restart if some fail stop is detected. I want you to notice that because 2TA plus TF is less than N, if you remove a fail stop party, you remove one from here, you remove one from here. So the new values will still satisfy the same inequality. And finally at the end the protocol will produce output. Now, what is the output? The output is not exactly Z. So Z in this case is the function that we want to compute. But the output that we want to produce with this protocol is not exactly Z in the clear, but it's a shared version of Z that I'm going to describe in a moment. Why do we want a shared version of Z instead of having Z in the clear? Let's say that we modify this protocol so that instead of producing shares of Z, we produce Z. The problem of doing this is that the adversary may cause some fail stops towards the end of the protocol. So when the protocol is about to end, for example, it can make a lot of parties fail stop. And the adversary will learn output while the other parties will not. This will not be fair. In particular, it will not satisfy guaranteed output delivery. And the reason why this happens, even though the protocol is assumed to satisfy guaranteed output delivery, is because the protocol is assumed to satisfy this property in the non-dynamic settings. So it is assumed to tolerate active corruptions, but it's not assumed to tolerate fail stops. So this is the problem. This is why we need to have a different approach. So we're going to have a shared version. I'm going to describe what this shared version means. So what this means is that at the end of the protocol execution, again, if this protocol, if some fail stop is detected in the middle of the protocol, the protocol restarts. This is not a problem, by the way, because nothing is leaked because of the properties of the protocol. Absolutely nothing is leaked about the output at any time. So you can always restart because the adversary can change its inputs or something, but it will never learn anything related to the output. This is also the case because the output, again, is not in the clear, is shared. So the second step is that the parties are going to engage in a protocol that enables them to reconstruct this shared version of Z. And now after the reconstruction, they will get indeed C in the clear, which is what we ultimately want. What are the properties that we want from this reconstruction protocol? Well, there are mainly two properties. So the protocol has to be fair, meaning that either the output succeeds or the adversary learns nothing. And this is not trivial to achieve because, again, as I mentioned, if up here we remove these brackets, we try to output the result in the clear, this will not be fair because the adversary can always make a lot of parties crash at the end. It can learn all their values and it can remove or it can prevent the honest parties from learning these results because a lot of parties crash at the end. This is a good moment to mention, by the way, that we assume the adversary is rushing. So it means that the adversary can choose to first hear the messages from the failed parties and then make them crash before these messages reach the honest parties as well. So this is why getting fairness is really, really difficult. And then, so this is the first property we want from this reconstruction protocol. It's not trivial. It's actually one of the main complex parts. And we also want that if the protocol aborts, so if it, again, if it does not succeed, if it aborts, we know that the adversary learns nothing. But we also want, in addition to this, that the parties identify some set of active or fail-stop parties. So it doesn't simply abort and say it's this failed, but also it failed. And by the way, these set of parties are guaranteed to be actively corrupt and these set of parties are fail-stop. At this point, when they can identify these parties, they can simply restart. So we do the same here in the second part. They start interacting in this reconstruction and at some point, they, it fails. This reconstruction aborts. So then the parties will go back here to the beginning of the protocol, but now removing the identify active parties and removing the identify fail-stop parties. This is secured to do because of the fairness property. Nothing is leaked about the output whenever an abort occurs. Never, never the adversary learns anything about the output. So this is why we can sort of go back to the beginning and restart the protocol. And well, you can intuitively see that if we restart this thing a lot, every time we are kicking out some parties, so eventually this will succeed and eventually this will result in the output. So basically, this is the layout. This is the template. And what we are missing right now is just how to get this box. How to get this box in such a way that it's fair and in such a way that whenever you abort, you identify some, some parties. And again, just, just to mention it, the hard part is getting fairness. Intuitively, is because you can like reconstructing things in a fair manner is difficult. If you have an adversary that can first get the messages and then choose to prevent the other parties from getting them. This is the main interesting part. So how do you get the fair reconstruction? Well, we're going to have some notion of sharing. So the notion of sharing that we're going to use looks like this. You're going to have some random value that is given to the parties in point-to-point channels at the end. And also you're going to have some secret shares. So these square brackets actually mean Shamir secret sharing with some message authentication codes that allows parties to detect incorrect shares. So the details are given in the paper, but for now it's just, it's just good to think of it as Shamir secret sharing with some additional information that allows parties to detect whenever a party, whenever an actively corrupt party send an incorrect share. So we're going to have some r for the shared representation of z. We're going to have some r and then a series of shared values where the sum of all these values, z1 up to zl gives you the masked version of z. So it gives you z minus r and also each zi is secret shared with the degree corresponding to its index. So zl is secret shared with degree l, cl minus one will be secret shared with degree l minus one down to z1 that is shared with degree one. And here l is chosen to be this quantity here, which is the maximum amount of actively corrupt parties the adversary can have. In particular this is private because the adversary does learn, it cannot, it cannot learn in particular this value because it has a very large degree, it cannot get enough shares and because it cannot learn this value, it cannot learn this value. These type of sharing are called leveled sharing and they were introduced in the original work, the first notation I gave on the dynamic NPC setting. So with this type of sharing, whenever you want to reconstruct a secret shared value, we do it like this. First for d equal to l down to one, you reconstruct each degree. So the parties begin trying to reconstruct this one. Then they reconstruct the next one up to, until the last one, they try to reconstruct z1. Either each of these, because we're using Shamir secret sharing with max in the honest majority setting, where you only have error detection, you don't have error correction, the protocol can fail. So either the protocol succeeds, but if it fails, the good thing is that because we're using max and the way that everything is designed, the parties will be able to identify kA, kA active parties and kF felt sub parties such that the degree is greater than or equal to this quantity. This is a rather standard when we use max with Shamir secret sharing, but to give you an idea about why this works just very intuitively, whenever you try to reconstruct shares with this degree, everyone will announce their shares and their max and their tax, and maybe the corrupt parties, the actively corrupt parties, and maybe the felt sub parties won't do this. So for sure, you're going to have n shares at the end because they are announced by other parties, but you have to subtract the possible ones that will not be broadcasted, that will not be sent, which are the ones corresponding to the actively corrupt parties and the ones corrupt into the felt sub parties. So this is the number of shares that the parties have at the end. And if these are larger than d plus one, larger than or equal to d plus one, then they can't reconstruct because this is larger than the degree. So if they could not reconstruct this because this quantity was not larger than that, so it's smaller than or equal to d. This is an intuition why if the reconstruction of cd with degree d fails is because a lot of parties misbehave actively and fail stop. And the number of shares obtained at the end was not enough. So this is upper bounded by d. So this is the property of this secretary scheme. You can reconstruct by starting with the larger degree down to the lowest degree. And if one of these reconstructions fail, then it's because the parties can identify certain number of active parties, certain number of felt sub parties such that this inequality holds. This will be important later on. So let me claim the following. Assume that d is greater than one. We claim that if the reconstruction of zd with degree d results in abort, then the adversary does not learn the next value. And this is enough to get fairness because it means that maybe the adversary when they are reconstructing zeal, maybe the adversary gets to learn zeal. And again, the reconstruction of Shamir values, Shamir playing values is hard to make fair. So maybe the adversary can learn zeal and no one else learns zeal. This may sounds like like a breach for fairness, but it's not because the claim shows that even though the adversary learns the value, the adversary will not learn the next one. And the adversary needs all of them to be able to get z. So this is why this will give you fairness. So if the adversary cheats in opening zd, it will not get zd minus one. By the way, this is assuming that d is greater than one. The case of d equals one is handled slightly different and I leave the details for the paper. So I defer you to that. So how do we prove this claim? So first we know that if the reconstruction of zd with degree d results with degree d results in abort is because there are at least Ki, Ki active parties and Kf felt so parties such that these inequality holds and the parties can identify these these the honest parties can identify these set of parts. So in particular, if there are Ki active parties, we don't know anything about TA TA is the number of active parties the adversary chose to corrupt. We don't know anything, but because we know we identify at least Ki of them, well, TA has to be for sure greater than or equal to Ki and the same for TF TF has to be greater than or equal to Kf because we identify Kf first parties. So now we can bring all these inequalities together. Also with the help of the one we started with, which is the the main inequality for statistical secure and PC to TA plus Tf less than n. And when we combine them, we essentially get we essentially get this beginning quality. So we essentially get that D is greater than TA. So the adversary has less than these shares. Why is this? Well, the adversary disrupted the reconstruction of zd. So everything stopped there, the protocol stopped there. So the so regarding the shares of CD minus one, the only thing that the adversary has is the shares from the corrupt parties, because he never received any message from for that for that reconstruction, because the protocol stopped before the reconstruction. So the adversary only gets TA shares, but they are less than D. And if you want to reconstruct a degree D minus one sharing, you need, well, at least D. So this shows that the adversary who only has TA shareings does not have enough to reconstruct this sharing down here. And this is why the claim follows. So with this, we conclude the proof of the upper bound. I would like to recall again, this means that we can get a statistically secure protocol for secure function evaluation in the dynamic setting. And I roughly gave you an idea of how it worked, a general template. So now I would like to bring your attention to the lower to the lower bound for these protocols. And the interesting thing is that if you notice this protocol needed to restart a lot. So bringing you back to where we had the template of the protocol, the protocol had to go back a lot.  And in the worst case, it can go back a lot of times. It can go back, essentially a number of times that is proportional to the number of parties, because in every rerun, a new corrupt party is identified. So it has a running, it has a round count that is proportional to N. And what we show here is that being proportional to N, having a round count proportional to N is actually inherent. So to show this, we're going to suppose that there exists a dynamic and also fair, a statistically secure protocol with exactly N fourth rounds. And we're going to show that this is not possible. So let's get started with the lower bound. To this end, consider first the following scenario. So we have the N parties here. And the adversary chooses the following corruptions. It chooses to corrupt actively the first N fourth parties. It chooses to make the middle N have minus one parties to fail stop at some point. And while the remaining parties, which you can compute will be N fourth plus one, they will remain honest. Again, here we're assuming by the way that 2TA plus TF is the N. And you can see that these satisfy these bounds because 2N fourth plus 2N half minus one would be exactly less than N. So this is the first scenario. This is the adversarial structure. This is what the adversary chooses. And the strategy in the actual protocol execution looks as follows. So R by the way is the number of rounds. In round one, the protocol, the corrupt parties just follow the protocol normally and the fail stop parties also follow the protocol normally. They won't crash yet. In round two, it will be the same. So the protocol execution will continue normally even up to round R minus one. But in round R, when the parties send to each other the last messages they are supposed to send, the adversary will cause the actively corrupt parties to stay silent. And it will cause the fail stop parties to also stay silent. What does this mean? Let's analyze what this situation tells. So here in the last round, these parties will not talk. But remember, because the adversary is rushing, the adversary will actually get the shares, will get all the messages. So at the end of the round, the fail stop parties are supposed to send some messages. The adversary will get those messages, but the honest parties will not. So let's analyze the situation. The adversary learns the output. Why does the adversary learns the output? Because it behaves, the adversary behaves normally during the whole protocol execution. And as I just mentioned, the adversary gets the last messages. So from the point of view of the adversary, the execution just happened successfully. The adversary received all the possible messages in the protocol. And because the protocol is supposed to be well correct, it gives the adversary the possibility or the ability to compute the output. So because the adversary learns the output and the protocol is fair, the honest parties also must get the output. This is the definition of fairness. If the adversary gets the output, the honest parties must get it as well. However, the interesting thing is that the honest parties, even though they got the output, as I just mentioned, they did not get any message in the last round. Because that's a strategy the adversary chose. The messages the parties get here, they only come from among themselves. They never heard from the fail stop parties or they never heard from the actively correct parties in the last round. What does it mean? If the honest parties got the output, but they never got any message in the last round, it's because they knew the output already in the previous round. So here in round R minus 1, the honest parties already got the output. And well, this is a particular strategy that we chose with the adversary corrupting the first set of parties actively and so on. But if you rearrange for any subset, you can essentially prove that any set, by the way, when you do the count again, there are n4 plus 1 honest parties. So any set of n4 plus 1 parties that you choose already know the output in round R minus 1. So not only this subset down here, this subset has n4 plus 1. Any subset you choose down here of size n4 plus 1 already knows the output in that round, not in the last round. Like a subset of this size does not need to go to the last round. If they get together, they already will know the output. So that was one scenario. Now consider this second scenario. Now the adversary will not corrupt n4, but instead of corrupting it fourth actively, it will corrupt n4 plus 1 actively. In addition, it will corrupt, because it's corrupting one more active party, for every new active party, it has to subtract two failed stock parties. So instead of corrupting in half minus one, it will corrupt in half minus three failed stock parties. And the rest will be honest. How many are the rest? You can check it will be n4 plus 2. This is the new adversarial choice. Like this is the choice that the adversary will make regarding the active corrupt parties and the failed stock parties. So the strategy in the protocol execution will be like this. Round one will be just like nothing happened. Everyone will behave honest. Round all the rounds up to round R minus two would be like that. But in round R minus one, the actively corrupt parties will remain silent and the failed stock parties will remain silent. And well, the honest parties, they will only hear from them from among each other, right? Because they never get the messages from these parties of here. Well, and in the rest of the, like they remain silent from now onwards. So let's analyze this execution. It's similar as before. The adversary controls n4 plus one parties, right? This is what the adversary is controlling. It can see their state. And even though the adversary got here, the corrupt parties, they don't speak here. Again, because the adversary is rushing, they will get all the messages. So they will get the messages coming from the failed stock and also from the honest parties. So it means because of the previous result, the adversary corrupts n4 plus one parties in round R minus one gets all the messages. So the previous conclusion leads us to determine that the adversary will learn the output in round R minus one. So the adversary gets the output in this execution. Why? Just to recap again, it gets all the messages in round R minus one and it corrupts a set of size n4 plus one, which is enough to get the output in round R minus one because of our previous analysis in the previous scenario. So now from fairness, because the adversary get the output, the honest parties have to get it as well in round R minus one. But once again, they don't receive any message. They don't receive any message from that round. So they only got the messages from this round. So conclusion, it means that the honest party knew the output already in round R minus two. My apologies for this time. So the party's already knew the output in the previous round. So here, so you can see that what we're doing, we can continue the pattern, we can continue, we can consider a new scenario in which the adversary corrupts not n4 plus one, but n4 plus two parties and then adapts the failed stock corruptions appropriately. And this will bring the adversary to know the output even in a previous round. And if we iterate this argument, we can show that the adversary already knows the output in the first round. So you can essentially collapse this argument down to the first round, but this is impossible. You cannot get a protocol in which the adversary learns the result in the first round because then it can always get the messages from the honest parties and use those messages to evaluate the function on any inputs of its own choice. And this leads to what we call the CDUL attacks. It's not something allowed by the MPC functionality. Okay. So this is essentially the general idea of a lower bound. I know a lot of details are left. I'm not discussed here, but I invite you to read the paper to learn about these details. Also want to mention, this is the overview of our results. This is a chart, this is a table from the paper. So we discussed a GOD as a fee in the statistical setting. And we also discussed that it requires in rounds. Some of the results are similar in terms of the upper bound, but all these results here, of course, I didn't have the time to discuss. So I invite you to read the paper for getting details on these additional results. With that, I would like to conclude. Thank you so much for your attention. Open to questions and invite you to read the paper also. Thank you so much.


And now, great moments in unintended consequences. Part one, Glock Management. The year 2008, the problem? Oakland has too many guns. The solution? Offer $250 for every gun turned into the police. No questions asked. Sounds like a great idea, with the best of intentions. What could possibly go wrong? It turns out, a lot of guns aren't worth $250. But they were that day. People drove for hours, even from other states, to sell their old junk that had been collecting dust. Generally not the kind of weapons used to perpetrate the crime. In fact, the first two people in line at one of the buyback locations were gun dealers, unloading their worthless stock. The program was estimated to cost $50,000, but the police department quickly ran out of cash and had to issue IOUs totaling roughly $170,000. And it would have been even more expensive, except that Oakland had essentially created an open-air gun market. Some guns were actually bought by prospective buyers walking the line and offering $300 for specialty items. Talk about a misfire. Part two, Poppycock. The year 2002. The problem? Farmers in Afghanistan are growing poppies for the illegal drug market. And after all we've done for them. The solution? Cash for poppies. A $30 million program to pay farmers $700 an acre to destroy their crops. Sounds like a great idea. With the best of intentions, what could possibly go wrong?  Poppy cultivation exploded with many thoughtful Afghans making sure to harvest and sell the valuable sap on the black market before destroying the remaining plants to comply with the program, getting paid twice for the same crop. The project was such a fiasco that one British agricultural expert called it an appalling piece of complete raw naivete. Put that in your pipe and smoke it. Part three, fuels errand. The year? 1975. The problem? Cars are using too much gas. The solution? Improve average fuel economy by penalizing automakers who fail to meet efficiency standards categorized by vehicle size. Creating more stringent targets for passenger cars than for trucks used in farm work and commercial hauling. Sounds like a great idea. With the best of intentions, what could possibly go wrong? Turns out car manufacturers don't like paying fines. In order to comply with the new rules, automakers began making their cars bigger. Voila! More crossovers, SUVs and minivans, all of which technically meet the government definition of a light truck. That's why this Lexus NX is actually considered a truck. So is this RAV4 and this Subaru Outback. In fact, light trucks now account for almost 80% of all new vehicles sold. Way to truck things up. Great moments and unintended consequences. Good intentions, bad results. Do you know any great moments and unintended consequences? Put them in the comments below. Unless they're personal, don't put personal things there.


How do you design organizations for sustainability? How do you create social enterprises for the digital economy? If you've been thinking about these kinds of questions, you should come to our summer school. The chances are that you've used the Uber taxi app to get around town or you've used Airbnb to travel and that you've used Amazon to do some of your shopping. But have you ever wondered about the impacts of these new technologies and innovations on society and on the economy more broadly? So the digital models that these companies are using are interesting, they're efficient, they're very convenient, they generate awesome benefits for shareholders, for investors. But they don't always distribute those benefits very evenly and they don't always take into account wider issues of impact, wider issues of sustainability and prosperity. Along with academic experts who know a lot about the measurement of prosperity and the creation of business models, we're bringing in actual entrepreneurs from the digital economy. We're bringing in social entrepreneurs who are reconfiguring how the labor markets work. We want to learn from real examples that are being developed right now here in London.


Did you have any goals as far as power numbers were concerned coming into the season? I mean, yeah, I wanted to try to hit 20. And ultimately stay healthy throughout the whole year was a big thing for me. I was able to do that today. Please, by the fact that you were able to do it with a lot of season left to build on? Yeah, I mean, me and Jesy were talking about it. When I had 18 of that, I kind of want to go 19-20 and not get stuck all 19. So, yeah, it was fun to be able to do this early. Neil Walker, hitting homeruns from both sides of the plate. As a guy that swings it from both sides of the plate, can you describe how hard that is to be dialed in and to homer in one game from both sides? It's special. You know, it was fun to see him do it today. You know, I feel like switchers are kind of a dying breed, and it was fun to see him do it today. What's the feeling like in a dugout during the game like this when everyone is seeing all these balls fly out? It's fun.  Giancarlo San hit the hardest hit ball since StadCast came into existence in 2015. Are you in awe of the way he hits them, how hard he hits the ball at times, or what's your reaction when he hits a ball 121.7 miles an hour off the bat? I mean, I think it was at like 17 degrees or something, so for the rest of us, I think that's just a normal base hit. And for him, it's a homer. So, it's special. I mean, the way that he's able to make contact on baseball is God-given.


Okay so here we are and we're in October and just get ready, buckle up, buckle up people because it's coming in with the energy vibration to do with business and money. So it's like I've said this, I've gave the warning, I said September was going to be all about the karma and if you just stop and look at what exactly has happened, what's been disclosed, it's like it's a very very very very interesting time. So now that that energy has moved and now we're going to be looking at like the business structure, the financial structure, we're going to be looking at governments and we've got a lot going on from the 11th. Now we've got the Pluto and the Pluto is actually going to be going direct in Capricorn and I've talked to you about this, I've shared this with you that the Pluto over the last 20 years has been about slowly, slowly, slowly eroding everything to do with how business has been done, what's been happening with money about government. Now I'm getting a lot of disclosure after the 11th and the fact that we've got a very very strong like Mars energy in the Scorpio and here we go, what have we got going over here, going over ahead, yep there goes planes, choppers, over ahead as I'm doing October, classic, absolute classic and what time is it, yep eight o'clock, eight. So from the 12th through until the 31st intense, really really intense guys and that intensity is going to double up with this Pluto that is going direct in that Capricornian energy. Now we're up until the 12th, things are working out, trying to keep balance, trying to keep some sort of balance energy going. So as I said it's from the 1st to the 11th and then we've also got that energy just around the whole of the world placing to do with this balance and harmony but then we get a very strong lot of energy that's also going on here from the 5th to the 21st to do with thinking and to do with ideas but we've got this huge Leo vibration that comes in and hits and it hits to do with all relationships, so relationship between countries, people, etc. Now that's going to be very very strong from the 1st through until the 8th, things are going to become a lot more and the word that they keep on giving me here is like picky, like nitpicking, like trying to get to the bottom of things and that's from the 9th right through until the 31st. With all of the thought processes from the 22nd through until the 31st it is intense, really really intense energy and that's going to double up with a lot of the identity factor from the 24th through until the 31st. So we're getting this really strong Scorpio vibration that comes in starting on the 12th that will go through until the 31st then we get another Scorpio that's coming in from the 22nd through until the 31st and then we get another hit of the Scorpio from the 24th through until the 31st. Now I'm also seeing things firing up emotionally, the dates of the 8th, 9th, 10th, then I'm getting intensity, real intensity, see intensity and I'm picking that up around the 16th and the 17th with a lot of heated verbal exchanges around the 18th and the 19th, determination will abound on the 29th and the 30th. Now we do see here a very strong vibration and a lot of energy in regard to people or situations and it's saying I'm laying down the gauntlet and this is to do with creating a whole new cycle in the world because we once again it's talking about the ending of the cycle, the way that it's been but it's talking to me about people having to stand up, stand up, stand your ground, start using your voice. Now there are things that have been well it's been basically said that will be happening in October so I would be saying to a lot of people use your mobile phones or your cell phones if you're overseas, minimum amount of time, if you can switch it off during the day please excuse me switch it off because they've got us relying on these mobile phones right it's like and it's like they're attached to our to our hip you know the majority of time and there's something to do with communication, something to do with our communication you know our devices so just be aware of that right so I'm going to be like switching mine off for as much as I can especially and I'm getting around the first from the first through until like around the 11th okay all right what it is I don't know but from the first through until the 11th things are definitely definitely definitely moving so do not think that things are not moving now I'm going to highly highly highly recommend to everyone that are listening to this if you could please go to Rumble www.rumble.com and then put in Phil Godluschi Phil P-H-I-L surname Godluschi G-O-D-L-E-W-S-K-I and the show it's got 21 and it was on the 19th of September that that show that he actually came up he's got a lot of documents not just I've got this information I've got this intel documents and the documents are up on the screen do yourselves a favor and just sit in front of that screen and around about the first 10 minutes of he shows he just has music playing which drives me crazy so all you have to do is just like fall forward it right until you actually see him on the screen and then take it back to when you started to talk you are going to be blown away absolutely absolutely blown away and I know a lot of people have a lot of problems with Phil but I've actually followed Phil for quite a long period of time sometimes you know he gets me you know he gets to me but other times it's like yep okay so you're going to overlook some of the stuff that he talks about in regard to himself and about money and houses and everything else that he talks about but this intel on that that particular show phenomenal now I'm also bringing in here war like like people people going into some sort of battle is coming up for this month of October and it's about getting rid of burdens it's like we've got a burden we've got to unburden these people so we've got to get in and we've got to take some action to get this happening and again we've had this before rebirth so people you've all got to get in you've got to do work on yourselves you know for god's sake you know and people that haven't woken up by now look just you're just going to have to leave them go and you are just going to have to look after yourself and you go through the rebirth you do whatever it is that you need to do your health needs to be your number one priority not spending money on you know like going out you know clothing or whatever it's like your health your health because the healthier you are over the next few months the better your journey is going to be there's going to be a lot of heartache that's going to be coming in so we need to be aware of that and we're bringing in this month a whole lot of new ways of thinking as we can't release and let go of a lot that is no longer relevant in our lives hibernation is showing here but when we get that hibernation card like that it's like it's a choice it's a choice of something that you are going to choose to do yeah and listen to your gut feelings right if something doesn't feel right don't do it if it feels right do it get rid of your fear did you fear if you've got that fear it's like they've got you there is going to be a lot of our people a lot of our people and it's to do with the evil so evil anything evil that's been going on on the planet it's like that's it we're going to get hit with that and a lot of people are going to be hit you know like like hit for a sixer is the best way that i can describe this because they haven't wanted to look at this but even people who have looked at this we're now going to the next level right the next level of understanding of what's been going on there will be sorrow definitely definitely there will be sorrow but it's to push us to make up our minds in in regard to what direction do you want to take do you want to continue on your life that you've been living or are you like are you ready to suck it up and make the changes that you know that need to be made because we've got here again it showed up last month here it is again this month lies and truths that have been uncovered are going to surface so there we are guys and that's for the month of October and love you all those that are wanting to have um reading sessions with me on my the home page of my website tamara.com you've got the 220 that's for a basic one hour reading and if you're wanting anything more you just click on the tamara platform member okay so over and out and boy oh boy guys boy oh boy we're getting close we're getting very very close love you all bye


Okay, let's get started.  This is the third one, and always in the same spot. So it should be familiar to the people who came to the last one or two. Yeah, so I first wanna get started with thanking the sponsors, because basically if we didn't have the sponsors we wouldn't be able to do this. So starting with the solar sponsors. We have Ivan, who is a new sponsor for this year. We're very happy to have them on. They're a Finnish company, does data cloud stuff. Anybody from Ivan here? Okay, good, we got two folks back there. Great, thanks. Oh yeah, sorry, my name. I'm Chris, and I am one of the organizers here. We have quite a few actually in the audience, which we'll get to at the closing when we do the closing. But I'm also CEO and co-founder of Kinfolk. We're a Berlin-based company doing kind of, we're the kind of cloud, you know, cloud native Linux company doing all open source Kubernetes type stuff. Then we have Facebook of course, or the third straight year. Thanks so much for, we have a lot of Facebook people. How many people are from Facebook? 28, okay, that's like 10%. Well, yeah, much thanks for their support, yeah. And then we have a new sponsor, Packet. Packet does bare metal hosting. So it's kind of like, you know, slim down AWS kind of thing, but you can provision bare metal. So it's really good for folks who are looking for a lot of performance and, you know, wants to do things, you know, take control. Then we have the lunar sponsors, Pantheon. It's been here for the third straight year. I think David and some of his colleagues are here. Can you raise your hands? Okay, great, yes. And then we have, of course, Red Hat. How many Red Hatters do we have? Anybody know the number? No, it's a lot of Red Hat folks. What's that, Vincent? Less than Facebook. Okay, less than Facebook. Okay, good. And then we have the terrestrial sponsors, Grafana Labs. There's a couple of Grafana people here, right? Right here in the front, yeah, David. First speaker, right, so stick around. And then we have Microsoft. Anyone from Microsoft here? I know we have people coming if they're not here already. Okay, they'll come later. Yeah, thanks so much for the sponsorship. And I want to point out the sponsorships also this year were enabled us to offer a lot more diversity tickets and we are actually, for the first time, able to sponsor travel and accommodation. So that was really great. Okay, we're gonna go through the basics and I'll hand it over to Lexi for this. Hi, I'm Lexi. I'm the head of events at Kinvolk. And yeah, I'll take you through the basics. Anybody wearing a gray shirt is basically staff. So if you have any questions, you could just ask them, toilet locations. We have three. One is a little bit of, is that me? Or, no, okay, sorry. Yeah, wiki wiki. Anyway, sorry. So there's one bathroom when you first walk in. There's another one on the stairs. And then there's another one.  So you have another option. So there's three. Watch out for cables, obviously. Everybody should know that, but still worth the mention. And the hack space. We have international plugs at some of the tables. So just be mindful. And USB plugs, of course. Okay, the social event is tonight. It's at MinehouseMZ, which we forgot to mention, but still it's a really fun hotspot and it's from seven PM to midnight. We should be ending things here at like six. So just hang around. There's beer downstairs and there's beverages. And then we'll actually meet in the gallery at 6.45 and then walk over together. Just so we don't overwhelm the venue because we're only supposed to be there at seven. There's vegetarian vegan food in the, I guess the lower level. A buffet. And then there's an open bar till midnight. And after that, we will, there will be more people coming because they kind of opened the doors up, but I mean, last year we really had a good time. So if you want to stay till midnight, you could, or past midnight, you could stay. And everything is enabled because of our sponsors, Grafana Labs, Packet and KinVolk. Food and drinks. So beverages in the greens are sponsored by Facebook for the second year in a row. So thank you very much. I think that's also why there's a lot of people missing right now because they're getting their coffee. Cold drinks are located in the gallery. There's two fridges. And please put the bottles back in the bins.  And the food trucks will be available for lunch on Friday and Saturday. And it's only cash. So please bring your euros. And code of conduct. So we want to make sure that ASG is a safe and inviting place for everyone. There's a link right here for the code of conduct. Please read it if you have not yet. The contact numbers for the code of conduct. Oh, I just heard myself. For the code of conduct, people are there. I'm one of them. And then Lars, who is not here yet. Yeah, thank you for turning me down. Who's not here yet is the other individual. But if you have any issues, please also either find me or go to the registration if we're here. If we're at the venue, please just call me or Lars. And that's it for me. Okay. And so otherwise we have on Sunday, after the presentation days, we have the Hackfest Day. David, where are you? He's not here yet. He has a talk today, so I think he's organizing that. But yeah. Downstairs, he's the main organizer for that. You should have gotten an email about that earlier about signing up for that. If you still want to have stuff, we have whiteboards downstairs where you can put your ideas there. So we want to get groups together for Sunday. Last year was a lot of fun. It's in the gallery, which is basically the lounge, hacker lounge. And yeah. And food will be provided. Probably simple pizza, because that's classic hacker food. I think there's options over there. Yeah. Also. Yeah. We can also get vegan pizza if it's pizza. So lighting talks, there are still slots open. That's today at the end of the day. Tilo, who is sitting here pointing the camera at me, is organizing that that you can also sign up for downstairs on the whiteboards. And so right now we have four slots. We can take probably four more at least. So if you have an idea for a lighting talk, just grab that. Note that. And I just want to remind everybody, so you may have noticed on the way here, today is like global climate strikes. So we kind of unfortunately collided with them, because I know some people have mentioned that they would have liked to have taken part in that a little bit more. I just want to say that, if you did travel here, you can offset your, you can do CO2 offset for your travel. We'd recommend that. And also take public transportation by electric transport while you're in Berlin. If you can. And things we're doing, if you notice, I think we're pretty, we try to be pretty darn good here. We only have reusable beverage bottles. We don't get any of the, we only get reusable plastics and glass. We're just one of the reasons we're going for the vegetarian and vegan options at the social event. And we have paper badges instead of plastic. And you know, if you have further suggestions, we're happy to hear those. So yeah, that's it. Thank you all for coming. The first talk will start in just a second. Any questions before I get off here? No? Okay. Oh, we do have one question. That'll be downstairs in the gallery. So, oh, I should also mention, so because the cage room, we've mentioned the cage room is where the other talks are taking place. That's actually on the opposite. So last year we had it up in the upstairs. This year it's at the other end of the gallery. So if you, when you came in, you probably took a left to go up these stairs, but if you take a right, that's where you enter the gallery or the, basically the hacker lounge. And only if you keep walking through the hacker lounge, you will come to the cage room. The cage room is the one with Angela Merkel's picture on the wall, you know, kind of a mural. And so that's where the other talks are taking place. And so in that gallery, where you're walking to the other room, that's where the whiteboards will be for this. Okay. Any other questions? Okay, so thanks everybody and we'll kick it off. I think David has the first talk in about five minutes, four or five minutes. Okay, thanks. Thanks for coming.


Now we are going to see how to see the analytics for your course, in the analytics you can see the enrollment and assignment details of students. Now we are going to see how to use this analytics tab. First login with your course admin ID then you would be in the course dashboard. Already you are familiar with the course dashboard I think you may have start working on it. So in this here there is a tab analytics, go to the tab, when you click this analytics tab you will be able to see the labels on student, student progress and enrollment assessment details here. Since it is a whole course we have run the analytics already. If you are on a new course you will be seeing the steps alone, labels on student, student progress and enrollment assessment. For this you have to update the statistics. You can either update all statistics or you can update the statistics whichever you want. Just give update statistics. When you are giving the update statistics you will be seeing the statistics running now. You can see a tab cancer statistic calculation. It will take some time to calculate the statistics. When it get updated you will be seeing the graph whichever we have been seen before. In the enrollment assessment details you can able to see the enrollment details of students. How many of them have enrolled previously and currently and total enrollment status. For this course there is 3612. And once you have opened the assignments you will be able to seeing this details. This is the assignment ID which will be displayed on the top of the assignment in your course. This will be the number of students completed the assignment. This will be the average score of the students which is displayed here. After running the analytics after sometime you can refresh the page you will be getting these details. In the student progress you can able to see the completed status of assignment. Here you can see 567 members has completed assignment 1. That is the assignment ID is seen. You can see that in this graph assignment 1 567 members have been completed. In every assignment this will be showing your statistics. This will be helpful for you. For units it will be displayed in this color and for assignments it will be in blue color. You can see the numbers here and enrollment numbers in this tab. From the first students tab you will be able to get all these details. Secondly the watch time. Watch time is here in this assignment. In this course you can click this watch time. You will be able to see this page. Here you can select the lessons in this drop down. There are three lessons. I am selecting the first lesson basics. You will be seeing the statistics. This x-axis displays the seconds and y-axis displays the number of students watching each seconds. Here you can see in 600 seconds of the first video in this lesson 594 students have watched this up to 600. You can see the statistics is going lesser and lesser. This will be able to analyze you why the students are not watching the video, how many of them are watching, how many seconds they are watching. You can see that in this blue color line it is increasing and at the end it is decreasing. You can be able to see the watch time and you can analyze why the students are not watching the video after 600, why it is any problem. It will be useful for you to get the statistics. Then in the questions, when you go to the questions tab, you will be able to get this page. Here you can see all the questions, whichever you have created in the assignments. The average score of assignments, how many of them attempted that question in the assignment. In the assignment 10, question number 1 is attempted by 159 students. The average score of this is 0.92 for these questions. You can see how many of them pick the choice 1, choice 2 or choice 3. How many of them have picked? If choice 1 is the wrong answer, if more than 200 students or 300 students have selected choice 1, you can analyze why they are selecting the wrong choice. So, you can be able to guide them regarding this. So, it will be useful for you. It will give all the details for each and every question, whichever you have created in the assignments. You can also have a look at all the tabs in the analytics and they are under developing stage. Some may work and some may not. So, please have a look at all the tabs. These three tabs which I have explained here will be useful for you.


What's going on? Welcome back to the channel Jordan from modern day muscle. We're out here in Lakeland getting some uh some vinyl work done. We've got garage driven over there, Henry over there, Sid and Indyster over there. He's doing all the vinyl work um I'm not gonna I'm not gonna spoil it for y'all um for Paul but um I'm getting something on my car that was always needed and I'm finally getting it on there so let's see uh how the day goes going on guys modern day muscle man recording on record right now record and record that's how we're gonna do it huh? Yeah, we're gonna go right there. You guys are doing it finally. Clean. It's done. Look at that. Still perfectly in the car. This is the finished product guys. It's amazing. What do you think Paul? I'm in love man. All right guys this looks great. I wish I had a drone. Yeah I wish I had a drone because then you guys would be able to really sit but like look at that. Ruth is not playing no games no more. All right so yeah we got a couple vinyl works done. Paul got his which that flag looks amazing. I finally got the YouTube sticker on there which I'm happy with. It looks it makes the car look so much better. I can see it from a distance. This video is done my name is Jordan this is modern day muscle um if this is your first time to the channel please like this video and also subscribe as well and hit the bell notification icon on modern day muscle on uh no a modern day underscore muscle on instagram it's going to pop up on the left or the right hand side of the screen. I'll catch you in the next video guys.


Good afternoon. Hi everyone and welcome. My name is Jason. I'm a librarian at San Francisco Public Library Wherever you're tuning in from I'm so happy you're here with us Go ahead and pop in the chat where you're tuning in from we love knowing where our audience Audiences are we're gonna start off with the little trailer of what we're doing a little video Awesome. So today's book project is called exquisite corpse fold It is the final project of our three-part series with our friends from book arts roadshow and our trusty friends will share the supply list in the chat This is part of our make-do program series Your place for craft and maker programs for school-age kids and their families So check out our website for calendar listings and that link will be in the chat also It'll have downloadable activity sheets book lists and more And before we begin we'd like to start off with the land acknowledgment We are on the unceded ancestral homeland of the Ramatush alone II who are the original inhabitants of the San Francisco Peninsula and continue to live work and play here today as The indigenous stewards of this land in an accordance with their traditions the Ramatush alone I have never ceded lost nor forgotten their Responsibilities as the caretakers of this place as well as for all peoples who reside in their traditional territory We wish to pay our respects by acknowledging the ancestors elders and relatives of the Ramatush community And by affirming their sovereign rights as first peoples We'd like to give a huge thanks to the friends of SFPL for their generous support of this special series So we can't do this without them along with all our other programs Without further ado, let me welcome book arts road show which was co-founded by Cheryl Ball and CK at Amura And they provide book arts instruction and hands-on learning experiences for children teens and grown-ups Take it away books art road show Hi, thanks so much Jason for the nice warm welcome and thank you to San Francisco Public Library for having us back for this third of three The third part of a three-part series of book making. We just want to let everybody know that this Bookmaking session is being recorded. So if you're watching it live on YouTube right now, that's great But let your friends know that they can go to the YouTube channel for San Francisco Center for the book and watch it later on And so can you San Francisco Public Library. Oh, I'm sorry. What did I say? Did I say I don't even know what I said That's okay San Francisco Public Library. Oh San Francisco Public Library So anyways, thank you so much for having us again, we're gonna be doing an exquisite corpse book And so we're gonna show you some examples of what an exquisite corpse book is and then we're going to Show you The tools that you need the supplies that you'll need and then we'll get started on making the book So here's a little example of an exquisite corpse book. So it's a multiple Section book where you can have illustrations and You can turn each section of the page to change the illustration to something else And You can also use it not just for Illustrations, but you can also use it in several different ways. So Let's see so another way you can use it is As a learning tool for constructing words So we have the word dot here. We change the last letter to a G Becomes dog. If you change the last letter to an N becomes dawn dog dig Can So you can use it for word learning word learning letter learning and you can also use it as a flash card tool for Mathematical equations so you can go ahead and change the numbers change the mathematical symbols and That's great to use as a flash card tool as well for older kids instead of putting simple numbers or The spelling a word you can actually use it to build sentences or even stories So keep those things in mind That of different ways that you can use These exquisite corpse books So, let's see. Oh I forgot to mention a little bit about us. We're the book arts roadshow and Before COVID We used to go around to different locations public libraries schools museums in person and teach workshops on how to make books but Since COVID started we've been doing it at all of our workshops online And we really appreciate that terms of school public library has invited us to do another series Just so that you know the previous workshops that we did are also on the San Francisco public libraries YouTube page So if you go to the YouTube page and you search for book arts roadshow or make and do You'll see all the previous workshops that we did there, too So without further ado Cheryl would you like to show everybody the tools that they'll need for sure look let me Switch to my overhead camera and then you can see what tools So I just have a stapler a pair of scissors a Sharpie it doesn't have to be a sharpie. It could be any black marker a Pencil a Wooden spoon or you could even use to use a regular metal spoon whatever you have at home The spoon is used in place of Bone folders which these are them but these are not necessary and We ask for a little tiny what it could be any size ruler really so a ruler and then you'll need five sheets of paper and One piece of card stock so That's what you need five sheets five and three quarters by six and Then six by six, but you can use any size. We're just using this size for this demonstration alright, so CK is gonna tell us how to do this and I will be the hands on the camera Thanks for sharing all the tools with us So first thing we're going to do is we're gonna take actually instead of five sheets of paper We're gonna do this with four. It's just easier to fold so we're gonna take Four sheets of paper not your card stock, but your actual four sheets of paper And you're gonna jog them together so that they're all lined up Stacked on top of each other nice and neatly and because it's a six by six square It doesn't matter which direction you fold it, but we're gonna be folding it in half So you're gonna match up your corners after you've got all your papers jogged up on top of each other you're gonna fold it in half and Match up your corners as best you can and then go ahead and fold it in half and After you fold it in half you're gonna make a little dense on the crease side and you then you're gonna go ahead and Smooth it out with your finger to the top and bottom and then take your spoon and Press down hard on the crease to make the crease very sharp And then got basically what's called a signature of pages That's ready to For the next step You're also gonna take your cover, which is the piece of card stock and you're gonna fold it in half the same way so you're gonna match up the corners and Then Once you've got the corners matched up go ahead and press down on the fold side and put your finger up to the top and slide it down to the bottom and then grab your spoon and Press down with your spoon to make the crease really sharp great Now you've got your cover and then you've got your signature of four pages folded in half which actually turned into eight pages And then What we're gonna do is we're gonna Take one of the sheets of the pages just one at a time. So take one of the sheets and Your ruler and your pencil and the first thing you're going to do is you're going to turn your Piece of paper so that the fold is horizontal Great and then we're gonna take the ruler and we're gonna place the ruler parallel to the fold that's already on the piece of paper and Starting at one edge of the paper. We're going to draw Let's see kind of slide your ruler up toward the top of the paper just like all the way to the top edge of the paper. Let's see, like this, like take your ruler and then slide it all the way up to the top edge of the paper and then we're going to go ahead and mark at two inches with your ruler and at four inches. And then you're going to mark at the bottom edge of the paper two inches and four inches like that. So you've got one mark. I'm going to do it with a pen. You can see where the marks are. One, two, three, four. So we're just going to have four marks. So we've got a fold right here. And there you've got a mark up here a mark up here a mark down here and a mark down here. So this was that two inches and four inches and two inches and four inches. And then what we're going to do is we're going to play connect the dots. So now we're going to get the pencil and we're going to connect the mark on the top with a mark on the bottom. And then also do it again from the top to the bottom. So then you have something that looks like that we have a line here and a line here in your fold goes across the middle of the page. Great. So we're going to do the same thing to the other three sheets of paper. You can open up your page your paper and then make a mark at the top edge at two inches and four inches. And then at the bottom two inches. And four inches, two inches, four inches again. Two inches and four inches, two inches and four inches. And then we're going to play connect the dots and connect them from the top to the bottom with the pencil that page. Number two, we'll get to the third one. You probably already have it by now, but I'm going to go ahead and call out the instructions anyway. So you're going to place your ruler parallel to the fold market at two inches and four inches on the top and then on the bottom, we're going to market at two inches and four inches and then connect the dots with your pencil almost it wasn't an earthquake. It was just me shaking my computer. Don't worry. Okay, and so you have that and then we'll do it on the fourth sheet of paper. Now, as I mentioned before, you could use more pages, but just because it's easier to fold your pages, we're just going to use four instead of five today. Number four, same way. So now we have, it's hard to see on mine, but we basically have my lines with a sharpie pen. So they're easier to see on the camera. So each of the pages basically should have lines like that now. Great. So now, a lot of measuring in this one. Now we're going to take our ruler and turn our page this way so that the lines are going horizontal. Take our ruler again, and then go ahead and put the ruler on one of those lines, then mark the lines. Let's see putting the ruler on the starting from the left edge. I'm marking it at two inches. Oh, I'm sorry, I'm marking it at one inch, two inch, four inches, and five inches. And if you notice, I skipped three because the paper is already creased on where the three inch mark is, so we don't really need one there. But what we do have, and I went ahead and I'm going to put my marks in sharpie. It's hard to see on the screen. Great. So we've got these little dots here now. Okay, this is at one inch, two inch, four inches and five inches. And we're going to do that to the bottom line as well. You know, Cheryl and I are doing ours in marker, but you should be doing yours in pencil. We're just doing it in markers so that you can see, see the marks on the screen. Yes, I actually prefer to do mine in pencil usually. So now the same set of dots. We're not playing connect the dots this time. But we're going to put this one aside and we're going to do the same set of dots on all three other sheets. So again, you're going to get your next piece, and you're going to measure it from the left, going to measure it at the one inch mark, the two inch mark, the four inch mark, the five inch mark on both lines. So one, two, four, five, skipping three, because we don't need three inches. Again, now that you're getting the hang of it, we'll go to page number three and do the same thing and mark those dots on those lines. So you can actually make the dots really light because in the end, probably going to just erase them. They're just markers for the next step. So basically everything we're doing right now is in preparation for the drawing version of the exquisite course. So now you've got four sheets of paper that have all these dots on them. So what we're going to do is we're going to actually start drawing. So with your marker, looking for my marker. So with your marker, what you're going to envision is that the top section above the fold up here, the top section above the fold is where the head goes. You can envision something like this little happy son with a stick body. The head is above on this top section here above the top line. The body is the middle section, and the legs are going to be the bottom section. But the reason why we have those dots there is because the dots are where all the body parts connect to each other. So in this case, in this sample, the dots would show up here and here and here and here in the original drawing. So that's where the head connects to the body and where the body connects to where the legs show up. So Cheryl's saying to draw hers. You can use our samples if you want to or you can. I'll show while Cheryl's starting to draw hers. And if you're trying to get some, I'm just going to show you some other little ideas. There's a music note person that has music notes all over. Just to give you a few ideas. And we're not going to draw all of them right now we're going to draw a few of them. Just so you can get an idea. And then after this video is over, then you can go ahead and draw the rest of them yourself. So here's another one that's actually a plant that has a face on the top, a body in the middle and a pot for the bottom. Here's some sort of strange insect with web feet and wings. So maybe it's not an insect. I'm not sure where that character is from, but the head is up here, the neck connects to the body at those two dots, and the legs connect to the rest of the character on the bottom. And again, just for some more ideas. There's a person's head on that body. But then we turn the page and now there's like something that looks like an insect and stick feet. Another little sun. Not sure what this other character is going to be looks like maybe it's some kind of crazy chicken. But it has like a fish mermaid tail on it. So this was all just to get help give you some ideas of things that you might want to draw. Some other show what this last one's going to be feet. So there's some running feet, but there's some kind of like little bees wings on that one. That's some ideas shows doing a great job there drawing. And then if you don't feel like drawing right now, then you can just watch the rest of this video you can think about what to draw and you can draw later on. Great. So let's see where we are now so shows got her drawings there. And we have some pre drawn drawings can't have handy to. So she's going to go ahead and use the pre drawn drawings on there. So, at this point, if you want to catch up and draw your drawings before watching the rest of this video just pause the video and then start playing it again after you're done with all your drawings. Otherwise, we're going to go ahead and move forward with the next steps. The next steps would be is that you would take all your drawings and stack them up on top of each other. And then you're going to fold them in half and use your spoon to make sure that the creases really sharp. And then what we're going to do is we're going to insert the pages into the cover. Remember the cover. There's a piece of cover stuff that we folded in half in the beginning. So we're going to insert the little bit bigger than you can hear the difference in the paper. So basically yes cover stock is really thicker paper is what cover stock is. And then we're going to insert the pages in there. So and they should fit in nicely because the pages and the cover all the same size. And then we're going to open the to the center section. And then we're going to go down the center page there. And what we're going to do. In fact, Cheryl, if you want to just draw a little dot or a line where the sections are the sections. Yeah, just on the center fold. Oh, yeah. There's a little where those lines are she's trying a little dot or a line right in the center where those right on that center line, we're on the center fold, we're just trying to line a little dot right on there. So that is basically the dot that's making the the fold divided into three equal parts. So above the top dot, we're going to just draw a little line where a staple is going to end up going. The staple is going to go roughly in the middle of that top section. Perfect. And then in the middle section or the body section, we're going to draw a little line there. That's approximately where another staple is going to go. So we're just drawing them so you can see approximately where the staples are going to go on the pages. So one staple per section so you're going to have one staple in the top section one staple in the middle section and one staple in the bottom section ultimately. So now you can grab your stapler. And then slip your stapler in and try to keep all your pages all lined up nicely together. And you're going to go to that top section and put one staple right there in where you drew the little staple line. And it's going to go right onto on that crease.  It's hard to see but there's actually a staple in the middle of that now. So then we're going to go to the middle section where you drew another line for where the staples going to go. And we're going to go ahead and put a staple in that section as well. One staple right there and another staple right there in the middle. And then we're going to go down to the bottom or the leg section, and then go ahead and put one last staple in the bottom. Now, we've got another staple down at the bottom. Good job. Now what we're going to do is we're going to close the book again. And use your spoon to sharpen the crease, because now that we've added staples to the crease the staple the it's bunching up a little bit, it's swelling a little bit. So we're going to flatten that out with a spoon. And then you're going to just take the cover only and open the cover. And then you're actually going to open the. You're going to see you're going to open the first 123 four pages. Yeah, so you have your cover that you just opened, and then you're taking the first four pages. And you're going to open to where your lines are. And basically you've got half the book open right now you've got the cover and the four pages. You should be in the middle, you should be in back in the middle again. What you're going to do is you're going to cut on the lines, but you're not going to cut the cover, you're only going to cut the four sheets of paper on that line, but not the cover. You're going to cut it just until the center fold. So Cheryl has her scissors there but she is not cutting through the cover. See how I'm holding it so the cover is away from the pages, the covers away the cover is not inside the scissors, and she's cutting just the pages up until that center crease. And then she's stopping, and she gets to the center crease. The point of my scissors are stopping. So then you'll have the separation of your pages. And then she's going to cut on the other line.  Okay, cutting, I'm trying to cut as straight as I can just moving the scissors forward in the straight line. There we go. Great. Perfect. Great job. Okay, now we're going to turn the book upside down and we're going to go to the other side. And we're going to cut the other four pages, and we're going to make sure not to cut on the back of the cover is away. And I've got my pages. I'm just cutting on the line make sure your fingers are out of the way to so you don't cut your fingers. You're going to cut all the way until that center fold with any and you didn't cut the cover. So now you have your covers are intact. Your cover is still intact. But your pages are all now cut into three sections. Everybody got that. Right. So now once again you're going to fold it.  Use your spoon, handy spoon, and then go ahead and smash that crease down really well. And now on the cover if you want to write a title like exquisite corpse book or something on the cover. You could do that. Or any other title that you can think of. Do you want to show off the pages of your book. Sure. So here's a rocket ship. But, oh my goodness, the rocket ship can turn into something else. What is that for. It can turn into a squid. And then here's my caterpillar, which can turn into a caterpillar and a cookie. And here's my carrot, which can turn into kind of a robot carrot with bunny feet. And the abilities are endless because there's my rabbit there's a cacti the cacti can turn into part gingerbread body. Gingerbread cacti. There you go. Now that you know how to assemble or how to make an exquisite corpse book. Remember the ideas that we showed at the beginning where you can actually use it to go words. You can use it as a book for math problems. Math problems. You can use it to put a word on each page to make sentences that change as you flip the pages. And you can use it for stories as well. But in addition to that Cheryl's got another thing to tell you about the exquisite corpse books. I'm going to keep this paper here because I'll explain what this is for. So the exquisite corpse book actually started back in 1925. There were surrealist artists who got together, and they would just make up games and one of the games that they used to do is like they would each take a turn and tell a story like Cheryl was saying, and you could put different sentences on each section different words. So they would do that to create stories. Well then somebody decided hey what if I, and they would have all these marks.   And they would pass us along to all these people to fill all these different parts and then you truly truly had like an exquisite exquisite corpse book because they're all corpses their bodies, and they were totally fantastical. So that's something you can do with your friends as well. And then one other modification that you can make to the books to today we use the stapler. Just a little desktop stapler. If you wanted to make a larger book, a larger version of this, there's a couple ways to do it. One of them is to something like this, this is a saddle stapler. You've got access to one of these these are great this allows you to make the pages bigger than the size that we did today.  And that allows you to make larger books. Oh, and she's showing how you can use the standard stapler. Yeah, some of these open up like this flat. So then what you could do is you can take a, let me see. You can take a phone book and, and here's the center, you can just take the stapler and push it in and then what you'll do is you'll take the back of the paper and push the staples down. And then there's a piece to do it. I'm sure you've seen teachers using this to staple things on the board so and then Cheryl's going to show you another way to do it. So another way to do it is not to use any stapler or staples at all and it's the other way to is to sew the pages in. So you would basically do all the same steps that we did today, except for this one here. The pages are actually sewn into each of the three sections of the book with a simple stitch to hold the pages inside the cover. So that's another way you can do it as well. Cheryl, quick question. So I think I believe the video to sew that that's a three hole pamphlet stitch is on the San Francisco public libraries. Oh, yes, because we taught that one before. Yes. So if you're trying to figure out how to sew the book, go ahead and look for, look through the other make and do workshops that the book arts roadshow that's us did, and you'll learn how to do this sewing stitch that you can combine with the exquisite corpse book. Yeah, I think that's it. Congratulations, you just made an exquisite corpse book with that. Show your friends how to make them and also follow the same Cisco public library on social media. And I believe the hashtag that you can post pictures to is hashtag make and do SFPL. So if you make your books, take a photo of them post them, then the folks at San Francisco public library and us, we can see them. Also follow us, the book arts roadshow on our Instagram, which is at book arts roadshow. One more time. This session has been recorded. And so you can find this session and all the other sessions that we did. All of our other book making workshops that we did with the San Francisco public library on the San Francisco public library YouTube channel. And I do want to say thanks again to the friends of the San Francisco public library for making this and the other workshops possible. Without them, we just, we wouldn't be here. We appreciate being invited somewhere else when I just have to give credit to the drawings. CK them all. So thank you everybody for joining us today. It was wonderful to see you have a safe holiday season, and we're looking forward to seeing you in person sometime in the future. Bye now. We just keep waving because we don't know when we're getting cut off.


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