Welcome to East to East to East to East to East. Hello, hello, hello. Um, as someone who tells everybody their secrets, I'm very excited for the next talk. So, um, we've got our next speaker, um, Pedro, who's going to be speaking. Um, their talk will be bring your own secrets but shout them out loud.
How to bring privacy to a public blockchain. So, welcome Pedro. Hello. Just going to grab the clicker here. Sorry, I just just arrived yesterday.
I was like, nice town. Yeah, I love this. Uh, glad to be here. Um, yeah, I'm just going to tell you who you are, right? Okay, that's first thing.
Right. Right. Right here. You are now um a note. Okay.
Maybe you're like, "Yeah, but I'll try again." Okay. You you are um you are a a transit state in spacetime. Does that make bit more sense? Did I I start not farewell right?
It's not not a great start. Um yeah, I don't know what I'm doing here. Sorry. Yeah, thanks for attending. Okay, I just just gonna start from the beginning.
Okay, but yeah. Yeah, let's forget about all of this. Uh let's let's let's go start with an actual agenda to first first uh gonna talk about UAXOs. Okay. Um and then I'm gonna talk about like who you are.
Uh so hopefully that will make a bit more sense then. And then uh about this thing that we're trying all to build like this world's most expensive time stamp clock machine whatever and then and then yeah then finally about like keeping these secrets that I was talking about. Um so yeah maybe that will make more sense. I don't know. But like why?
Yeah. Why UTXOS? Like we is a new tech for thing, right? It's like let's just talk about that a little bit. Um see Alice, she's holding a 20 bill.
So I guess in Amsterdam that that's enough for a coffee for a coffee or something, you know. Um and basically there's this Bob. It's not very happy guy, I guess. Um, and then Alice will pay Bob 5 again just for a bottle of water, you know, and and basically there's a transaction that is going to be spent that Alice had and that um was not spent. So basically she's saying, "Yeah, I'm gonna spend this gonna destroy this 20 euro bill and I'm gonna create 5 bill that will go to this person."
And they're like, "Uh, well, where's this the change?" Well, the change is another transaction that goes back. Actually, two transactions that go back uh a 10 and a 5 bill. So this is uh basically all of these bills are unspent transactions. So you probably know this already because this is a fundamental of Bitcoin and that's why Bitcoin is a UTXO uh based blockchain.
So this 5 bill is thinking who who who is who is it? Who who am I? And this is where I want to want to come to. Um this is just an incoming transaction that was not spent yet just waiting to be spent. And my goal here is to tell you that you are also an an incoming transaction that is waiting to be spent.
And they're like, what what does this had to do with Aztec? But I'm going to get I'm going to go there. So first of all, why did we move away from this? Right? Seems okay.
It seems like imitates it imit imitates cash very well. And that's why Bitcoin white paper was called peer-to-peer electronic cash uh system. Well, sequencing sucks, right? That's the first thing. Like there's an order and order really sucks when you need to do things.
And this is very common in Aztec where you actually have uh public and private transactions and you just can't assume something has happened just because it has happened in in private. That's that's a bit more complicated than that because you don't actually know when something happened. Just know that it did and you also don't know where and how or which contract anything. Um and then yeah Turing is also not happy because yeah you just you can say oh I can hold this many transactions and that's it. Then at some point when it runs out I just cut a new block.
But if you need programmability, that's bit harder to do. And then yeah, UX is great, right? I don't know if you ever tried to use Bitcoin like the actual network, it doesn't doesn't Yeah, it's not a great experience, right? Especially if you go into lightning network. So gas, right?
There's this guy that came in with this idea of gas. What is gas? And I I'll try to explain what I mean this time. And but basically Gaz is how you define uh all the operations in your transaction. So you can actually have some programmability.
You can say yeah every every um operation has a cost. And so I'm just going to sum up all of the those costs and then when I reach a certain amount and I'll say okay I can't hold more cost. I can't hold more gas. I can't spend more gas. Then you cut a new block.
So this is what time looks like, right? So if we have a gas powered virtual machine that works differently from UTXO machine, you have block N which has an world state as you know it, as everyone knows it. There's a consensus mechanism that makes sure that everyone knows what the world state is at a certain point in time. That's why it's a very expensive time stamp machine. And then you just have some high gas shitcoin transaction like someone is buying I don't know some kind of memecoin or whatever and just paying paying a ton of gas and that goes into the world state and generates a new state.
And so once you say okay I just I can I can I can just process more gas. Sorry. Then you cut a new block. You create a new block. you create a new state and everyone will agree on that state.
Okay, so I'm I'm just explaining Ethereum basically. That's it. Why is this a problem now? Like hasn't hasn't this been working well so far? Yeah, but also no.
Because privacy that's that's why if you need to agree on every transaction that goes into a state so you can calculate the next state then everyone needs to know what goes into each state right so that's why blockchain is useless right basically if if you scream every single transaction for everyone to to hear so they can calculate what's the next state will be then everyone needs to know what's next what's every transaction And how's that useful? It's not, right? That doesn't make any sense. So, privacy is actually a big deal, right? I mean, it's there's this little book that I guess no one has heard about, the declaration of the human rights that says that no one can actually interfere with your correspondence and family and home and just privacy in general, you know.
So, that's just a human right. I'm not talking about something like tin hat, the tin foil hat stuff, you know. So if we go back to basics and talk go talk and ask who who are we who are you well it kind of depends right because like if first of all you need to define who are you in terms of time the present what is present but now that you gave up because we also don't have a ton of time um you you have to consider the past in order to consider the existence of the presence present there's no present actually present present is just a past that has happened an infinous amount of time just before now now right so it's very hard to define present is something that doesn't really exist if you try to define future you can actually pick a future that you can reason about um but yeah I mean you still need to agree on what is time what I mean you can define something in the future but we need to agree on a clock. You can say 10:39 there's a clock I can go through there. You all can go through there and that's fine actually.
And then we we need to understand that we are social beings like nothing stops you from using another kind of clock. That's fine. You just won't really work with me. Right? So actually I think it was here in Amsterdam that uh the clocks were just you using a different way to count time.
So you just would just come here come here and just align yourself with the city and just use a different way of counting time and that's no problem right as long as people agree that's fine. Then the English came with the green green meantime and just I guess used this a system that works everywhere. So you are you are a a new Dexo and yeah actually yeah I have a um slide about that like yeah before 9 1909 you you actually your pocket watches wasn't valid anymore when you arrived here. Um the tic tac the clock is just a it's just a time stamp machine that we agree on. So wait I am a UDXO now you are right and because like physics says that you do have a deterministic position velocity uh yeah you can represent yourself in UTX.
If you choose a time stamp to measure it, you can say I'm here now as long as we agree where where is now. Biologists also say that yeah, your blood pressure is whatever you're burning this amount of calories. Uh same thing you can say, yeah, I can choose a time stamp to say at this point in time my blood pressure is something like that. I don't know that. You probably don't know that as well.
That's private, right? But you're still unity exo as long as you can represent yourself in time in biology terms. What I say because I'm also I'm not uh yeah your your brain holds a ton of memories as well. But and just the same I don't know what you're thinking about. I don't know what memories you have.
You also don't know which memories you have. So I can represent myself and you can represent yourself in UTXO terms if you choose a time stamp. You don't know what your next thought is going to be, right? So finally, what the hell is this? This has this has to do with elastic, right?
And that's it. There's a decoupling between what is state and what is uh a transaction. You can define yourself as an UTXO and no one needs to know everything about yourself. So has to be blockchain. So basically going back to the beginning, you are just like a train transient state in spacetime.
I don't know everything about you and I don't know I don't need to know. I just need to know what's the outcome of what you're thinking. What's the outcome of your blood pressure? What's the outcome of uh your position in this room? I don't need to know anything else.
I just need to know what is what has become of you. So yeah, how do we make a better time time stamp machine? Um, so yeah, going to talk about UXO UTXOs like you just we kicked out UTXOs and then they come back with us like so why why is this again and again? your representation yourself. It just can't be kept as a leaf in a miracle tree.
We we want more. We just want the tree to be true without knowing what's come what's coming into the tree. So we thought Ethereum is not good enough. Again, you are encoded with your secrets in real life and you need to advance state. You need to shout because everyone needs to know what the next state will be so you can agree on a time step.
No leaking, right? If you leak, then your prophecy is gone. Um, here's a case study for a game called game on asset called Frogling. Um, it's like a kind of magic the gathering mechanics. You can attack and whatever.
Um, and all the stats are kept private private even when you're fighting. How do you prove that your frogling survived an attack without revealing what current health? Right? In Ethereum, you would have to know what is the amount of the attack. But in real life, if you're fighting someone, there is no stat on top of you.
It's not you're not screaming, you're not shouting to everyone in Ethereum to know what's your next what's your attack um I don't know like um rate or something like that. You don't you don't know. That's not how real life works. So that's not how blockchain should work, right? So if you have an attacking player, an ephemeral attacker, you just encrypt that to an ephemeral defender and which makes the change of state in private and then goes back and encrypts itself back to the attacker and so on so forth.
And so this is some pseudo code of that. It's actually quite old. We don't use these macros anymore. But yeah, I guess that's um that's a bit a bit of a of an idea. Just encrypt your just encrypt your attack to the other person and just shout that in private.
Shout that in private, right? So yeah, keep your secrets. You cannot forget privacy. You can't offload privacy and you have to do your own privacy. You you can't hire someone to just do it for you.
So everyone is like we can do privacy. No, you can't. If you hand it to someone else, you can't, right? Sorry, you have to do it yourself. Actually, how do how do we even on board the next billion if we care about that?
If we're just making everything public, like are we mad? Are we mad? Like, what are we doing here? We're just like giving everything. Yeah, you can't trust anyone, right?
Your your node will leak. Um everything will dig. So yeah, if you want something done, please do it yourself. And that's that's what we are uh doing with Aztec. Um yeah, that's it.
Thanks for attending my TED talk. Okay, I'm joking. And here are some things about me. Uh oh, I don't use Telegram anymore. Sorry.
Yeah, yeah, yeah. Say all, please. Um that's it. Thank you for attending. [Applause]
Automatic transcript — names and jargon may be misspelled.