Will Quantum End "Your Keys, Your Coins"?

Transcript

Everyone's worried about quantum computers and whether you know all of blockchain will break. Uh there was just a tweet yesterday that caused a lot of noise about this and I want to address this. Um so back in the day when humans did math, I was one of those people who actually did math as an occupation. And I want to share with you my thoughts, my fears, and what I think could be the future of postquantum blockchain. Um, and it all boils down to the question of what will be the shelling point for money in the postquantum and post AI world. So, a

little bit of background. Back in the day, everyone agreed that money equals gold. And if you're sitting here, you probably know that there's a new and better form of gold uh that the world agrees to, and that is digital gold, also known as Bitcoin. More recently, a lot of people have been saying that for something to be money, it needs to have privacy and Zcash is starting to occupy this space. And the question is if at some point people will say wait a second money needs to have other attributes for it to be considered money. And that is what I want to talk about. So a little bit about myself. I helped build a lot of

the cryptography that is now used out there in blockchain. So I used to do research um until I found Bitcoin in 2013. Um, and then I realized that ZK, which was the stuff I was working on and that no one in the blockchain world heard about back then, is something that can solve both the privacy and the scalability problem of blockchain. So I shifted my work and with my co-authors we wrote a paper called Zerocash that then ended up being implemented in Zcash which I co-founded and I'm very very proud of the success of Zcash these days and you heard a lot of great talks about it. Um, but

that wasn't enough. And one of the things I was worried back then about was quantum threat and can you have better forms of cryptography which led to my work on ZK Starks which are hashbased and are safer from quantum and AI threats and that's how I came about to co-ound Starkware and Stark. So let's dive into the threat of a quantum computer. I want to explain to you what exactly it's about and what can we do to prevent a quantum based meltdown. So everyone loves blockchain because we know that you know your keys your coins but of course there's fine

print and the fine print is that it's your keys your coins provided the math underlying this remains hard and I want to give you some mental image for how encryption works when it comes to um controlling your keys. So, you know, you have some long sequence of uh numbers or letters that represents uh your key, your your secret key that controls your Bitcoin or Zcash or Starknet coins, doesn't matter, Ethereum. Okay? And as long as no one else knows that sequence, you're safe. Now, how do you how does someone else attack that and find your keys? So the classical way, classical

means, you know, on the laptops and smartphones that you have today. Um, finding out your sequence, your key, and stealing your coins is a little bit like finding an exit to a maze. So you're standing at a point in the maze and you have, you know, two paths diverging and you have to choose right or left. And whatever you choose, there's going to be another choice that you need to make, right? If you think about a key, like it's a long sequence. You have to guess what is the first letter, then the second letter, the third letter, and you got to get all of them right in order to exit the maze. So, breaking a key and stealing your coins is like finding your way out of a maze. And in a classical

computer, you need to do this by chance or exhaustively check all the different uh ways to turn. But here's where a quantum computer comes in and works differently. So you may be familiar with this concept of uh Shreddinger's cat which is at the same time alive and dead. So the quantum phenomena um means something like this that for certain periods of time in certain systems you can have the universe um in two different situations, right? Or if you think about the maze, what if you could clone yourself and go both right and left and do not only that but then

subsequently with every um you know intersection that you have you can clone again and again yourself. Okay. So this is what quantum mechanics allows you to do. So now think about this sort of uh you know person who has or a cat that has cloned itself and is trying out all different paths. There's a part in quantum mechanics called then measurement in which sort of the universe collapses and just picks one version right because we know that you know there's if there's one cat then we see only one cat. We don't have the ability to clone cats and people. So there's just this phenomena where for some time you can check many things in

parallel but then it all collapses down to one version of the universe. And the point is that certain mazes have a very nice structure that when you collapse the universe, it collapses to a state that corresponds to an exit of the maze. And that's how you break uh things like elliptic curve cryptography or factoring using a quantum computer. There's the ability to check all paths and then the universe sort of collapses to one state and one that one state happens to be the solution which happens to be your keys.

Okay. So that is the threat of a quantum computer and there is a class of uh cryptographic systems such as ZK Starks on which Starknet and other systems are based that doesn't have um inside it mazes that are nice and simple that allow the universe to find solutions and those classes of cryptographic systems are known as quantum resistant. So the quantum threat is that in Bitcoin, Ethereum, Zcash, basically all chains out there, your coins are secured right now by something that corresponds to a maze that a quantum computer can break because it's a very nice maze and we

want to move that. So I'm going back to this question of you know the the world will converge on some version of money at some point that also has to be safe uh from something like a quantum threat and the question is what will it converge on and obviously every existing coin wants to be it. Okay. So, we definitely need to have something that is postquantum safe. But there's another threat that is lurking behind because if you think about some of the replacements um out there suggested to replace the quantum susceptible stuff, the mazes that underly them or the math that underlies them is also in many cases very nice and structured. So there are things like uh lattice based

constructions and uh coding based constructions. But the problem is that the math underlying these things has seen some cracks in it. Meaning um especially AI has seen some of the schemes based on these other things um break and crack. So one example, there was a candidate for a postquantum secure signature called Hawk that was cracked in uh about 3 months ago by AI and the classic MC Ellis system based on coding theory that has been uh considered safe for 50 years saw another crack about a month ago. So the question is you know where is the safe ground that we should move to and the answer is you want to

move to things that are hashbased. So again, the tweet yesterday by Justin Drake uh talks about moving to hashbased cryptography. Everyone's talking about that and that's been my passion and our passion at Starker and Starknet since the beginning. So I want to show you a scene from a very nice movie uh from the '9s called Sneakers. You should all check it out. >> How is this possible? Cryptography systems are based on mathematical problems so complex they cannot be solved without a key.

>> Janick must have figured out a way to solve those problems without the key. And he hardwired it into that chip. >> Turn it off. >> Anybody want to crash a couple of passenger jets? >> I said turn it off. Turn it off. In this movie, there's it starts with a genius mathematician being murdered and the plot revolves around basically this genius being able to crack a lot of the math that underlies cryptography. It's a very nice movie. You should watch it. Um, but now we have this much bigger genius out there, which is AI. And we should be worried, will it crack open some of this cryptography that underlies uh all of the security of our systems? And when I

say all of our security, it goes way beyond just blockchain and Bitcoin because everything on the web, banking, messaging, identities, all of that is currently based on these public key encryption systems which are now well we should be at least a little bit more concerned about them. And uh there's a bigger issue looming and that is something that I am spending a lot of my time and my team is spending a lot of time thinking about. We're also being approached by sovereign wealth funds by wealth funds by you know very large institutions asking what is the path forward. Um so the path forward has to be that you want to be crypto and

cryptographically agile and move to the safest ground possible which is something that will be hashbased using technologies that are um proven and um use the right kind of zk. So I end with a question. I started money has been gold for millennia. Everyone sitting here probably agrees that Bitcoin is some new form better form of digital money. Some of you may agree that money needs to be private and are converging a little bit on Zcash. Um which is a project I really love. Um and the question is what can be postquantum

and agile money? Um so I hope it will be startnet but this will be something for the world to decide because just like gold you know there's no one person or entity that decided it. It's really a question about um you know what the world believes and we at Stark Net are going to make it agile, quantum resistant, AI ready uh using only hashbased cryptography. We have a migration road map. Currently we have a dependency on Ethereum because we settled onto it and the question is if Ethereum is too slow. Well, if Ethereum

is too slow to adopt, then Starknet will need to become an L1. And that is something that we are, you know, being asked and considering. And I'd love to talk to you guys about it if you're interested to hear more. So, with that, I want to end. If you want more resources, you can look uh we have a quantum hub. You can take and scan this uh QR code. Thank you very much.