Quantum money and the birth of quantum information
Charles Bennett's chance ocean encounter with cryptographer Gilles Brassard at a conference in Puerto Rico, where Bennett pitched the idea of using Heisenberg's uncertainty principle to create unforgeable quantum money, sparked a collaboration that founded the field of quantum information science. The two went on to develop quantum teleportation and won the Turing Prize together. The hosts use this origin story to frame the state of quantum computing in the early 1980s: Landauer's principle had shown heat dissipation was not an insurmountable barrier, Bell's theorem had established that quantum mechanics offers something genuinely beyond classical mechanics, and the stage was set for Feynman's entry.
- Brassard later said he listened politely because he was trapped in the middle of the ocean and had no way to escape the conversation.
- China has since demonstrated quantum teleportation at orbital distances, using a satellite to achieve a record transmission range that the hosts say is rooted in the same foundational work Bennett and Brassard began.
Transcript
This chapter, from the episode video's captions · 632 words
34:48Heisenberg's uncertainty principle to create unforgeable money. So this is before um Bitcoin was a thing, before the blockchain was a thing. They were trying to use quantum mechanics to create money that you couldn't fake, right? Um there's a funny story where Bennett attended the ITLE e conference on foundations of computer science in Puerto Rico and on one of these afternoons um this cryptographer Jillis Brassard he was swimming out in the beachfront hotel in San Juan and Bennett just swims up to him in the ocean and just starts ranting at him about this idea of quantum money. Okay. And and the quote we have from Brassard
35:30is like, "I was trapped, so I listened politely because they're in the middle of the ocean." He's just Brassard is just trying to have a good time before his talk about like cryptography. >> Puerto Rico. He's not trying to have a good time. >> Yeah. Yeah. He's trying to have a good time and and Bennett just swims up to him. He's like, "Yo, >> quantum money. >> I got this idea. >> I got this idea. It's going to make us rich." Probably. I don't know what he said, right? But um soon as he's listening to this thing, it's like doubt turns into fascination and he realizes like this could actually be some serious science. Um and the two of them form a collaboration that starts a whole new field of quantum information science. They win the touring prize together. Um
36:11and there's, you know, this discovery of a fundamental connection between physics and information. Quantum teleportation if you've ever heard of that's these guys. So they won the touring prize together. Um, but all from a serendipitous meeting in Puerto Rico in the ocean, right, where Bennett just like accosted this guy. This the only context I have recently of this idea of quantum teleportation was a news story maybe from a year or two ago where the the Chinese apparently were able to that they had the maximum distance of quantum teleportation of information. They had like a satellite in orbit. Oh, dude. I heard about that. >> And something on the ground. And when I
36:52heard that and cuz like the idea is like it is you cannot hack that information transfer in the way you would with normal signals intelligence. >> Yeah. That's like getting into quantum cryptography and stuff like that. Again, this is the stuff that these guys are doing, >> right? So, it starts here on a beach in Puerto Rico. >> Yeah. And now it's in orbit. Um, but that's we're we're going to get there, I think, in terms of being able to better understand >> what that means. But this is what we talk about when we say there all these stories and headlines and tech blogs and whatever. Oh quantum teleportation everything is going to be whatever. >> Yeah. But it it starts with these small meetings between human beings right at conferences crucially. Yes. So when
37:32people say that they don't want to fund conferences, conferences is where ideas come together. Osmosis >> you know like it's it's very important to bring human beings together. Um so this is the status in the early 1980s. Okay, we've got some indication that quantum computing could work, right? Like Landar's principle is not a no-go that we thought. There's ways to get around um heat dissipation. There's also this fundamental advantage that Bell gives you with quantum mechanics where he says that quantum mechanics is certainly very different from classical mechanics, right? And there is some magic there. Fineman is comes in over here. Okay, so this is where Fineman enters the fray. Um, he visits his old
From How Quantum Computing Actually Works (Part 1)
Part I of our quantum computing deep dive traces the field from Bell and Feynman to Deutsch and Shor—and explains what quantum computers actually do differently from classical machines.