WEBVTT 00:00:00.000 --> 00:00:03.040 Okay, let's unpack this. Imagine for a second 00:00:03.040 --> 00:00:05.839 that you are living in a house where the landlord 00:00:05.839 --> 00:00:09.800 has a master key. Not just, you know, for emergencies, 00:00:10.220 --> 00:00:12.580 but a key they can use whenever they feel like 00:00:12.580 --> 00:00:14.380 it. Okay, that's already a little unnerving. 00:00:14.380 --> 00:00:16.219 And not just to your front door, but to your 00:00:16.219 --> 00:00:19.559 diary, your safe, your filing cabinet. Wow. Even 00:00:19.559 --> 00:00:21.500 the letters you are writing before you've even 00:00:21.500 --> 00:00:24.170 put them in the envelope. Yeah, that's... That's 00:00:24.170 --> 00:00:26.210 a pretty terrifying thought. It feels incredibly 00:00:26.210 --> 00:00:29.149 invasive. It does. But for a very long time, 00:00:29.190 --> 00:00:32.429 that was effectively the reality of information 00:00:32.429 --> 00:00:34.969 security. Right. The government was the landlord. 00:00:35.189 --> 00:00:37.850 Exactly. If you wanted to keep a secret, you 00:00:37.850 --> 00:00:40.189 had to trust that the people in charge, specifically 00:00:40.189 --> 00:00:42.750 the government, wouldn't look at it. Or you had 00:00:42.750 --> 00:00:45.950 to like rely on a physical courier to carry your 00:00:45.950 --> 00:00:47.929 secrets across town. Right. It was a world of 00:00:47.929 --> 00:00:51.890 physical vulnerabilities and just total centralized 00:00:51.890 --> 00:00:54.299 control. There was no other way. Welcome back 00:00:54.299 --> 00:00:56.780 to the Deep Dive. Today we are tackling a subject 00:00:56.780 --> 00:00:59.560 that is quite literally the foundation of the 00:00:59.560 --> 00:01:02.240 modern digital world. It really is. We are talking 00:01:02.240 --> 00:01:04.540 about the man who changed that lock metaphor 00:01:04.540 --> 00:01:08.359 entirely. We are talking about Bailey Whitfield 00:01:08.359 --> 00:01:11.340 Diffie, known to the world as Wit. Wit Diffie, 00:01:11.359 --> 00:01:15.060 a mathematician, a cryptographer, and frankly, 00:01:15.260 --> 00:01:16.760 one of the most interesting characters we have 00:01:16.760 --> 00:01:19.540 ever profiled. He's a real iconoclast. Absolutely. 00:01:19.780 --> 00:01:22.659 And our mission for this deep dive is to explore 00:01:22.659 --> 00:01:25.379 how this one guy who, by the way, started out 00:01:25.379 --> 00:01:28.299 as a pacifist trying to dodge the draft, ended 00:01:28.299 --> 00:01:30.599 up breaking the government's absolute monopoly 00:01:30.599 --> 00:01:33.280 on cryptography. It's a classic David and Goliath 00:01:33.280 --> 00:01:36.239 story, but, you know, with a lot more math. And 00:01:36.239 --> 00:01:38.280 maybe a bit more hair. A lot more hair. We're 00:01:38.280 --> 00:01:40.099 going to look at the New Directions in Cryptography 00:01:40.099 --> 00:01:44.140 paper he wrote with Martin Hellman in 1976. And 00:01:44.140 --> 00:01:45.939 this wasn't just, you know, some research paper. 00:01:46.060 --> 00:01:48.319 No, no. It was a revolution. It really was. It's 00:01:48.319 --> 00:01:50.760 hard to overstate. That paper is the reason you 00:01:50.760 --> 00:01:52.640 can buy something on Amazon without your credit 00:01:52.640 --> 00:01:54.519 card number being stolen instantly. It's the 00:01:54.519 --> 00:01:57.319 reason digital currencies can even exist as a 00:01:57.319 --> 00:02:01.319 concept. It is, and this is not an exaggeration, 00:02:01.400 --> 00:02:04.140 the bedrock of the Internet as we know it. We 00:02:04.140 --> 00:02:06.299 are going to break down the mechanics of the 00:02:06.299 --> 00:02:08.800 split -key breakthrough, which solved a problem 00:02:08.800 --> 00:02:11.659 that had plagued code makers for, what, centuries? 00:02:11.900 --> 00:02:14.259 For centuries, yeah. And we'll look at Diffie, 00:02:14.379 --> 00:02:18.580 the man, the iconoclast, who paradoxically started 00:02:18.580 --> 00:02:21.000 his career at a defense contractor. And that 00:02:21.000 --> 00:02:23.280 contradiction is where it gets really, really 00:02:23.280 --> 00:02:25.860 interesting. Oh, for sure. He's a man of principles, 00:02:26.039 --> 00:02:28.740 but he had to navigate a very messy world to 00:02:28.740 --> 00:02:30.889 get his ideas out there. So let's jump right 00:02:30.889 --> 00:02:33.590 in. Who is Whitfield Diffie? He was born in Washington, 00:02:33.750 --> 00:02:37.389 D .C. in 1944. Right. And right off the bat, 00:02:37.430 --> 00:02:39.310 looking at his background, you can see the ingredients 00:02:39.310 --> 00:02:42.750 for like an intellectual powerhouse. Oh, definitely. 00:02:43.030 --> 00:02:45.530 Yeah. It was a household that valued the life 00:02:45.530 --> 00:02:48.050 of the mind above almost everything else. I mean, 00:02:48.050 --> 00:02:50.310 his mother, Justine Louise Whitfield, she was 00:02:50.310 --> 00:02:52.550 a writer and a scholar. Okay. And his father, 00:02:52.729 --> 00:02:55.669 Bailey Walleys Diffie, was a professor of Iberian 00:02:55.669 --> 00:02:57.969 history and culture at the City College of New 00:02:57.969 --> 00:03:00.919 York. So he's growing up surrounded by books, 00:03:01.060 --> 00:03:03.639 by history, by big ideas. It's not your average 00:03:03.639 --> 00:03:06.039 upbringing. Exactly. It wasn't a home where you 00:03:06.039 --> 00:03:07.840 just came home from school and watched TV. It 00:03:07.840 --> 00:03:10.719 was a home where you debated ideas. But there 00:03:10.719 --> 00:03:15.699 is this one specific moment, this catalyst that 00:03:15.699 --> 00:03:18.419 really set him on his path. He was 10 years old. 00:03:18.539 --> 00:03:20.680 Do you have the note on this? I do. And it is 00:03:20.680 --> 00:03:24.240 such a specific, almost cinematic detail. His 00:03:24.240 --> 00:03:26.939 father, the professor, brought home the entire 00:03:26.939 --> 00:03:29.699 cryptography shelf. From the City College Library. 00:03:30.159 --> 00:03:33.020 Just think about that image for a second. Most 00:03:33.020 --> 00:03:35.560 ads bring home a baseball glove or, you know, 00:03:35.580 --> 00:03:37.879 a model train set. Right. Bailey Diffie goes 00:03:37.879 --> 00:03:39.960 to the university library, looks at the shelf 00:03:39.960 --> 00:03:42.419 labeled cryptography, and basically sweeps the 00:03:42.419 --> 00:03:44.919 whole thing into a bag. Uh, laughing. Here you 00:03:44.919 --> 00:03:48.340 go, son. Crack these. Essentially, yes. And for 00:03:48.340 --> 00:03:50.280 a 10 -year -old Whitfield Diffie, that was it. 00:03:50.360 --> 00:03:52.680 That was the spark. He didn't just look at the 00:03:52.680 --> 00:03:55.199 pictures. He devoured the texts. He was bitten 00:03:55.199 --> 00:03:57.080 by the cryptography bug right then and there. 00:03:57.419 --> 00:03:59.560 But what's fascinating here is that despite this 00:03:59.560 --> 00:04:02.060 obvious brilliance, I mean, he's reading college 00:04:02.060 --> 00:04:04.479 -level texts on ciphers at age 10. Yeah, which 00:04:04.479 --> 00:04:06.599 is insane. He wasn't exactly a model student 00:04:06.599 --> 00:04:09.259 in the traditional sense. No, and this is a pattern 00:04:09.259 --> 00:04:11.300 we see with a lot of these outlier geniuses. 00:04:11.379 --> 00:04:14.639 The standard academic conveyor belt just, it 00:04:14.639 --> 00:04:16.600 just doesn't work for them. So let's unpack his 00:04:16.600 --> 00:04:19.740 time at Jamaica High School in Queens. The source 00:04:19.740 --> 00:04:22.519 material says he performed competently, but... 00:04:22.519 --> 00:04:24.620 But never did apply himself to the degree his 00:04:24.620 --> 00:04:27.449 father hoped. performed competently is such a 00:04:27.449 --> 00:04:29.170 polite way of saying he was bored out of his 00:04:29.170 --> 00:04:32.170 mind totally he did enough to get by but he wasn't 00:04:32.170 --> 00:04:34.670 chasing the gold stars he wasn't interested in 00:04:34.670 --> 00:04:36.290 jumping through the hoops just because the teacher 00:04:36.290 --> 00:04:38.509 said so and speaking of hoops this is where we 00:04:38.509 --> 00:04:41.310 get the first real glimpse of his rebellious 00:04:41.310 --> 00:04:43.699 streak He didn't even get a standard academic 00:04:43.699 --> 00:04:46.860 diploma from high school. No, he didn't. He graduated 00:04:46.860 --> 00:04:49.519 with a local diploma because he refused, flat 00:04:49.519 --> 00:04:53.060 out refused, to take the statewide regents' examinations. 00:04:53.100 --> 00:04:55.040 For those of us who didn't grow up in New York, 00:04:55.139 --> 00:04:58.579 the regents are a huge deal. They are the gateway 00:04:58.579 --> 00:05:02.480 to a real diploma. Refusing to take them is almost 00:05:02.480 --> 00:05:05.750 unheard of for a smart kid. It really is. But 00:05:05.750 --> 00:05:07.410 you have to understand his logic. What was the 00:05:07.410 --> 00:05:09.589 thinking there? It was a power move. I mean, 00:05:09.610 --> 00:05:11.810 he had already secured admission to MIT. The 00:05:11.810 --> 00:05:14.310 Massachusetts Institute of Technology. The top 00:05:14.310 --> 00:05:16.850 engineering school in the country, maybe the 00:05:16.850 --> 00:05:22.050 world. And he got in based purely on his stratospheric 00:05:22.050 --> 00:05:25.329 scores on standardized tests. He had the SAT 00:05:25.329 --> 00:05:28.009 scores. He had the aptitude. MIT said, you're 00:05:28.009 --> 00:05:30.050 in. So he basically looked at his high school 00:05:30.050 --> 00:05:32.860 administration and said. I'm going to the best 00:05:32.860 --> 00:05:35.079 engineering school on the planet. I don't need 00:05:35.079 --> 00:05:38.699 your test. Exactly. It speaks to that iconoclast 00:05:38.699 --> 00:05:41.740 label he uses for himself. He plays by his own 00:05:41.740 --> 00:05:44.100 rules. If a rule doesn't make logical sense to 00:05:44.100 --> 00:05:47.060 him, or if you use it as just bureaucratic waste 00:05:47.060 --> 00:05:49.600 of time, he just ignores it. So he gets to MIT, 00:05:50.040 --> 00:05:52.459 the promised land for geniuses, right? You would 00:05:52.459 --> 00:05:54.240 think he would land there and finally feel like 00:05:54.240 --> 00:05:56.500 he was home. You would think so. But it sounds 00:05:56.500 --> 00:05:58.379 like it wasn't exactly smooth sailing there either. 00:05:58.720 --> 00:06:01.620 No, the sources say he felt unengaged. He actually 00:06:01.620 --> 00:06:03.579 considered transferring to Berkeley because he 00:06:03.579 --> 00:06:05.319 thought it would be a more hospitable academic 00:06:05.319 --> 00:06:08.000 environment. Which is interesting. MIT is known 00:06:08.000 --> 00:06:11.120 for being a grinder. It's intense, it's competitive, 00:06:11.399 --> 00:06:14.279 and it's very, very structured. And Diffie, as 00:06:14.279 --> 00:06:16.959 we've seen, resists structure. He absolutely 00:06:16.959 --> 00:06:19.279 does. He was probably looking for something a 00:06:19.279 --> 00:06:21.819 bit more free thinking, more philosophical, which 00:06:21.819 --> 00:06:23.879 Berkeley certainly represents. But he stayed 00:06:23.879 --> 00:06:26.980 at MIT. And this brings us to one of my favorite 00:06:26.980 --> 00:06:30.259 details in his entire biography. It's about his 00:06:30.259 --> 00:06:32.620 relationship with computers. This is great. I 00:06:32.620 --> 00:06:35.319 love this part. So he starts programming computers 00:06:35.319 --> 00:06:39.319 at MIT, but not because he loved them. Not at 00:06:39.319 --> 00:06:42.639 all. No, he did it to cultivate a practical skill 00:06:42.639 --> 00:06:45.399 set. He needed a way to make himself useful, 00:06:45.579 --> 00:06:48.319 employable. But he actually viewed computers 00:06:48.319 --> 00:06:52.420 as very low class. Low class. The man who wins 00:06:52.420 --> 00:06:54.579 the Turing Award, the Nobel Prize of Computing 00:06:54.579 --> 00:06:56.959 Thought Computers, were low class. It's incredible. 00:06:57.160 --> 00:06:59.639 It sounds absurd to us now, but you have to put 00:06:59.639 --> 00:07:01.620 yourself in the mindset of a pure mathematician 00:07:01.620 --> 00:07:05.240 in the early 1960s. To him, pure math. Things 00:07:05.240 --> 00:07:07.639 like partial differential equations, topology, 00:07:07.839 --> 00:07:10.060 abstract theory, that was art. That was the high 00:07:10.060 --> 00:07:11.740 culture. That was high culture. It was poetry. 00:07:12.250 --> 00:07:14.110 Yeah. And computers. Computers were machinery. 00:07:14.509 --> 00:07:16.709 They were just machinery. It was banging on a 00:07:16.709 --> 00:07:19.790 keyboard. They were loud, clunky, utilitarian. 00:07:20.170 --> 00:07:22.189 To him, working on a computer was like being 00:07:22.189 --> 00:07:24.949 a mechanic. It was manual labor compared to the 00:07:24.949 --> 00:07:27.449 elegance of pure mathematics. It's amazing how 00:07:27.449 --> 00:07:29.889 life works out. He stuck it out, though, and 00:07:29.889 --> 00:07:32.629 he graduated with a B .S. in mathematics in 1965. 00:07:33.089 --> 00:07:37.100 He did. But then we hit the mid 60s and the world 00:07:37.100 --> 00:07:39.399 outside of MIT is getting very, very complicated. 00:07:39.660 --> 00:07:41.959 The Vietnam War is ramping up. Right. And this 00:07:41.959 --> 00:07:44.100 is crucial context for understanding Diffie's 00:07:44.100 --> 00:07:46.579 motivations. This isn't just a math story. It's 00:07:46.579 --> 00:07:48.980 a political story, too. So Diffie finds himself 00:07:48.980 --> 00:07:52.259 in a serious moral conflict. He does. It's 1965. 00:07:52.680 --> 00:07:56.120 The draft is in full swing. If you were a young, 00:07:56.240 --> 00:07:58.699 healthy male. you were probably going to Vietnam 00:07:58.699 --> 00:08:00.519 unless you have a very good reason not to. And 00:08:00.519 --> 00:08:02.819 Diffie was a pacifist. A committed pacifist. 00:08:02.860 --> 00:08:05.540 He opposed the war fundamentally on moral grounds. 00:08:05.660 --> 00:08:08.500 So he needs to avoid the draft, but he also needs 00:08:08.500 --> 00:08:12.480 a job. So he finds a loophole. And it is a deeply, 00:08:12.579 --> 00:08:14.759 deeply ironic loophole. He takes a job at the 00:08:14.759 --> 00:08:17.459 MITRE Corporation. The MITRE Corporation, which 00:08:17.459 --> 00:08:20.459 is a defense contractor. So he goes to work for 00:08:20.459 --> 00:08:22.420 the military -industrial complex specifically 00:08:22.420 --> 00:08:25.560 to avoid being drafted into the military. I mean, 00:08:25.560 --> 00:08:28.329 the irony is just... It's perfect. That is a 00:08:28.329 --> 00:08:31.009 delicate tightrope to walk. I won't fight in 00:08:31.009 --> 00:08:32.990 your war, but I will work for the company that 00:08:32.990 --> 00:08:36.029 builds the systems for it. It is. But he managed 00:08:36.029 --> 00:08:39.090 to carve out a niche for himself. He worked there 00:08:39.090 --> 00:08:43.289 from 1965 to 1969, but he was very careful about 00:08:43.289 --> 00:08:45.509 what projects he worked on. So he wasn't working 00:08:45.509 --> 00:08:48.970 on weapons systems? No. He focused on non -military 00:08:48.970 --> 00:08:50.789 applications. He worked on something called Math 00:08:50.789 --> 00:08:53.470 Lab. Math Lab. What was that? It was an early 00:08:53.470 --> 00:08:56.139 symbolic manipulation system. Basically it was 00:08:56.139 --> 00:08:58.220 software that could do algebra and calculus. 00:08:58.909 --> 00:09:00.950 It was a tool for mathematicians and scientists. 00:09:01.210 --> 00:09:03.929 So technically he was keeping his hands clean. 00:09:04.110 --> 00:09:06.250 In his mind, yes. He wasn't building missile 00:09:06.250 --> 00:09:08.269 guidance systems. He was building a very sophisticated 00:09:08.269 --> 00:09:10.649 calculator. But eventually that pull of the West 00:09:10.649 --> 00:09:13.370 Coast and maybe that desire for a more hospitable 00:09:13.370 --> 00:09:15.809 environment he felt back in college, it took 00:09:15.809 --> 00:09:17.529 over. Yeah, it seems like it was always in the 00:09:17.529 --> 00:09:19.990 back of his mind. So in 1969, he moves to the 00:09:19.990 --> 00:09:22.450 Stanford Artificial Intelligence Laboratory or 00:09:22.450 --> 00:09:25.450 SAIL. And this is a legendary place in the history 00:09:25.450 --> 00:09:27.919 of computing. This is where the future was being 00:09:27.919 --> 00:09:30.399 invented. He's working under John McCarthy. The 00:09:30.399 --> 00:09:32.740 John McCartan. The literal father of artificial 00:09:32.740 --> 00:09:36.240 intelligence. He coined the term AI. Wow. So 00:09:36.240 --> 00:09:38.820 what was Diffie doing there? He was working as 00:09:38.820 --> 00:09:43.740 a research programmer on LISP 1 .6. LISP is a 00:09:43.740 --> 00:09:46.480 programming language that was huge in AI at the 00:09:46.480 --> 00:09:49.259 time. He was helping with correctness problems, 00:09:49.440 --> 00:09:51.759 basically making sure the code did exactly what 00:09:51.759 --> 00:09:53.559 it was supposed to do mathematically, proving 00:09:53.559 --> 00:09:56.029 that the logic was sound. So he's deep in the 00:09:56.029 --> 00:09:59.669 AI world. But while he's there, something happens. 00:10:00.009 --> 00:10:02.970 That childhood spark, the one from the library 00:10:02.970 --> 00:10:06.350 shelf full of crypto books, it starts to reignite. 00:10:06.429 --> 00:10:09.250 Yes. His interest in cryptography starts to move 00:10:09.250 --> 00:10:13.210 from just a childhood hobby to a professional 00:10:13.210 --> 00:10:15.649 obsession. Why then? He starts realizing that 00:10:15.649 --> 00:10:17.629 as computers become more connected, as we build 00:10:17.629 --> 00:10:20.519 these networks. The need for security is going 00:10:20.519 --> 00:10:22.679 to be paramount. He saw the future. But there 00:10:22.679 --> 00:10:24.879 was a problem, right? In the late 60s and early 00:10:24.879 --> 00:10:27.000 70s, you couldn't just go to the library and 00:10:27.000 --> 00:10:29.059 check out the latest research on crypto. No. 00:10:29.379 --> 00:10:32.360 That shelf his dad brought home, that was old 00:10:32.360 --> 00:10:35.120 stuff. Classical ciphers, things that had been 00:10:35.120 --> 00:10:38.080 around for decades or centuries. The new stuff, 00:10:38.240 --> 00:10:41.240 the modern computer -based research, was almost 00:10:41.240 --> 00:10:44.279 exclusively the domain of the government. Specifically, 00:10:44.279 --> 00:10:47.700 the National Security Agency. The NSA. Right. 00:10:47.799 --> 00:10:50.940 They held a complete and total monopoly on the 00:10:50.940 --> 00:10:53.879 knowledge. If you weren't in the NSA or working 00:10:53.879 --> 00:10:56.019 for a direct contractor with high -level clearance, 00:10:56.120 --> 00:10:58.179 you were shut out. The research was classified. 00:10:58.379 --> 00:11:00.600 It might as well not exist for a civilian. So 00:11:00.600 --> 00:11:02.539 if you are an independent researcher like Diffie 00:11:02.539 --> 00:11:04.840 who is starting to get obsessed with this topic, 00:11:05.039 --> 00:11:07.559 what do you do? Well, if you are Whitfield Diffie, 00:11:07.620 --> 00:11:10.399 you do something radical. In May of 1973, he 00:11:10.399 --> 00:11:13.490 leaves SAIL. He quits his job. Just quits. Just 00:11:13.490 --> 00:11:16.669 quits to pursue independent research in cryptography. 00:11:16.850 --> 00:11:20.090 With no grant, no institutional backing. No backing. 00:11:20.370 --> 00:11:24.450 Just a burning curiosity and, I guess, a lot 00:11:24.450 --> 00:11:26.230 of self -confidence. And this kicks off what 00:11:26.230 --> 00:11:28.389 I like to call the quest. Tell me about the quest. 00:11:28.470 --> 00:11:30.330 This sounds like something out of a movie. It 00:11:30.330 --> 00:11:33.330 kind of is. He realized he couldn't find the 00:11:33.330 --> 00:11:35.029 answers in the standard journals because the 00:11:35.029 --> 00:11:37.230 answers weren't in the journals. They were locked 00:11:37.230 --> 00:11:40.740 in safes at Fort Meade. So... To quote the source, 00:11:40.899 --> 00:11:43.519 he went around doing one of the things I'm good 00:11:43.519 --> 00:11:46.519 at, which is digging up rare manuscripts in libraries, 00:11:46.879 --> 00:11:49.360 driving around, visiting friends at universities. 00:11:49.700 --> 00:11:51.840 I love this image. It's like a cryptographic 00:11:51.840 --> 00:11:54.600 road trip movie. He's driving across America 00:11:54.600 --> 00:11:58.019 in, I don't know, a beat up station wagon. Oh, 00:11:58.019 --> 00:12:00.740 right. Digging through dusty archives, trying 00:12:00.740 --> 00:12:03.100 to piece together this forbidden knowledge from 00:12:03.100 --> 00:12:05.539 scraps and footnotes. And he wasn't alone on 00:12:05.539 --> 00:12:07.659 this journey. He was assisted by his girlfriend. 00:12:08.220 --> 00:12:10.200 Mary Fisher, who would later become his wife. 00:12:10.799 --> 00:12:13.600 They were this team out there together hunting 00:12:13.600 --> 00:12:16.179 for clues in a field that the government actively 00:12:16.179 --> 00:12:18.679 tried to keep invisible. It really is a detective 00:12:18.679 --> 00:12:21.000 story. He's looking for a science that officially 00:12:21.000 --> 00:12:24.019 doesn't exist for the public. Exactly. And that 00:12:24.019 --> 00:12:26.639 road trip leads them to a very, very important 00:12:26.639 --> 00:12:30.220 meeting in the summer of 1974. Where did they 00:12:30.220 --> 00:12:32.740 go? They visit the Thomas J. Watson Research 00:12:32.740 --> 00:12:35.259 Center in New York. That's IBM's main research 00:12:35.259 --> 00:12:38.299 headquarters. Why IBM? What was so special about 00:12:38.299 --> 00:12:42.799 them? Because IBM was unique. At the time, they 00:12:42.799 --> 00:12:45.740 housed one of the only non -governmental cryptographic 00:12:45.740 --> 00:12:48.559 research groups in the entire country. Okay. 00:12:48.799 --> 00:12:50.740 They were doing work for banks and businesses 00:12:50.740 --> 00:12:53.940 who needed to secure their own data. So if anyone 00:12:53.940 --> 00:12:57.120 outside the NSA knew anything, it was the guys 00:12:57.120 --> 00:12:59.600 at IBM. So Diffie walks in. He must be thinking, 00:12:59.659 --> 00:13:01.879 this is it. He meets with a guy named Alan Kahnheim, 00:13:01.980 --> 00:13:04.220 who is the group director. Right. And Diffie's 00:13:04.220 --> 00:13:06.950 probably thinking, finally. Someone I can talk 00:13:06.950 --> 00:13:09.730 to. Someone who speaks my language. But he hits 00:13:09.730 --> 00:13:12.929 a wall, doesn't he? A brick wall. A classified 00:13:12.929 --> 00:13:16.210 brick wall. Kahnheim knows a lot. He almost certainly 00:13:16.210 --> 00:13:18.090 knows the answers to the questions Diffie is 00:13:18.090 --> 00:13:21.029 asking. But Kahnheim is under a secrecy order. 00:13:21.289 --> 00:13:23.730 Meaning he legally cannot talk about it. Correct. 00:13:23.789 --> 00:13:26.629 He literally cannot tell Diffie anything without 00:13:26.629 --> 00:13:28.909 risking prison time or losing his security clearance. 00:13:29.320 --> 00:13:31.000 It's a total dead end. That must have been incredibly 00:13:31.000 --> 00:13:33.120 frustrating. You find the expert, you're in the 00:13:33.120 --> 00:13:34.620 room, you ask the question, and the guy just 00:13:34.620 --> 00:13:37.200 stares at you and says, I can't say. It was frustrating, 00:13:37.379 --> 00:13:40.100 for sure. But Kahnheim did give him something. 00:13:40.240 --> 00:13:42.779 It wasn't an answer to a math problem, but it 00:13:42.779 --> 00:13:45.179 was perhaps more valuable. He gave him a referral. 00:13:45.519 --> 00:13:49.559 A name. A name. He told Diffie, I can't talk 00:13:49.559 --> 00:13:51.879 to you, but you should go meet Martin Hellman. 00:13:51.980 --> 00:13:54.120 And who was Martin Hellman at this point? He 00:13:54.120 --> 00:13:56.139 is a young electrical engineering professor at 00:13:56.139 --> 00:13:59.399 Stanford. And, just like Diffie, He was an outsider. 00:13:59.820 --> 00:14:02.360 He was pursuing a cryptographic research program 00:14:02.360 --> 00:14:05.200 on his own, facing the same walls of silence 00:14:05.200 --> 00:14:07.980 that Diffie was facing. He was another lone wolf. 00:14:08.220 --> 00:14:10.940 So Kahnheim basically says, I can't talk to you, 00:14:10.960 --> 00:14:13.220 but go talk to this other guy in California who 00:14:13.220 --> 00:14:15.279 is crazy enough to be asking the same questions 00:14:15.279 --> 00:14:17.759 you are. That's exactly it. And that suggestion, 00:14:18.059 --> 00:14:20.759 that one little piece of advice, changed history. 00:14:21.399 --> 00:14:24.039 If Conheim hadn't given that name, public key 00:14:24.039 --> 00:14:25.779 cryptography might have been delayed by years, 00:14:26.000 --> 00:14:28.340 maybe decades. So Diffie gets back in the car 00:14:28.340 --> 00:14:30.659 or maybe a plane at this point and goes back 00:14:30.659 --> 00:14:32.899 to Stanford. He sets up a meeting with Hellman. 00:14:33.019 --> 00:14:34.539 And it was supposed to be a half hour meet and 00:14:34.539 --> 00:14:37.320 greet. You know, hi, I'm Wit. I like codes. Hi, 00:14:37.480 --> 00:14:39.820 I'm Martin. Me too. But it didn't stay a half 00:14:39.820 --> 00:14:43.799 hour. No, it lasted for hours. It stretched into 00:14:43.799 --> 00:14:46.980 the evening. It was a mind meld. They realized 00:14:46.980 --> 00:14:49.200 immediately that they were on the exact same 00:14:49.200 --> 00:14:51.289 wavelength. They were both wrestling with the 00:14:51.289 --> 00:14:53.289 exact same problem. What problem was that? The 00:14:53.289 --> 00:14:55.690 key distribution problem. How do you get a secret 00:14:55.690 --> 00:14:58.950 key from one person to another without an eavesdropper 00:14:58.950 --> 00:15:01.870 grabbing it? They shared ideas. They shared frustrations. 00:15:01.929 --> 00:15:04.009 It was the beginning of one of the most important 00:15:04.009 --> 00:15:06.389 partnerships in the history of computer science. 00:15:06.610 --> 00:15:10.570 It's like Lennon meeting McCartney or Jobs meeting 00:15:10.570 --> 00:15:13.169 Wozniak. It really is. They had complementary 00:15:13.169 --> 00:15:15.929 skills. Hellman was the academic, the engineer, 00:15:16.070 --> 00:15:17.769 the guy who understood the structure and the 00:15:17.769 --> 00:15:20.289 formalisms. And Diffie. Diffie was the visionary, 00:15:20.470 --> 00:15:22.850 the pure mathematician, the guy you could see 00:15:22.850 --> 00:15:24.870 around corners and imagine things that didn't 00:15:24.870 --> 00:15:27.149 exist yet. And Hellman actually hires Diffie, 00:15:27.169 --> 00:15:29.950 right? He brings him into the fold. Yes. Hellman 00:15:29.950 --> 00:15:32.809 had a small grant, and he used it to hire Diffie 00:15:32.809 --> 00:15:35.090 as a part -time research programmer for the spring 00:15:35.090 --> 00:15:38.490 1975 term. And here is where the story loops 00:15:38.490 --> 00:15:41.230 back on itself in a funny way. Under Hellman's 00:15:41.230 --> 00:15:43.570 sponsorship, Diffie decides to give the academic 00:15:43.570 --> 00:15:47.370 path one more try. Yes. He enrolls as a doctoral 00:15:47.370 --> 00:15:51.129 student at Stanford in June 1975. So he's going 00:15:51.129 --> 00:15:53.809 for his PhD. He's going to become Dr. Diffie. 00:15:53.909 --> 00:15:57.110 Well, history has a way of repeating itself, 00:15:57.230 --> 00:15:59.850 doesn't it? Let me guess. The structure problem 00:15:59.850 --> 00:16:02.470 again. He couldn't handle the homework. The structure 00:16:02.470 --> 00:16:06.610 problem, big time. Diffie was, quote, unable 00:16:06.610 --> 00:16:09.029 to acclimate to homework assignments and the 00:16:09.029 --> 00:16:11.679 structure. He just couldn't do the busy work. 00:16:11.820 --> 00:16:15.000 He wanted to solve the big problem, not do problem 00:16:15.000 --> 00:16:17.600 sets. But the specific reason he dropped out, 00:16:17.639 --> 00:16:19.779 I have it here in the notes, and it is just hilarious. 00:16:19.879 --> 00:16:22.600 It's so perfectly him. It's classic Diffie. He 00:16:22.600 --> 00:16:24.940 failed to complete a required physical examination. 00:16:25.480 --> 00:16:27.759 A physical exam, like go to the doctor, get your 00:16:27.759 --> 00:16:29.460 blood pressure checked, turn your head and cough, 00:16:29.659 --> 00:16:31.980 a routine checkup. Then he just didn't do it. 00:16:32.000 --> 00:16:34.980 Why? His reason was... I didn't feel like doing 00:16:34.980 --> 00:16:36.919 it. I didn't get around to it. That is amazing. 00:16:36.980 --> 00:16:39.460 He is working on math that will secure the entire 00:16:39.460 --> 00:16:41.720 future of the Internet, but he can't be bothered 00:16:41.720 --> 00:16:43.460 to go get a checkup, so he drops out of the Ph 00:16:43.460 --> 00:16:46.320 .D. program. It shows you exactly where his priorities 00:16:46.320 --> 00:16:48.700 were. If it wasn't intellectually interesting 00:16:48.700 --> 00:16:51.820 to him, it didn't exist. But, and this is crucial, 00:16:52.100 --> 00:16:54.240 even though he dropped out of the doctoral program, 00:16:54.580 --> 00:16:57.299 he remained employed in Hellman's lab as a research 00:16:57.299 --> 00:17:00.159 assistant through 1978. Which is good, because 00:17:00.159 --> 00:17:02.279 they had work to do. They were on the verge of 00:17:02.279 --> 00:17:05.220 the big one. So let's get into the meat of it. 00:17:05.259 --> 00:17:08.759 Section four, the breakthrough. This is the turning 00:17:08.759 --> 00:17:11.599 point. This is where the world changes. OK, so 00:17:11.599 --> 00:17:14.059 to understand why their work was so revolutionary, 00:17:14.180 --> 00:17:17.660 we need to really, really understand the problem 00:17:17.660 --> 00:17:20.180 they were trying to solve. We've mentioned the 00:17:20.180 --> 00:17:22.519 government monopoly, but technically speaking, 00:17:22.819 --> 00:17:24.640 what was the issue with encryption at the time? 00:17:24.819 --> 00:17:26.680 The fundamental problem was something called 00:17:26.680 --> 00:17:29.960 key distribution. Key distribution. Break that 00:17:29.960 --> 00:17:32.400 down for us. Let's use an analogy. OK. Imagine 00:17:32.400 --> 00:17:34.920 we want to send a secret message to each other. 00:17:35.039 --> 00:17:37.579 In traditional cryptography, what we now call 00:17:37.579 --> 00:17:40.640 symmetric cryptography, we both need the same 00:17:40.640 --> 00:17:43.440 key to lock and unlock the message. Right, like 00:17:43.440 --> 00:17:46.059 a house key. If I lock the door with a physical 00:17:46.059 --> 00:17:48.779 key, you need an identical copy of that same 00:17:48.779 --> 00:17:51.619 key to open it. Exactly. But here's the problem. 00:17:51.819 --> 00:17:53.619 How do I get you that key in the first place? 00:17:53.859 --> 00:17:56.400 Well, I hand it to you. Or I make a copy and 00:17:56.400 --> 00:17:59.079 give it to you. If we're in the same room, sure. 00:17:59.470 --> 00:18:01.569 That's easy. But what if you were in New York 00:18:01.569 --> 00:18:03.349 and I'm in London? I have to send it to you. 00:18:03.490 --> 00:18:07.329 Okay, so I mail it to you in a secure envelope. 00:18:07.650 --> 00:18:09.690 But if you mail it, someone at the post office 00:18:09.690 --> 00:18:11.750 might open the envelope, make a copy of the key, 00:18:11.869 --> 00:18:15.029 and seal it back up. You'd never know. And now 00:18:15.029 --> 00:18:17.329 they have a copy of our key forever. Okay, bad 00:18:17.329 --> 00:18:19.890 idea. I could read the key to you over the phone. 00:18:20.009 --> 00:18:22.809 But the phone lines might be tapped. An eavesdropper 00:18:22.809 --> 00:18:24.710 could just write it down. I see the problem. 00:18:25.170 --> 00:18:27.730 To send a secret message securely, we need a 00:18:27.730 --> 00:18:30.640 secret key. But to share the secret key securely, 00:18:30.819 --> 00:18:33.480 we need a secure channel to begin with. It's 00:18:33.480 --> 00:18:36.099 a catch -22. Precisely. It's a bootstrapping 00:18:36.099 --> 00:18:38.579 problem. Before Diffie and Hellman, the only 00:18:38.579 --> 00:18:41.440 way to solve this was to have a trusted third 00:18:41.440 --> 00:18:44.380 party. Like who? Give me an example. Usually 00:18:44.380 --> 00:18:47.160 a military courier with a locked briefcase handcuffed 00:18:47.160 --> 00:18:50.259 to his wrist flying on a secure plane. Or, in 00:18:50.259 --> 00:18:52.420 the government's case, the NSA itself managed 00:18:52.420 --> 00:18:54.380 all the keys. They were the central authority. 00:18:54.539 --> 00:18:56.680 You had to trust them. And Diffie did not like 00:18:56.680 --> 00:18:59.910 that. At all. No. Divvy was an individualist, 00:18:59.930 --> 00:19:02.569 a libertarian, really. He wanted to eliminate 00:19:02.569 --> 00:19:05.130 the need for a trusted third party. He wanted 00:19:05.130 --> 00:19:08.069 two things. One, privacy from eavesdroppers. 00:19:08.170 --> 00:19:11.549 And two, a way to make secure electronic transactions 00:19:11.549 --> 00:19:14.569 without needing a central authority like a bank 00:19:14.569 --> 00:19:16.710 or the government to oversee every single step. 00:19:16.970 --> 00:19:20.690 So in 1976, they published this paper, New Directions 00:19:20.690 --> 00:19:23.710 in Cryptography. And they propose a solution 00:19:23.710 --> 00:19:26.630 that is just. It's completely out of left field. 00:19:26.730 --> 00:19:30.150 The split key. Or what we now call public key 00:19:30.150 --> 00:19:32.829 cryptography. How does the split key work? It 00:19:32.829 --> 00:19:35.690 was a stunning conceptual breakthrough. They 00:19:35.690 --> 00:19:37.769 had this realization that the key to lock the 00:19:37.769 --> 00:19:40.410 message and the key to unlock the message didn't 00:19:40.410 --> 00:19:42.109 have to be the same key. Okay, that's already 00:19:42.109 --> 00:19:44.029 bending my brain a little. Stay with me. They 00:19:44.029 --> 00:19:46.049 split the key into two mathematically linked 00:19:46.049 --> 00:19:48.970 parts. Every user has a public key and a private 00:19:48.970 --> 00:19:51.690 key. So I have two keys, not one. Right. You 00:19:51.690 --> 00:19:53.369 have a key pair. The public key is just that. 00:19:53.450 --> 00:19:55.509 It's public. You can put it in a directory. You 00:19:55.509 --> 00:19:57.490 can put it on your website. You can tattoo it 00:19:57.490 --> 00:19:59.109 on your forehead. Doesn't matter who sees it. 00:19:59.250 --> 00:20:02.349 And the private key? The private key, you keep 00:20:02.349 --> 00:20:05.150 secret. No one else ever sees it. You guard it 00:20:05.150 --> 00:20:07.069 with your life. It never leaves your possession. 00:20:07.390 --> 00:20:10.130 And here's the magic part. How do they work together? 00:20:10.470 --> 00:20:12.730 The magic is the mathematical relationship between 00:20:12.730 --> 00:20:15.960 them. They're a matched pair. And the rule is 00:20:15.960 --> 00:20:19.279 this. Whatever is scrambled or encrypted by the 00:20:19.279 --> 00:20:22.519 public key can only be unscrambled by its one 00:20:22.519 --> 00:20:27.160 unique corresponding private key. Okay. So let's 00:20:27.160 --> 00:20:28.779 play this out. I want to send you a secret message. 00:20:29.220 --> 00:20:31.920 What do I do? Okay. You look up my public key. 00:20:32.119 --> 00:20:34.539 It's in a public phone book, let's say. You use 00:20:34.539 --> 00:20:36.420 that public key to lock your message. Okay. The 00:20:36.420 --> 00:20:38.279 message is locked. Now, can I unlock it with 00:20:38.279 --> 00:20:42.240 that same public key? No. Even you, the person 00:20:42.240 --> 00:20:44.980 who wrote it, cannot unlock it. Once it is locked 00:20:44.980 --> 00:20:47.059 with my public key, the only thing in the entire 00:20:47.059 --> 00:20:49.640 universe that can unlock it is my private key. 00:20:49.740 --> 00:20:51.700 And since you are the only one who has your private 00:20:51.700 --> 00:20:54.440 key? Only I can read the message. That is brilliant. 00:20:54.740 --> 00:20:56.920 Yeah. It solves the distribution problem completely. 00:20:57.319 --> 00:20:59.500 Completely. We don't need to meet in a dark alley 00:20:59.500 --> 00:21:01.980 to exchange keys. I just use the key you give 00:21:01.980 --> 00:21:04.680 to the whole world. Exactly. If an eavesdropper 00:21:04.680 --> 00:21:06.799 is listening in and they grab my public key, 00:21:06.940 --> 00:21:10.789 who cares? The public key is useless for reading 00:21:10.789 --> 00:21:13.089 messages. They can't use it to decrypt anything. 00:21:13.349 --> 00:21:15.250 All they can do is write me a secure message 00:21:15.250 --> 00:21:17.769 of their own. It's so elegant. It completely 00:21:17.769 --> 00:21:20.329 removes the need for the courier with the briefcase. 00:21:20.569 --> 00:21:23.430 It does. And it did something else, too. Something 00:21:23.430 --> 00:21:25.970 just as important. It enabled something called 00:21:25.970 --> 00:21:28.769 digital signatures. Right, because the math works 00:21:28.769 --> 00:21:31.490 in reverse, too. Yes. This is the other side 00:21:31.490 --> 00:21:34.230 of the coin. Think about it. If I encrypt something 00:21:34.230 --> 00:21:36.930 with my private key... The one only you have. 00:21:37.049 --> 00:21:39.690 Right. If I lock it with my private key, then 00:21:39.690 --> 00:21:42.170 anyone can decrypt it with my public key, since 00:21:42.170 --> 00:21:45.049 that key is public. But wait, if anyone can decrypt 00:21:45.049 --> 00:21:47.349 it, it's not a secret. What's the point? Correct. 00:21:47.529 --> 00:21:49.470 It's not about secrecy in this case. It's about 00:21:49.470 --> 00:21:53.049 authenticity. Authenticity? How so? If you can 00:21:53.049 --> 00:21:55.670 successfully unlock the message using my public 00:21:55.670 --> 00:21:58.650 key, that is a mathematical proof that it must 00:21:58.650 --> 00:22:00.549 have been locked by my private key. Because the 00:22:00.549 --> 00:22:03.210 keys are a matched pair. One can't work without 00:22:03.210 --> 00:22:06.119 the other. Exactly. And since I'm the only person 00:22:06.119 --> 00:22:09.420 in the world who has my private key, it proves 00:22:09.420 --> 00:22:12.099 that I was the one who sent the message. It's 00:22:12.099 --> 00:22:14.940 a signature that is impossible to forge. So this 00:22:14.940 --> 00:22:17.200 solves the identity problem. It proves who sent 00:22:17.200 --> 00:22:18.960 the message and that it hasn't been tampered 00:22:18.960 --> 00:22:21.539 with. Which is the foundation for every secure 00:22:21.539 --> 00:22:24.579 financial transaction we do today. When you go 00:22:24.579 --> 00:22:27.259 to your bank's website, your browser is checking 00:22:27.259 --> 00:22:29.059 a digital signature to make sure you're talking 00:22:29.059 --> 00:22:31.819 to the real bank and not a fake site set up by 00:22:31.819 --> 00:22:34.269 a scammer. The source quotes Stephen Levy saying 00:22:34.269 --> 00:22:36.410 from the moment Diffie and Hellman published 00:22:36.410 --> 00:22:39.309 their findings, the National Security Agency's 00:22:39.309 --> 00:22:42.089 crypto monopoly was effectively terminated. It 00:22:42.089 --> 00:22:44.490 was a massive power shift. The quote continues. 00:22:44.750 --> 00:22:47.309 Every company, every citizen now had routine 00:22:47.309 --> 00:22:49.509 access to the sorts of cryptographic technology 00:22:49.509 --> 00:22:52.650 that not many years ago rank alongside the atom 00:22:52.650 --> 00:22:55.670 bomb as a source of power. That's a heavy comparison. 00:22:56.009 --> 00:22:59.029 Alongside the atom bomb. Is that hyperbole? I 00:22:59.029 --> 00:23:01.289 don't think so. Think about it. During the Cold 00:23:01.289 --> 00:23:05.109 War. Power was defined by two things. Who had 00:23:05.109 --> 00:23:07.190 the biggest weapons and who had the best secrets? 00:23:07.589 --> 00:23:10.009 The government controlled the weapons, and through 00:23:10.009 --> 00:23:12.970 the NSA, they controlled the secrets. Diffie 00:23:12.970 --> 00:23:15.009 and Hellman basically published the blueprints 00:23:15.009 --> 00:23:17.549 and said, here is the math. Now everyone can 00:23:17.549 --> 00:23:20.250 have secrets. They democratized privacy. They 00:23:20.250 --> 00:23:22.670 did. And as you can imagine, the people who previously 00:23:22.670 --> 00:23:25.569 held that monopoly on power, the government, 00:23:25.690 --> 00:23:28.730 the NSA, they were not thrilled. Oh, I bet. They 00:23:28.730 --> 00:23:30.750 didn't just send a thank you card in a fruit 00:23:30.750 --> 00:23:33.089 basket. Not even close. And that leads us directly 00:23:33.089 --> 00:23:36.150 to the battle for standards, Section 5. This 00:23:36.150 --> 00:23:38.750 is where the theory hits the real world politics. 00:23:38.970 --> 00:23:41.329 This is where it gets nasty. So around 1975, 00:23:41.690 --> 00:23:43.849 1976, at the same time they're publishing their 00:23:43.849 --> 00:23:46.630 work, the National Bureau of Standards. or NBS 00:23:46.630 --> 00:23:49.029 proposes something called the Data Encryption 00:23:49.029 --> 00:23:52.549 Standard, DES. Right. The government realized 00:23:52.549 --> 00:23:54.490 that computers were becoming common in business 00:23:54.490 --> 00:23:57.730 and companies needed a way to encrypt data for, 00:23:57.809 --> 00:23:59.970 you know, payroll, trade secrets, things like 00:23:59.970 --> 00:24:02.269 that. So they proposed a standard system for 00:24:02.269 --> 00:24:05.029 everyone to use. And Diffie and Hellman looked 00:24:05.029 --> 00:24:07.509 at this proposal and said, wait a minute, this 00:24:07.509 --> 00:24:10.809 is broken. Specifically, they criticized the 00:24:10.809 --> 00:24:16.329 key length. DES used a 56 -bit key. Now, for 00:24:16.329 --> 00:24:19.410 the non -math folks out there, why was 56 bits 00:24:19.410 --> 00:24:21.789 a problem? What does that even mean? It was too 00:24:21.789 --> 00:24:24.769 short. In cryptography, the length of the key 00:24:24.769 --> 00:24:26.890 determines how many possible combinations there 00:24:26.890 --> 00:24:30.200 are. A longer key means exponentially more combinations. 00:24:30.519 --> 00:24:32.539 And more combinations means it's harder to guess. 00:24:32.859 --> 00:24:35.680 Exactly. Diffie and Hellman argue that a 56 -bit 00:24:35.680 --> 00:24:38.140 key was vulnerable to what's called a brute force 00:24:38.140 --> 00:24:40.339 attack. Which means just trying every single 00:24:40.339 --> 00:24:42.880 possible combination until you get lucky. Exactly. 00:24:42.960 --> 00:24:45.500 If the key is short enough, a powerful enough 00:24:45.500 --> 00:24:47.500 computer can just cycle through every option. 00:24:47.559 --> 00:24:50.779 Is it A? Is it B? Is it AA? Is it AB? In a reasonable 00:24:50.779 --> 00:24:53.019 amount of time. And they did the math. They figured 00:24:53.019 --> 00:24:54.579 out how much it would cost to build a machine 00:24:54.579 --> 00:24:57.009 to do it. And they thought the NSA knew this, 00:24:57.130 --> 00:25:00.089 that they proposed a weak standard on purpose. 00:25:00.410 --> 00:25:02.569 Oh, they were sure of it. They argued that the 00:25:02.569 --> 00:25:04.769 NSA wanted a standard that was just strong enough 00:25:04.769 --> 00:25:07.170 to stop, you know, corporate spies or low -level 00:25:07.170 --> 00:25:09.250 hackers. But not strong enough to stop the NSA. 00:25:09.509 --> 00:25:12.150 But weak enough that the NSA themselves, with 00:25:12.150 --> 00:25:14.869 their massive government -funded supercomputers, 00:25:14.930 --> 00:25:17.799 could crack it whenever they wanted to. That's 00:25:17.799 --> 00:25:20.319 a serious accusation. They were accusing the 00:25:20.319 --> 00:25:23.220 government of deliberately sabotaging the security 00:25:23.220 --> 00:25:25.339 of the American public for their own surveillance 00:25:25.339 --> 00:25:27.680 purposes. It was. It was a huge controversy. 00:25:27.940 --> 00:25:30.140 And there is actual evidence of the tension. 00:25:30.720 --> 00:25:33.180 There's a surviving audio recording of a review 00:25:33.180 --> 00:25:37.680 at Stanford in 1976. It involved Diffie, Hellman, 00:25:37.819 --> 00:25:40.619 and representatives from the NSA who flew out 00:25:40.619 --> 00:25:42.859 to meet them. What happened on the tape? What 00:25:42.859 --> 00:25:45.400 can you hear? You can hear the argument. You 00:25:45.400 --> 00:25:47.559 can hear Diffie and Hellman sketching out on 00:25:47.559 --> 00:25:50.960 a chalkboard how a massively parallel key cracker 00:25:50.960 --> 00:25:53.819 could be built. They're basically giving a blueprint 00:25:53.819 --> 00:25:56.099 for a machine that could break the government's 00:25:56.099 --> 00:25:58.599 own proposed code. They were taunting them. They 00:25:58.599 --> 00:26:01.019 were. They were saying, look, if we two guys 00:26:01.019 --> 00:26:03.200 at a university can design this on a chalkboard, 00:26:03.319 --> 00:26:05.619 a determined state actor or a big corporation 00:26:05.619 --> 00:26:08.220 can build it. This is not secure. And were they 00:26:08.220 --> 00:26:10.480 right? Did history prove them right? They were 00:26:10.480 --> 00:26:14.160 100 percent right. We learned later through declassified 00:26:14.160 --> 00:26:17.240 documents and reporting that the NSA did actively 00:26:17.240 --> 00:26:19.359 intervene with IBM, who designed the algorithm 00:26:19.359 --> 00:26:23.619 to shorten the key size from, I think, 128 bits 00:26:23.619 --> 00:26:26.880 down to 56. Wow. So it wasn't a conspiracy theory. 00:26:26.940 --> 00:26:30.000 It was a conspiracy fact. It was. They deliberately 00:26:30.000 --> 00:26:32.500 engineered the weakness, just as Diffie and Hellman 00:26:32.500 --> 00:26:35.740 suspected. And years later, when technology advanced, 00:26:36.079 --> 00:26:38.720 people built exactly the kind of machines they 00:26:38.720 --> 00:26:41.480 warned about. In the 90s, the Electronic Frontier 00:26:41.480 --> 00:26:45.619 Foundation, the EFF, built the EFF DES cracker. 00:26:45.640 --> 00:26:47.779 And did it work? It worked perfectly. It cracked 00:26:47.779 --> 00:26:49.819 the DES key in a matter of days, then hours. 00:26:50.079 --> 00:26:53.099 It proved, publicly and decisively, that DES 00:26:53.099 --> 00:26:56.319 was insecure and obsolete. Diffie was vindicated 00:26:56.319 --> 00:26:58.640 completely. It really highlights that David versus 00:26:58.640 --> 00:27:00.700 Goliath theme we talked about. He stood up to 00:27:00.700 --> 00:27:03.059 the NSA and IBM, too, of the most powerful organizations 00:27:03.059 --> 00:27:06.099 on the planet and said, your math is weak. He 00:27:06.099 --> 00:27:08.200 was right. It takes a lot of confidence and a 00:27:08.200 --> 00:27:10.519 lot of courage to do that. Remember, he was young. 00:27:10.539 --> 00:27:12.359 He wasn't a tenured professor with a Nobel Prize 00:27:12.359 --> 00:27:14.740 yet. He was just a guy with part time research 00:27:14.740 --> 00:27:17.150 grant and a conviction that he was right. So 00:27:17.150 --> 00:27:20.549 after these massive, world -changing breakthroughs 00:27:20.549 --> 00:27:23.390 in the 70s, Diffie moves out of the purely academic 00:27:23.390 --> 00:27:26.210 sphere and into the corporate world. What did 00:27:26.210 --> 00:27:30.170 his later career look like? From 1978 to 1991, 00:27:30.609 --> 00:27:33.470 he worked at Northern Telecom. He was the manager 00:27:33.470 --> 00:27:36.170 of secure systems research. Northern Telecom. 00:27:36.210 --> 00:27:38.690 That's big infrastructure stuff. Telecommunications. 00:27:38.750 --> 00:27:41.230 Exactly. He was designing key management architecture 00:27:41.230 --> 00:27:44.630 for the PDSO security system on X .25 networks. 00:27:44.990 --> 00:27:47.190 OK, you've got to translate that for us. Laughing. 00:27:47.650 --> 00:27:49.849 Basically, he was figuring out how to implement 00:27:49.849 --> 00:27:53.069 his ideas to secure the phone lines and the early 00:27:53.069 --> 00:27:54.930 data networks that were starting to span the 00:27:54.930 --> 00:27:58.299 globe. He was taking his theoretical split key 00:27:58.299 --> 00:28:01.200 idea and making it work in the messy real world 00:28:01.200 --> 00:28:03.559 of cables and switches and routers. Making it 00:28:03.559 --> 00:28:05.940 practical. Making it practical at a massive scale. 00:28:06.140 --> 00:28:09.640 And then in 1991, he joined Sun Microsystems. 00:28:09.640 --> 00:28:12.039 Which was a huge move. Sun was, I mean, it was 00:28:12.039 --> 00:28:13.900 the Google of the 90s. They were the company 00:28:13.900 --> 00:28:15.799 building the servers and workstations that ran 00:28:15.799 --> 00:28:18.220 the early internet. Their motto was, the network 00:28:18.220 --> 00:28:20.720 is the computer. And what was his role there? 00:28:20.839 --> 00:28:23.339 It wasn't just engineer, right? No. He had several 00:28:23.339 --> 00:28:25.519 titles over the years. Distinguished Engineer, 00:28:25.859 --> 00:28:28.680 Vice President, and Chief Security Officer. Eventually, 00:28:28.700 --> 00:28:31.039 he was made a Sun Fellow. Which sounds like a 00:28:31.039 --> 00:28:33.640 very high honor within the company. It is. It's 00:28:33.640 --> 00:28:35.759 the highest technical rank you can achieve. It 00:28:35.759 --> 00:28:38.640 means you're basically a guru who gets to work 00:28:38.640 --> 00:28:41.660 on whatever you think is important. But at Sun, 00:28:41.859 --> 00:28:44.359 his role shifted a bit. He started focusing a 00:28:44.359 --> 00:28:46.980 lot on the public policy aspects of cryptography. 00:28:47.220 --> 00:28:49.880 How so? What does that mean? He wasn't just coding 00:28:49.880 --> 00:28:53.059 anymore or designing systems. He became the chief 00:28:53.059 --> 00:28:56.200 exponent of Sun's security vision. He was testifying 00:28:56.200 --> 00:28:58.660 before Congress. He was fighting the crypto wars 00:28:58.660 --> 00:29:01.279 of the 90s. The crypto wars? Yeah, that was the 00:29:01.279 --> 00:29:02.880 period when the government tried to ban strong 00:29:02.880 --> 00:29:05.599 encryption or force companies to install backdoors 00:29:05.599 --> 00:29:08.599 for law enforcement. Diffie was on the front 00:29:08.599 --> 00:29:11.440 lines explaining to lawmakers and the world why 00:29:11.440 --> 00:29:14.339 strong, unbreakable security mattered for privacy, 00:29:14.559 --> 00:29:17.539 for commerce, and for democracy itself. So he 00:29:17.539 --> 00:29:19.720 became a statesman for the cause. A statesman 00:29:19.720 --> 00:29:22.180 for privacy, yes. A public intellectual. He stayed 00:29:22.180 --> 00:29:25.420 there until 2009. And after Sun. He didn't just 00:29:25.420 --> 00:29:28.460 retire. No, not his style. He did a stint at 00:29:28.460 --> 00:29:30.220 ICANN, the Internet Corporation, for assigned 00:29:30.220 --> 00:29:33.809 names and numbers from 2010 to 2012. He was their 00:29:33.809 --> 00:29:36.450 vice president for information security and cryptography. 00:29:36.690 --> 00:29:39.210 ICANN is the organization that manages the address 00:29:39.210 --> 00:29:41.599 book of the Internet, right? Domain names and 00:29:41.599 --> 00:29:44.759 IP addresses. Exactly. So he went from inventing 00:29:44.759 --> 00:29:47.039 the lock to helping design the building to helping 00:29:47.039 --> 00:29:49.599 secure the entire city's street plan. He kept 00:29:49.599 --> 00:29:51.579 his foot in academia, too, I think. Oh, yes. 00:29:51.799 --> 00:29:54.079 He never really left it. He had visiting professor 00:29:54.079 --> 00:29:56.440 roles at Royal Holloway at the University of 00:29:56.440 --> 00:29:58.960 London, which has a premier security group. He 00:29:58.960 --> 00:30:01.140 was a visiting scholar back at Stanford. And 00:30:01.140 --> 00:30:03.140 he even took a role at the Jiang University in 00:30:03.140 --> 00:30:06.299 China in 2018. He's a global citizen of the security 00:30:06.299 --> 00:30:09.539 world. He's a legend. And fittingly, the world 00:30:09.539 --> 00:30:12.519 eventually... officially recognized just how 00:30:12.519 --> 00:30:15.059 monumental his contributions were. The awards 00:30:15.059 --> 00:30:17.960 list is staggering. But the big one, the crown 00:30:17.960 --> 00:30:22.339 jewel, came in 2015. The Turing Award. Yes. He 00:30:22.339 --> 00:30:24.500 won it jointly with his old partner, Martin Hellman. 00:30:24.660 --> 00:30:27.240 And as we said, it is considered the Nobel Prize 00:30:27.240 --> 00:30:29.000 of Computing. It's the highest honor in the field. 00:30:29.339 --> 00:30:32.759 And the citation for the award just it sums it 00:30:32.759 --> 00:30:35.740 all up perfectly. It does. It says it's for introducing 00:30:35.740 --> 00:30:38.539 the ideas of public key cryptography and digital 00:30:38.539 --> 00:30:41.299 signatures, the foundation of modern Internet 00:30:41.299 --> 00:30:44.019 security protocols. There is no ambiguity there. 00:30:44.119 --> 00:30:46.420 They built the foundation. He was also inducted 00:30:46.420 --> 00:30:49.180 into the National Inventors Hall of Fame in 2011, 00:30:49.500 --> 00:30:51.559 named a fellow of the Computer History Museum. 00:30:51.700 --> 00:30:54.539 And this is a big one. Elected a foreign member 00:30:54.539 --> 00:30:57.579 of the Royal Society in 2017. That's the Academy 00:30:57.579 --> 00:31:00.660 of Newton and Darwin. Not bad for a guy who refused 00:31:00.660 --> 00:31:02.839 to take his high school regents exams because 00:31:02.839 --> 00:31:04.579 he thought they were a waste of time. Not bad 00:31:04.579 --> 00:31:07.240 at all. Kind of validates his path, doesn't it? 00:31:07.279 --> 00:31:09.259 He knew what he was good at and he knew it mattered 00:31:09.259 --> 00:31:11.680 and he just ignored the rest. So as we wrap this 00:31:11.680 --> 00:31:14.109 up, let's go back to the man himself. We described 00:31:14.109 --> 00:31:18.269 him as an iconoclast, a pacifist, a rebel. What 00:31:18.269 --> 00:31:20.910 was his driving philosophy? He stated once that 00:31:20.910 --> 00:31:23.509 he was always concerned about individuals and 00:31:23.509 --> 00:31:25.869 individuals' privacy as opposed to government 00:31:25.869 --> 00:31:28.509 secrecy. And that's it in a nutshell. That is 00:31:28.509 --> 00:31:30.750 his core philosophy. He believed that regular 00:31:30.750 --> 00:31:32.890 people should have the ability to keep their 00:31:32.890 --> 00:31:36.390 conversations private, even from the state. that 00:31:36.390 --> 00:31:38.650 it's a fundamental right. It's a powerful legacy. 00:31:38.930 --> 00:31:41.410 I mean, every time we send secure message on 00:31:41.410 --> 00:31:43.950 WhatsApp, every time we log into our bank, every 00:31:43.950 --> 00:31:46.329 time we see that little padlock icon in the URL 00:31:46.329 --> 00:31:49.490 bar of our browser, we are using the tools he 00:31:49.490 --> 00:31:52.029 fought for. We are. He shifted the balance of 00:31:52.029 --> 00:31:54.430 power. He took the atom bomb of information power 00:31:54.430 --> 00:31:57.210 away from the generals and the spy agencies and 00:31:57.210 --> 00:31:59.440 gave it to the people. But this brings me to 00:31:59.440 --> 00:32:01.019 a final provocative thought, and I want to get 00:32:01.019 --> 00:32:03.680 your take on this. Diffie's dream, his whole 00:32:03.680 --> 00:32:06.559 goal, was to eliminate the trusted third party. 00:32:06.740 --> 00:32:08.980 Right. Peer -to -peer trust. Guaranteed by math. 00:32:09.200 --> 00:32:11.640 But look at the internet today. We rely on Google 00:32:11.640 --> 00:32:14.299 for our email, Facebook for our social lives, 00:32:14.460 --> 00:32:16.640 Amazon for our shopping, Apple for our phones. 00:32:16.859 --> 00:32:19.160 We rely on certificate authorities to tell us 00:32:19.160 --> 00:32:21.980 a website is safe. We rely on VPN providers to 00:32:21.980 --> 00:32:24.220 hide our traffic. That is the great irony of 00:32:24.220 --> 00:32:26.519 the modern web, isn't it? Have we truly achieved 00:32:26.519 --> 00:32:29.630 the privacy diff - envisioned? Or have we just 00:32:29.630 --> 00:32:32.509 traded one set of trusted third parties, the 00:32:32.509 --> 00:32:35.250 government, for another, arguably just as powerful 00:32:35.250 --> 00:32:38.470 set, the tech giants? That is the billion dollar 00:32:38.470 --> 00:32:40.730 question. And I think it's a really sharp point. 00:32:40.930 --> 00:32:43.369 Divi gave us the tools for independence. The 00:32:43.369 --> 00:32:46.769 math works. The math is perfect. But the implementation, 00:32:47.089 --> 00:32:50.049 the systems we built on top of that math, has 00:32:50.049 --> 00:32:52.799 often led us right back to centralization. We 00:32:52.799 --> 00:32:55.240 still tend to trust giant entities to hold our 00:32:55.240 --> 00:32:58.140 keys, manage our data, and mediate our communications. 00:32:58.740 --> 00:33:01.140 It seems like human nature craves a middleman. 00:33:01.200 --> 00:33:03.700 Even if the math says we don't need one, we want 00:33:03.700 --> 00:33:06.500 convenience. Perhaps. Or perhaps the fight isn't 00:33:06.500 --> 00:33:08.920 over. Diffie gave us the sword. It's up to us 00:33:08.920 --> 00:33:11.039 to decide how to use it. The struggle between 00:33:11.039 --> 00:33:14.819 centralization and decentralization is the defining 00:33:14.819 --> 00:33:16.900 struggle of the digital age. Something to think 00:33:16.900 --> 00:33:18.819 about the next time you unlock your phone. It's 00:33:18.819 --> 00:33:22.170 secure, sure. But... Who holds the keys? Indeed. 00:33:22.349 --> 00:33:24.410 That's it for this deep dive into the life of 00:33:24.410 --> 00:33:26.269 Whitfield Diffie. Thanks for listening, and we'll 00:33:26.269 --> 00:33:26.930 catch you next time.