ACM A.M. Turing Award Recipients Whitfield Diffie and Martin Hellman discuss their revolutionary encryption technology. See "The Key to Privacy" (cacm.acm.org/magazines/2016/6/202654) in the June 2016 CACM.
00:00 MARTIN HELLMAN: People often say Whit was my student. But what I've said about Whit is, Whit can be no-one's student. And I think you would agree.
00:07 WHITFIELD DIFFIE: Yeah, well, I'm not very good at it. I admire people who are good students. I think it's [a] tremendously valuable skill. I just have never proved very good at it. [DR. HELLMAN laughs]
00:15 [OVERLAY: Recipients, 2015 ACM A.M. Turing Award]
00:18 [Intro graphics/music]
00:27 "We stand today on the brink of a revolution in cryptography." With these words, Whitfield Diffie and Martin Hellman opened the 1976 paper in which they introduced public-key cryptography to the world.
00:42 DIFFIE: We sit in public and negotiate and come out with a secret, and none of the observers who've heard every bid and response knows what the secret is. So that's what the Diffie-Hellman key exchange does.
00:58 The field in 1976 was largely unknown outside of secret research at government agencies, such as the one where Alan Turing himself once worked as a cryptographer.
01:08 HELLMAN: When I started working in cryptography, in the late '60s / early '70s, even before I met you, my colleagues uniformly told me I was crazy to work in it.
01:18 By 1974, Martin Hellman had established himself as a Professor of Electrical Engineering at Stanford University. His students there included Ralph Merkle, whose work contributed to their 1976 paper. But Whitfield Diffie followed another path.
01:36 HELLMAN: When I met you, you were traveling around the country as an itinerant cryptographer, living on whatever you'd saved up and the largesse of the AI community, which seems to bunk people free of charge if they like you. [laughs]
01:51 DIFFIE: What happened was that I got interested in cryptography, and so did several other people who did some significant things. But their interest lasted a month or something like that. Six months later, I was thinking about nothing else.
02:06 Their first half-hour meeting stretched into the night, and Whitfield Diffie decided to remain at Stanford. There they were a formidable team.
02:16 DIFFIE: I think Marty is smarter than I am and I'm more imaginative than he is. And so in our working relationship, I came up with more problems and he came up with more answers.
02:27 Together they exposed a government plan to gain access to encrypted secrets by weakening the proposed Digital Encryption Standard. Their arguments were proven right -- and they struck a blow for academic freedom as well.
02:40 HELLMAN: There was this belief within NSA that they had control over our ability to publish our papers, because they were being exported when they were published in international journals.
02:53 Dr. Diffie finished a career at Sun Microsystems and now advises startups, while since the '80s Dr. Hellman has focused on deterring threats of nuclear war. But their remarkable work making cryptography available for the masses lives on.
03:08 MICHAEL I. JORDAN: When you teach it, it's [a] wonderful little story. You can set up the story, you can make people think it's not possible, then show them it is. And that's a very striking thing to be able to do.
03:17 ALEX AIKEN: They caused a revolution. There was a way of doing cryptography that had been done for centuries ... And then they came along and really introduced a new way of thinking about it and opened up a whole new realm of possibilities. And they told the world about it.
03:34 The Association for Computing Machinery sincerely thanks Whitfield Diffie and Martin Hellman for all they've done. We feature their life and work in the June 2016 issue of Communications of the ACM. A banquet in San Francisco celebrates them, along with recipients of this year's other ACM awards.
03:54 [Outro and credits]