Interview with Phil Zimmermann - Inventor of PGP (Page 2)
J: So what do you think the future holds for PGP and cryptography in general?
PZ: Well, I think that we're going to see more and more cryptography in all parts of our life. We are going to see it in telephones for example. That's something I'm working on right now. The ubiquity of cryptography will spread. Something that interests me also is that recently there's been a new interest in what happens to people who are doing travel, business travel and they are carrying their laptop computers with them and border control, border guards search their laptop computers and you know, when you're travelling, you could, in the old days, just decide what to put in your suitcase and just not put anything dangerous in your suitcase and they can't search your house when you're travelling but when you have a laptop computer now, all of your entire life is in your laptop computer. It's not just something you carry when you travel, it's something you use everyday for all your business and your personal life and if they can search that, thats severe undermining of civil liberties, its sort of like searching your house any time they want and so I think cryptography will become more important for protecting business travellers when they carry laptop computers with them and cross borders. Now when you what is the future of cryptography, I'm not giving you the future of cryptography. I'm just telling you about things that are interesting to me right now. I don't know what the future of cryptography is. The best way to predict the future is to create it.
J: Could you tell us a little about your latest zfone project?
PZ: Yeah. I've been interested in encrypting phone calls for longer than I have been interested in encrypting e-mails. I became interested in the early 1980s in encrypting phone calls, but the technology wasn't ready then. And then in the middle 1990s I implemented it with PGP phone but still the Internet wasn't ready. Nobody had broadband and there were no voIP standards. So now it's time to do it, because now we have voIP standards and now people do have broadband. It's time to encrypt Voice over IP and that's where I'm putting all of my psychic energy these days. If you look for the zfone project, zfone is spelt with an 'f' not a 'ph', and take a look at that website or go to my personal website philzimmermann.com spelling 'Zimmermann' the German way, with an extra 'n' in the end, and you'll find a link to zfone project website. I think that's a more fun application of public-key cryptography.
J: Alright! So I guess once the zfone is finally out we won't have to be worried about wire-tapping! Do you have any other future projects in mind?
PZ: Well, this for now is taking up all my attention. So I'm not really thinking of future projects right now. I'm just trying to make this one work as well as I can make it work. It's fun! It's exciting! It's phone calls! Phone calls are so much more interesting than e-mails. It's two human beings talking to each other. It's whispering in someone's ear from a thousand miles away.
J: Transforming an idea into a reality is tedious process. Were there are situations when you felt you almost hit a dead end while writing PGP?
PZ: Well, um... I think that the software engineering side of writing PGP wasn't that bad but, the legal obstacles were more formidable. It was not a friendly legal environment in the early 1990s. But now it's a friendly legal environment. Now, the legal systems are set up to encourage people to develop encryption software. However, these days software engineering is more complex - programs are bigger now. There's more code bloat. So it is more daunting now. In fact, I don't write code anymore. I've gotten too old for that. I now have to have other people write code for me.
J: We've been hearing a lot about quantum cryptography and how it could be used in a variety of applications like satellite communication. Could you tell us a little about that?
PZ: Well, quantum cryptography is a fun application of physics. It's fun! It's a neat trick with physics. It involves sending photons through optical fibres and being able to tell if somebody intercepts them along the way by using the properties of quantum mechanics to detect if the photon has been touched by someone along the way. But I think it's a solution looking for a problem. It's not necessary to do quantum cryptography because the kinds of public-key cryptography we've already got works just fine. Quantum cryptography can only be used in special physical circumstances over short fibre optic cables, may be a couple hundred kilometres, at the most. You can't put repeaters and it's not something you can use generally for... If you want to use the Internet to carry messages, your messages are gonna be carried over copper or fibre or microwave or Wifi or satellite or, you know, bongo drums! There's all kinds of physical media that can carry your messages and regular public-key cryptography doesn't care. But if you use quantum cryptography you can only carry it with fibre optics. You can only carry it in places where you can send photons and intercept the photons, I mean, not intercept them, but, you know, one party sends a photon to the other party and after that look at the photon and see if it's in quantum state you would expect it to be in and if nobody had touched it along the way. So it's cool physics. But it's not as practically useful as regular cryptography. In fact, it is not even cryptography at all. It's just a neat physics trick.
J: That was really interesting to hear, sir. To conclude, what is your advice for students who want to take up cryptography as their field of work? What are the specific skill sets that are required and what do you think they should take as courses in their college?
PZ: Well, I think, if you wanna take some courses in number theory, that would be useful, because a lot of the more interesting things that happened in cryptography relate to public-key cryptography and all the public-key algorithms in some form relate to number theory, finite fields, elliptic curves... Just getting a good math background is a good idea and software engineering! I think if you come up with that combination that's a good start. But you also have to develop a disciplined thinking. I'm not sure how much that's covered in the class rooms but you have to spend time attacking systems and understanding what their vulnerabilities are, understanding threat models, understanding the capabilities of your opponents. And that comes over time with practice.
J: Alright! I think our audience will find that useful a lot. So thank you for taking time off from your busy schedule to give us this interview, Mr. Zimmermann. It was really nice talking to you!
PZ: Well, thank you! I'm happy to be here!
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