In a double dose of irony, the National Security Agency's prying has given a big helping hand to Phil Zimmermann's business, Silent Circle.
The first irony is that Zimmermann was the very person the US federal government fought with in the 1990s over the release of the software called PGP, short for Pretty Good Privacy, which made encryption much easier to use. The second irony is that he's now president and co-founder of Silent Circle, a company that seeks to profit from making it harder for the NSA or anybody else to find out what people are saying on phone calls, with text messages, and over Internet video chat.
Recent revelations about the NSA gathering information using data taps on the Internet, phone call metadata, encryption cracking, and subpoenas of large Internet companies has helped Silent Circle's business. "It's been just huge," Zimmermann said in interview.
It's also been sobering. Silent Circle scrapped its Silent Mail product in August after concluding that even without government subpoenas, e-mail inherently broadcasts lots of private information.
Silent Circle would be hard to classify as a government adversary, though. US, UK, and Canadian government and military organizations including the CIA are customers, Zimmermann said, and company co-founder Mike Janke is a former US Navy SEAL sniper.
Zimmermann, 59, rose to Internet fame with PGP, which lets people send each other encrypted messages using public-key cryptography. With that technology, a person can send a private message to a recipient by encrypting it with the recipient's public key. In addition, a sender can use PGP as a sort of digital signature by encrypting a message with the sender's own private key; the recipient can then confirm the sender's identity by decrypting the message with the sender's public key. The US government initially had argued that Zimmermann violated export controls by publishing the software on the Internet, but it eventually dropped the case against him in 1996.
Zimmermann wrote PGP in the firm belief that people are entitled to privacy, but PGP technology has a hard time staying relevant. It works as a plug-in to PC-based e-mail software, but it's not compatible with Web-based services such as Gmail or with standard mobile-phone e-mail apps. In recent years, Zimmermann worked on securing VOIP (voice over Internet Protocol) communications, and Janke and Zimmermann publicly launched Silent Circle in 2012.
Zimmermann spoke to CNET's Stephen Shankland after the Open-Xchange Summit in Hamburg, Germany, on Sept. 26. Here's an edited transcript of his interview.
You're much more sophisticated than the average Internet user. Were you surprised by anything Edward Snowden revealed about the NSA?
I was surprised because of the enormous scale of what he revealed. I knew the NSA had powerful capabilities, but I didn't know they were this comprehensive in their scope. It's kind of breathtaking. I've talked about this and written about it for more than 20 years. I feel like my most pessimistic projections had fallen short of reality.
Has this had any effect on people's concern for privacy, or has it already blown over?
It has driven sales quite a bit. We're making a lot more money now than we did before. So I guess I should be happy. But i'm not happy, of course, because I'm really concerned about our democratic institutions. I think this vast surveillance infrastructure is an irresistible temptation to an abuse of power.
And we've now seen evidence of that with the current surveillance?
Without impugning the motives of the people who designed it, in the previous or current administration, we could say we don't know who's going to be in the White House in 2017. Are they going to have the moral sensibilities of Thomas Jefferson or of Vladimir Putin? What could they do with a surveillance apparatus this vast? Eventually we're going to have somebody in White House who might like to have that omniscience, but for a very selfish purpose.
How do you see the relevance of your software in light of the NSA's surveillance?
I've always tried to design my protocols to be able to resist the NSA as an opponent. I feel good that with the revelations we've seen about the NSA being able to break so much crypto out there, conspicuously absent from the list is anything designed by me. That warms my heart.
For a long time I wanted to pull the plug on Silent Mail. We only had it in there because there was customer demand for it. We just weren't happy with the architecture. We didn't have any PGP client for the smartphones, and it would take a long time to develop one. We didn't want to wait with what we had, which was secure VOIP and secure text messaging. For Silent Mail, we were [using] a very nice server product called PGP Universal [now called Symantec Encryption Management Server after Symantec acquired Zimmermann's earlier company]. The problem is that the keys reside on the server. That works well with a monolithic company IT department managing everyone's key, but doesn't work so well for a service provider like us with a bunch of public users. It was an attractive nuisance.
It gave customers a false sense of security?
By having all those keys on a server, we were inviting trouble. Even without the keys, it would have still been a problem because all the metadata is there. All the e-mail protocols expose data -- from, to, subject line, date, the IP addresses where it's coming from and going to. Who you're talking to can matter more than what you say.
Any way you cut it, the security properties of our e-mail was not anywhere near as good as the security properties of secure telephony and secure instant messaging.
You've wrestled with the feds before. What do they think of you now, selling encryption products?
They use my stuff now, so I'm hoping they would leave me alone. They've been using PGP for more than a decade, but they use my new stuff quite a bit.
From Silent Circle?
Yeah. We're used by the Navy SEALs and the Central Intelligence Agency, some law enforcement agencies, the British special-ops guys, the SAS, and the Canadian special ops guys.
We've created this situation where I don't think we have to worry about them asking us to put a back door in [letting the government get access to communications as easily as tapping analog phone lines] because there would be collateral damage. We would refuse, but I don't have to worry about it because they're never going to ask. Any back door would hurt them equally.
There's always been a tradeoff pitting security against convenience. How does the arrival of Web-based e-mail and the profusion of mobile devices affect PGP and secure communications?
We realized straight away that we couldn't effectively bring a PGP client to market for mobile devices. There are too many devices. We don't have PGP for iOS and Android, and it would take us too long to put together. It would keep us out of the market for a long time.
What we really wanted to do was secure VOIP and text messaging. Secure e-mail was something we regarded as a secondary priority and one we could address later with something new on the client for mobile devices.
In the old days, you could use PGP on the personal computer where you had your e-mail. But today, I have four PCs, two phones, and two
tablets, so that's just not possible.
When I first introduced PGP in the 1990s, you could encrypt a file and send it by e-mail pretty easily. Today, what can you do? The mail client running on the iPhone -- Apple controls that, and they're not going to do any plug-ins. You have to write a whole new e-mail client. Not only would we have to write a new PGP client, we'd have to write an e-mail client. That's the only way. That's a big barrier to entry.
So what other technologies should people use for secrurity? VOIP services, Skype...
Don't use Skype. VOIP and IM are fun interesting technologies. VOIP is where I put my attention over the last few years. I've done several clients over the years. PGP phone in 1995, part of one in Java in 2001, then I did a couple more during the Zphone project, then we did this one here [at Silent Circle]. This is the best one I've done.
I used PGP years ago, but even then only for a small fraction of communications. What's your forecast -- will the NSA revelations get people to care more about their privacy?
One NSA document said to give special attention to encrypted traffic. What we need here is an "I am Spartacus" moment. Everybody has to use crypto, to show solidarity.
To show that ordinary people use encryption, not just people with something to hide, you mean. Will it ever happen?
The question of predicting the future is the wrong approach to take. We don't passively sit on the sidelines and watch the World Series. We're the baseball players. The best way to predict the future is to create the future -- to say what the future you want is, and then work to get there.