GoDaddy Cancels Lavabit's Crypto Key

Digital certificate registrar GoDaddy has canceled the SSL key used by Lavabit to encrypt its 400,000 subscribers' email communications after Lavabit owner and operator Ladar Levison publicly revealed that he was forced to provide a copy of the key to the FBI.

Cue revocation. "We revoked all of the SSL certificates we were able to associate with Lavabit," GoDaddy spokeswoman Elizabeth L. Driscoll told InformationWeek via email. "We're compelled by industry policies to revoke certs when we become aware that the private key has been communicated to a third party and thus could be used by that party to intercept and decrypt communications," she recently told Forbes.

Levison initially resisted the FBI's demand that he give the agency a way to gather near-real time email header and routing information for an account used by former National Security Agency contractor Edward Snowden. Snowden's use of Lavabit was revealed when journalists on July 11 received an emailed invitation from "[email protected]" to a press conference at Moscow's Sheremetyevo airport.

On July 16, FBI agents visited Levison in Texas, carrying a subpoena authorizing them to install a pen register on Snowden's account. But Levison declined, arguing in court filings that giving the bureau the SSL key would then give it access to every one of his customer's communications. A judge, however, later overruled those objections, hitting Levison with a daily $5,000 fine after he printed out a copy of the key in four-point type, but wouldn't give the bureau a digital copy of the key.

[ How far can the FBI legally go with suspected computer criminals? Stratfor Hacker: FBI Entrapment Shaped My Case. ]

Rather than comply with the order, in August Levison shut down his service, thus making the FBI's attempted surveillance of Snowden's account moot. At the time, however, Levison was under a gag order concerning the subpoena, and thus could only announce the closure in broad terms to his customers. "I have been forced to make a difficult decision: to become complicit in crimes against the American people or walk away from nearly 10 years of hard work by shutting down Lavabit," he said in a statement posted to his website. "After significant soul searching, I have decided to suspend operations. I wish that I could legally share with you the events that led to my decision. I cannot."

Now, however, many of the documents related to Levison's legal battle with the Department of Justice have been unsealed. He's now fighting related civil contempt of court charges, and this week filed a brief seeking to overturn the court order compelling him to disclose the private SSL keys. "I want to set a precedent that government can't ask for SSL keys," Levison told Forbes last week. "It's the security tool that underpins the Internet."

After shutting down Lavabit, Levison established a legal defense fund that he said has already raised $200,000. But said he's now burned through half of that, defending himself in court.

But will Levison's legal bid succeed? In fact, George Washington University professor Orin Kerr, a former Department of Justice computer crime prosecutor, said in a blog post that Levison faces an "uphill battle."

"The government obtained several different court orders requiring Lavabit to disclose the key. First, they obtained a pen register order; next, they issued a subpoena for the key; and third, they obtained a search warrant for the key," Kerr said. "In order to win on appeal, Lavabit needs to show that all three methods are improper. I don't think they can do this."

The problem is that because Levison possessed the crypto keys, he would have needed to demonstrate to a judge that his need to not disclose the key outweighed the FBI's need to monitor a suspect as part of an ongoing criminal investigation. "There are things you can do which are more or less effective to protect this stuff, from a legal standpoint," said security lawyer Mark Rasch, a former federal computer crime prosecutor based in Bethesda, Md., speaking by phone. For example, when it comes to crypto keys, a U.S. website operator could trust a friend in a foreign country to hold the only copy of the key. That would force the FBI, if it came calling for the key, to liaise with its foreign counterparts to try and get a foreign court to require that the key be disclosed.

"But the best protection is to just not have it," Rasch said. For example, every customer could obtain and hold its own key, without ever giving a site administrator access to it.

Levison, however, did have the single crypto key that was able to unlock all Lavabit communications. "At the end of the day, what he did was to say I'm going to shut down the service, because he can't provide secure communications -- and can't tell people why," Rasch said. "And the government can't order him to continue to run the service. Of course, there's nothing to stop him from starting a brand-new service two days later, using the same technology, except this time with multiple keys that he doesn't hold."

Obviously, Levison's decision to shutter his business rather than give the FBI a copy of his crypto keys highlights the business and reputational pressure that Levison faced. Once the FBI had the digital certificate that was used to encrypt all Lavabit communications, it could have then intercepted any of its 400,000 subscribers' communications. "They could read more than emails, they could intercept usernames, passwords, credit card transactions that were going through my site, log-ins, as well as email and content. And [the FBI] told me in person that's what they wanted to do, they saw it as pursuing a criminal and they didn't really realize what rights they were treading on in order to do it," he told The New York Times last week.

"I said 'look, if I did this for you guys, it will destroy my business if anybody ever found out,'" Levison said. "They said nobody will ever find out, it's going to be kept secret. How well did that work out?"