Encryption in spotlight
Lesson drawn from WikiLeaks’ CIA release
NEW YORK — If the tech industry is drawing one lesson from the latest WikiLeaks disclosures, it’s that data-scrambling encryption works, and the industry should use more of it, experts said.
Documents purportedly outlining a vast CIA surveillance program suggest that CIA agents must go to great lengths to circumvent encryption they can’t break. In many cases, physical presence is required to carry off these targeted attacks.
“We are in a world where if the U.S. government wants to get your data, they can’t hope to break the encryption,” said Nicholas Weaver, who teaches networking and security at the University of California, Berkeley. “They have to resort to targeted attacks, and that is costly, risky and the kind of thing you do only on targets you care about. Seeing the CIA have to do stuff like this should reassure civil libertarians that the situation is better now than it was four years ago.”
Four years ago, former National Security Agency contractor Edward Snowden revealed details of secret U.S. eavesdropping programs. To help thwart spies and snoops, the tech industry began to protectively encrypt email and messaging apps, a process that turns their contents into indecipherable gibberish without the coded keys that can unscramble them.
The NSA revelations shattered earlier assumptions that Internet data was nearly impossible to intercept for meaningful surveillance, said Joseph Lorenzo Hall, chief technologist at the Washington-based civil-liberties group Center for Democracy and Technology. That was because any given Internet message gets split into a multitude of tiny “packets,” each of which traces its own unpredictable route across the network to its destination.
The realization that spy agencies had figured out that problem spurred efforts to better shield data as it transits the Internet. A few services such as Facebook’s WhatsApp followed the earlier example of Apple’s iMessage and took the extra step of encrypting data in ways even the companies couldn’t unscramble, a method called end-to-end encryption.
In the past, spy agencies like the CIA could have hacked servers at WhatsApp or similar services to see what people were saying. End-to-end encryption, though, makes that prohibitively difficult. So the CIA has to resort to tapping individual phones and intercepting data before it is encrypted or after it’s decoded.
It’s much like the old days, when “they would have broken into a house to plant a microphone,” said Steven Bellovin, a Columbia University professor who has long studied cybersecurity issues.
Cindy Cohn, executive director for Electronic Frontier Foundation, a group focused on online privacy, likened the CIA’s approach to “fishing with a line and pole rather than fishing with a driftnet.”
Encryption has grown so strong that the FBI had to seek Apple’s help last year in cracking the locked iPhone used by one of the San Bernardino Calif. attackers. Apple resisted what it considered an intrusive request, and the FBI ultimately broke into the phone by turning to an unidentified party for a hacking tool — presumably one similar to those the CIA allegedly had at its disposal.
Government officials have long wanted to force tech companies to build “back doors” into encrypted devices, so that the companies can help law enforcement descramble messages with a warrant. But security experts warn that doing so would undermine security and privacy for everyone. As Apple Chief Executive Officer Tim Cook pointed out last year, a back door for good guys can also be a back door for bad guys. So far, efforts to pass such a mandate have stalled.
And encryption isn’t a panacea, as the WikiLeaks disclosures suggest.
According to the purported CIA documents, spies have found ways to exploit holes in phone and computer software to grab messages when they haven’t been encrypted yet.
Cohn said people should still use encryption, even with these bypass techniques.
“It’s better than nothing,” she said. “The answer to the fact that your front door might be cracked open isn’t to open all your windows and walk around naked, too.”