Since Edward Snowden leaked information about NSA surveillance to the world, encryption has seen itself thrust in the spotlight, with Snowden himself emphasising that "encryption does work." Now, even household names like Google and Yahoo are jumping on the privacy bandwagon, and the promotion of end-to-end encryption by mainstream services is on the rise.
Google recently released an encryption extension for its Chrome browser that relies on the popular OpenPGP protocol, which can already be found in privacy technology used by journalists, hackers, and whistleblowers. The Chrome End-to-End extension aims to protect your communications while in transit, so that only the intended recipient can read them—even if they are, say, swept up in a mass surveillance program.
Soon after, Yahoo announced plans to implement similar protections by 2015. Myriad other, less well-known companies are pushing privacy in the wake of NSA revelations, too. Crowdfunded ProtonMail is aiming to provide email encryption that anyone can use, and the creator of Lavabit—which was used by Snowden—is setting up another service with Dark Mail.
"We're definitely seeing an uptick in companies' promotion of end-to-end encryption," Ashkan Soltani told me over email. Soltani is a privacy and security researcher who has recently been working with a Washington Post team to cover some of the biggest NSA stories. Although major firms are now promoting encryption, he pointed out that whether this will lead to an increase in use of it by the general population is a different question.
But even if they do, encryption isn't a failsafe privacy solution. Assuming that the code is sound, there are still some ways the kind of end-to-end encryption being newly promoted by some tech heavyweights could be undermined.
One is to simply crack encryption keys with brute force, which takes enormous computing resources. According to documents leaked by Edward Snowden, the NSA is seeking to develop colossal quantum machines that could break encryption. But this is still a way off, and Soltani says that it would probably be too difficult and time-consuming at the moment.
Another way to crack this kind of encryption is by circumventing the protection altogether, and getting to the communications or documents on the host computer before they've been encrypted.
This is most commonly done by installing malware on a target's computer or phone. Less sophisticated options for circumventing encryption include physically plugging a key-logger—a small device that records all keyboard strokes—into the computer.
bulk deployment of malware could also be possible
In response to these increasingly popular encryption services, Soltani suggests we may see an increase in attacks on devices. "We've seen this already with the FBI's recent attacks on Tor users and an earlier case involving sending malware to a mafia suspect, plus we're now aware of the NSA's huge catalog," he said.
At the moment, these sort of attacks are typically carried out against a specific target or targets, rather than in a broad sweep like metadata. And pieces of malware, Soltani added, "have the downside that they can sometimes be detected by the target (e.g. antivirus software)."
But he suggested that, in the future, broader spreads of encryption-bypassing malware could find their way onto devices. "Widespread (bulk) deployment of malware could also be possible, such as exploiting a backdoor in popular software such as the SSL Heartbleed vulnerability," he said.
One oft-forgotten NSA programme, codenamed TURBINE, is an automatic system that leaked documents suggest can implant malware into many computers, with relatively little human involvement.
In general, using malware to crack encryption can have broader implications: Soltani pointed out that most malware relies on finding vulnerabilities in software that is used by the target, but that the same software will be used by other people too.
"By not disclosing these vulnerabilities to the developers of the software, the government is essentially leaving the citizens they've sworn to protect vulnerable to attacks from other groups," Soltani said.
I have reservations in doing crypto in the browser as there are lots of places in which this process can fail
Last month, the Electronic Frontier Foundation launched a lawsuit against the NSA to find out more about what they do with zero-day flaws they discover, with policy analyst Eva Galperin arguing that, "Since these vulnerabilities potentially affect the security of users all over the world, the public has a strong interest in knowing how these agencies are weighing the risks and benefits of using zero days instead of disclosing them to vendors."
Both of these methods—using brute force or malware—apply to most types of end-to-end encryption. But when it comes to those that do their work in an internet browser, such as Google's offering, there are additional aspects to worry about.
"While I'm a big fan of anything that helps users to encrypt their communication and make bulk passive more difficult, I personally have reservations in doing crypto in the browser as there are lots of places in which this process can fail," Soltani said.
For example, your connection may not necessarily be over a secure connection such as HTTPS; or while checking your email, you could instead be directed to a fake site controlled by an attacker, allowing them to see whatever you type before it is encrypted.
Instead, groups such as the Freedom of the Press Foundation generally recommend that all encryption processes take place away from the browser, using a program such as Gpg4Win or GPGTools, or running your Gmail account through an email client such as Thunderbird.
But anything's probably better than nothing. Google's encryption app is still in an alpha stage, and Yahoo's won't be here until next year. Even if they don't take off and become widely used, the popularity of end-to-end encryption in general is rising. It wouldn't be surprising if attempts to crack it are too.