Edward Snowden, the former National Security Agency contractor turned whistleblower, presented a plan for a smartphone add-on that could help people evade government surveillance on Thursday.
Snowden teamed up with the hacker Andrew “bunnie” Huang to design the device, a piece of hardware that would affix to an Apple (aapl) iPhone and that would alert a person whenever that handset leaked location data. Based in Russia, he introduced the proposal courtesy of livestream video at a day-long conference on “Forbidden Research” at the Massachusetts Institute of Technology’s Media Lab.
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Snowden said that journalists, especially ones reporting in high-risk situations in foreign countries, are not able to trust that their phones will keep their whereabouts quiet, even when set to “airplane mode.” Intelligence agencies and hackers can compromise the handsets with malicious software to make them appear safe, when really the devices are tattling.
Snowden cited the example of Marie Colvin, a reporter for The Sunday Times, who was killed by the Syrian Army in an artillery strike in 2012. (Colvin’s family is suing the country’s administration, alleging that it targeted her after intercepting her broadcasts.)
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Smartphones come equipped with a number of radio transmitters and receivers, for GPS, SIM card, Wi-Fi, and Bluetooth functionality, as Snowden and Huang lay out in a co-authored paper describing the module’s specs. The pair’s device is designed to detect signals from these features and notify a person on a separate display when they’re active.
Huang, Snowden’s partner, gained notoriety by becoming the authority on hacking Microsoft’s (msft) Xbox video game console. He also recently filed a lawsuit against the United States government for its digital copyright laws, which he says inhibit security research.
At the moment, the anti-spy device is just an experiment. “The next step is refining the system for field deployment,” the two wrote in their paper. “Over the coming year, we hope to prototype and verify the introspection engine’s abilities.”