Recently, the New York Times reported on how NSA whistleblower Edward Snowden was extremely cautious about arranging his trip from Hong Kong to Russia (emphasis mine):
“It was a secretive operation. Mr. Snowden wore a cap and sunglasses, and insisted the lawyers present hide their cellphones in the refrigerator of the residence where he was staying to prevent eavesdropping. Then, a two-hour discussion ensued during which Mr. Snowden expressed his deep concern upon learning he could be imprisoned for years without access to a computer while a legal battle over his asylum or extradition took place.
Wait a minute. Why were the cellphones being cooled? Snowden’s assumption was likely that the refrigerator would serve as a Faraday cage. As I explained last year when discussing the functionality of tin foil helmets, a Faraday cage is a structure made from conducting material that shields its contents from external electromagnetic radiation and electrostatic charges by rerouting them around its outer surface. While Faraday cages can take the form of literal enclosures, they come in many different shapes, and most of us have encountered them in some form. MRI scan rooms and the shielding on USB cables, for instance, are examples of Faraday cages. Inside such a cage, the signals sent to and from the lawyers’ phones would be blocked, making it impossible to surveil the meeting.
In theory, a solid metal refrigerator could work as a Faraday cage. However, in practice, some refrigerators fail to completely block a cell phone’s connection to the outside world. Make magazine writer Michael Colombo tested this with his own fridge and managed to make a call to a phone placed inside it. He had more success with a metal cocktail shaker.
I tested my fridge too and got the same result. Calls and data came through without issue. Since I have a glass cocktail shaker, it’s not a viable option for me if I need to stay undetected. I began to wonder if there was a more practical kitchen Faraday cage available for people like me, or for those who don’t even own a cocktail shaker.
I spent some time browsing survivalist message boards (not a habit I recommend) and discovered that many doomsday preppers plan on using their microwave to protect electronics in the event of a government, alien, or New World Order electromagnetic pulse. This seems reasonable, as unlike a fridge, a microwave oven is designed to block electromagnetic radiation, keeping it contained within. If the radiation can’t escape, it shouldn’t be able to enter either.
As expected, when I placed my phone inside my old GE microwave, calls and data signals were completely blocked. I could see the phone inside, but it didn’t ring, and there were no notifications. When I removed it, there were no missed calls either. So, if you need to keep your phone secure from prying eyes and ears, your best bet is to pop it in the microwave or a (metal) cocktail shaker. Just don’t forget about it when reheating food or mixing up a drink.
Buzz
