Did Snowden, who filed an NSA whistleblower, hide his cell phone in the fridge?
The New York Times reported that when Edward Snowden was in Hong Kong, when a group of lawyers went to see him, he would hide his cell phone in the fridge to prevent any wiretapping attempts. It seems that he asked for it.
Why is it a refrigerator? Does it have any effect on temperature? No, no. The refrigerator can be turned off. The gimmick is on the thick metal wall of the refrigerator. This makes it a perfect wiretapping prevention device.
"There are two purposes," explains Adam Harvey, a designer specializing in anti-surveillance products. "To block the radio signals used to send audio data, and to block audio altogether." According to the expert, some models of refrigerators can effectively perform both of these tasks.
In fact, from a data transmission point of view, metals can create some sort of electromagnetic barrier. It's known as the "Faraday cage." The inside is a space where electromagnetic waves cannot enter, and as a result, information cannot be transmitted.
In Harvey's opinion, there is another household item that could work in the same way. It's a stainless steel cocktail shaker. "This is the perfect Faraday cage, blocking any radio signal." Naturally, I had to make a cocktail and pour it.
Joke aside, Harvey actually tested it on a shaker (the results seemed to be good), developed an eavesdropping prevention case for smartphones, and named it OFF-Pocket.
If you're thinking of turning off your device and removing the battery, this is off the mark. Some devices are not easy to remove the battery. And do you know that your smartphone is really off?
"Most of today's electronic devices (not just mobile phones) are half-powered and half-off. Even if some of the circuits are paused, some are still active. We continue, "explains Seth Schoen of the Electronic Frontier Foundation. "Electric devices in such intermediate modes will automatically turn on when some conditions are met, such as pressing a button or receiving data via the Internet (a mechanism known as Wake-on-LAN). You can put it in. "
Removing the battery may just mislead you into thinking that the power is off. That's because there may be additional power sources inside the device that can't be removed. Harvey explains further. "Some mobile phones utilize an auxiliary battery for memory management. It's not clear if this battery can be used for surveillance and tracking systems like Carrier IQ. ".
Is it a groundless story? Judgment is difficult. Sure, refrigerator doors block sound well, but some argue that sound waves could be used to send data from inside the Faraday cage as well.
We sought views from two experts. Matteo Jacarone and Domenico Marsella of the Institute for Communication, Information and Cognitive Technology at Scuola Superiore Sant'Anna in Pisa.