Does that NSA snooping thing have you swapping SIM cards and handsets on a daily basis? Heres some bad news: even that isnt enough to keep your cellular activities anonymous.
German researchers have found that every cellphone has a unique radio fingerprint. Its the result of subtle variations in the electronic components that are when manufacturing phones. Minute differences in things like resistance in parts like amplifiers and signal processors put a special stamp on the signal coming from every users handset.
The kicker: these radio signals can be monitored passively, meaning that the right people with the right equipment could identify phones without users ever knowing. Theres no need to scrape call metadata as the NSA does, just a sniffer with access to the airwaves.
The German team practiced its technique on 13 different phones in a laboratory setting and was able to identify a specific handset with 98% accuracy. The trick, of course, is scaling up to make the system usable in the urban jungle.
Dont put on your tin foil hat just yet, however. There are thousands of different phones broadcasting out in the real world, and its going to require exponentially more work to analyze their chatter using this new process.
Its also worth noting that only 2G phones were tested. The researchers noted that its theoretically possible to tag 3G and 4G phones, too, but they havent done it yet.
It might not be that far off, however. This is exactly the kind of thing that government agencies are likely to throw piles of money at and the British have already proven that monitoring fluctuations in the power grid can help solve crimes. Why not start monitoring the airwaves, too?
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