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Researchers decrypt data on mobile networks

Karsten Nohl says weak or no encryption on General Packet Radio Service networks makes them vulnerable to snooping.

Elinor Mills Former Staff Writer
Elinor Mills covers Internet security and privacy. She joined CNET News in 2005 after working as a foreign correspondent for Reuters in Portugal and writing for The Industry Standard, the IDG News Service and the Associated Press.
Elinor Mills
 
Crypto expert Karsten Nohl at Black Hat last year.
Crypto expert Karsten Nohl at DefCon last year. Seth Rosenblatt/CNET

Researcher Karsten Nohl is continuing his crusade to get mobile operators to improve the security of their networks by releasing software that can turn phones into mobile data snoops of GPRS (General Packet Radio Service) traffic.

Using a GPRS interceptor, someone could "read their neighbor's Facebook updates," he told CNET in a brief interview last week. He planned to release the software during a presentation today at the Chaos Communication Camp 2011 in Finowfurt, Germany, near Berlin.

Karsten of Security Research Labs in Berlin and a co-researcher Luca Melette were able to intercept and decrypt data sent over mobile networks using GPRS using a cheap Motorola that they modified and some free applications, according to The New York Times. They were able to read data sent on T-Mobile, O2 Germany, Vodafone, and E-Plus in Germany because of weak encryption used, and they found that Telecom Italia's TIM and Wind did not encrypt data at all, while Vodafone Italia used weak encryption, according to the report.

One reason operators don't use encryption is to be able to monitor traffic, filter viruses, and detect and suppress Skype, he told the newspaper.

Nohl has been pointing out weaknesses in mobile networks for years in the hopes that operators will step up their security efforts. In August 2009, he released the encryption algorithms used by mobile operators on GSM (Global System for Mobile Communications) networks. Last year, he released software that lets people test whether their calls on mobile phones can be eavesdropped on.