However, Simon Bransfield-Garth, chief executive of mobile encryption firm Cellcrypt, said that Mr Nohl’s work would make it far easier for criminals to intercept calls. “This will reduce the time to break a GSM call from weeks to hours,” he told the New York Times.
Most mobile phone calls worldwide are made using the GSM standard. GSM calls are protected by a 22-year-old encryption algorithm, known as A5/1. The algorithm, which is designed to prevent mobile phone calls from being intercepted by eavesdroppers, works by forcing mobile phones and bas stations to continually change frequencies. A typical phone conversation changes frequencies around 60 times.
The GSM Association has had a stronger algorithm, called A5/3, available since 2007 but few mobile network providers have made the upgrade.
