Karsten Nohl, a German network security and cryptography expert, announced the discovery of a relatively simple technique of intercepting and decrypting data transmitted over the GPRS protocol.
His team also discovered that many mobile carriers use a low-security variant of GPRS, while some of them disable GPRS traffic encryption altogether.
There can be two reasons behind such ignorant attitude of mobile carriers to the security of their clients’ data:
- An attempt to save on equipment required for proper data protection.
- Deliberate disablement of data encryption for retaining access to clients’ data.
Karsten Nohl claims that his discovery is far from being theoretical: his team was able to capture and decrypt data in T-Mobile, O2 Germany, Vodafone and E-Plus networks. What made matters worse was that they did not have to use cumbersome equipment (they used a reflashed Motorola C-123 phone) or expensive software (they only used publicly available freeware). Even in this case, they managed to capture data in the radius of 5 km.
The details of this technique have not been published yet to avoid damage to the clients of cell phone companies. The research group believes that it’s high time that mobile operators did their homework and configured their GPRS gateways and checked all cryptographic systems, as the methodology they followed will be made public shortly.
However, Russian operators were quick to react: according to “The Big Three” (Beeline, Megafon, MTS), they don’t see how this could jeopardize their clients’ security and suggest using better-protected technologies, such as 3G.