2010 might just be the year that the cellular phone calls become open to any hacker with the wherewithal to listen in. German hacker Karsten Nohl said this week that he has fulfilled his promise of cracking the GSM encryption code that protects phone calls from eavesdroppers while they traverse the airwaves. And while Nohl claims his publishing of the GSM codebook is purely academic, his project could significantly lower barriers for those with more malevolent intent.
IDG News’ Robert McMillian provides a good explanation of what exactly Nohl and his research team have done: cracking the 64-bit cipher called A5/A1 used to mask most GSM calls and SMS, Nohl has compiled a database of codes which can be used like a reverse phonebook to decrypt conversations and text messages. Using the codebook, antennas, some specialized software and about $30,000 worth of computing equipment, a hacker can crack a call in real-time, allowing him or her to listen in on live conversations. If that hacker is willing to wait a few minutes, a recorded call could be cracked in a few minutes using off-the-shelf computing equipment, according to Nohl.
The ability to listen in on cellular conversations isn’t new–it’s been available to law enforcement (and presumably criminals) for years–but the cost of the specialize equipment have made it prohibitive, according to PC World. Nohl’s codes make those capabilities available to just about anybody.