Topic: Open-Source Effort to Hack GSM

[sam]

Each GSM phone has its own secret key, which is known by the network. Every time a call is initiated, a new session key for that particular call is derived from the secret key and used to encrypt the call. Nohl aims to crack the session key.

"The engineer has designed an open-source software program that participants in his A5/1 cracking project can install on their PCs and use to share the task of computing the lookup tables that make up the cryptography system. The final codebook with the computed tables will be shared across a peer-to-peer network. Therefore, no one computer contains all the files, making it difficult, if not impossible, to remove the cracking tool entirely from the Internet

http://spectrum.ieee.org/telecom/wireless/open-source-effort-to-hack-gsm