Etdot.com

Cellphone Encryption Code Is Divulged; By KEVIN J. O’BRIEN; Published: December 28, 2009

Excerpt:

BERLIN — A German computer engineer said Monday that he had deciphered and published the secret code used to encrypt most of the world’s digital mobile phone calls, saying it was his attempt to expose weaknesses in the security of global wireless systems.

The action by the encryption expert, Karsten Nohl, aimed to question the effectiveness of the 21-year-old G.S.M. algorithm, a code developed in 1988 and still used to protect the privacy of 80 percent of mobile calls worldwide. (The abbreviation stands for global system for mobile communication.)

Mr. Nohl said the algorithm’s code book was available on the Internet through services like BitTorrent, which some people use to download vast quantities of data like films and music. He declined to provide a Web link to the code book, for fear of the legal implications, but said its location had spread by word of mouth.

The G.S.M. algorithm, technically known as the A5/1 privacy algorithm, is a binary code — which is made exclusively of 0’s and 1’s — that has kept digital phone conversations private since the G.S.M. standard was adopted in 1988.

SOURCE: http://www.nytimes.com/2009/12/29/technology/29hack.html