- Nicolas Paglieri
Passionate about Technology

Security - A5/2 Hack Tool

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A52 Hack Tool (A52HackTool)

 Nicolas Paglieri 
Olivier Benjamin

 Copyright © 2011 
 All rights reserved. 
License: GNU GPL v3

Current version: 1.3.0
Release date: December 1, 2011

It's an open secret that the privacy in GSM (Global System for Mobile communication, the standard used in 80% of the world's mobile phones) is compromised. The A5 set of ciphers it uses has been proven incapable of preventing data from being decrypted. The architecture of the standard makes it particularily vulnerable to man-in-the-middle attacks, and since all algorithms share a common key, the system is as weak as its weakest algorithm: A5/2.

The aim of this project, initiated in May 2011 and co-developed with Olivier Benjamin, was to design a concrete and turnkey implementation of a tool simulating an instant ciphertext-only attack on the A5/2 cipher, enventually allowing full GSM communication decryption. Our tool sucessfully cracks the cipher in a few seconds on a personal computer.

Project Timeline

01/12/2011 ♦ Code release (1.3.0)

24/06/2011 ♦ Code release (1.2.0)

08/06/2011 ♦ Code release (1.0.5)

08/06/2011 ♦ Article publication

17/05/2011 ♦ Project initiation

Resources and Documentation

Global Encoding Matrix for all Steps (Fire Code, Convolution and Interleaving)


Online Documentation of the Source Code

->A52HackTool Doxygen Documentation