This is an old revision of the document!


depends on:
interested: biiter
software license:
hardware license:
status: active

We aim to develop open-source GSM sniffer as presented on 29C3, including multichannel hardware sniffer “brmbora”, optimized keystream guesser “napalmex” (peaking at 99% success rate on insecure networks and with approx. 50% success rate even on secured networks), own A5/1 cracker “deka” and a fancy GUI. This is very WIP. Basically, we have a prototype of a $400 affordable 8-channel sniffer capable of monitoring several BTSs at once, we can crack recorded .dat files (send us some!) and currently we are working on an OpenCL A5/1 cracker. You can see the project architecture on the image below and download some source and CAD files.

Goals of the Project

  • improve our knowledge of GSM networks at all ;)
  • security research in GSM area

Status and Plan

The project is currently in the active stage.

  • [DONE] gsmbox - 8 osmocom compatible phones in one box with only USB as I/O.
  • [DONE] Run Kraken so we will be able to crack A5/1
  • Tune utilities for data capture
  • Tune Kraken (speedup, hardware, …)
  • GUI ?;)

Current tarbal containing various script and modifications is here:


This tarball is provided “as is”, poor coding quality guranteed, etc, etc.

outdated doc

GSM Shield

This shield is used in combination with FT4232HQMiniModule to attach 4 Motorola C series GSM phones to computer using 4 serial connections.

Material recomended:

  • FT4232HQMiniModule (sos.sk, farnell.com)
  • 4x 2.5mm audio-jack (ges.cz)
    • tip - TX, 2nd ring - RX, rest - GND
    • Standard 2.5 mm jacks are just too big ;(
  • FT4232H Shield - git repo
    • This shield is not necessary, but makes whole construction much more robust.

When assembled, it should look somehow like this:

GSM box

Basic idea is to put multiple (8) phones into 3,5“ HDD box. Only one usb cable as interface.


  • assign a separate page to it
  • design & make “holder” for phones inside the box (use rep-rap) ⇒ use smaller box.
  • remove filters from phones, so we can sniff upstream better



Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Noncommercial-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki