A5/1 Decryption

h3. Overview

This open source software allows the 'cracking' of A5/1 keys used to encrypt GSM 2G calls and SMS.

The cracking utility Kraken, developed by Frank A. Stevenson, is written in C++/python and runs on AMD GPUs or CPUs.

Kraken leverages rainbow tables that were computed as a community effort.

h3. Mailing list

A public mailing list for announcements and discussion can be found "here":http://lists.srlabs.de/cgi-bin/mailman/listinfo/a51 .

You may also file bugs and support requests through the "issue tracker":http://opensource.srlabs.de/projects/a51-decrypt/issues/new if they are of little relevance to the majority of the mailing list subscribers.

h3. Code

The (read only) Kraken git can be fetched with 

<pre>

git clone git://git.srlabs.de/kraken

</pre>

h3. Rainbow tables

"Decryption is achieved with rainbow tables":https://srlabs.de/bites/decrypting-gsm/ , which can be downloaded:

1. Through "BitTorrent":https://opensource.srlabs.de/projects/a51-decrypt/files

2. From "Google Drive":https://goo.gl/Bsa97p (provided by community member Farid Nasiri - many thanks! Unverified.)

h3. Related projects

The A5/1 decryption was originally meant to be used with "Airprobe":http://airprobe.org), which allows interfacing with the radio waves with

the help of gnuradio.

Airprobe has, for most users, since been replaced by the cheaper "Osmocom phones":http://bb.osmocom.org

h3. Further reading

[[A51|Cryptoanalysis in greater detail]]