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GSM

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The aim of this project is to develop a GSM sniffer and tools for key recovery.

Project highlights: OpenCL A5/1 cracker and statistical keystream guesser capable of cracking the key in several seconds and 99% probability on an insecure network and in several minutes on a secure network with ~30% probability.

Project status:

Multichannel sniffer using FT4232 and 8 OsmocomBB phones controlled by Arduino. This does not seem to be an optimal choice today, a SDR and software demodulation would be much better. The sniffer was designed in 2011 before SDRs became widely available.
A5/1 cracker written in OpenCL. Works.
GSM stack with outdated and deficient documentation with lots of great features, but unmaintained and broken.
GSM stack fork with documentation and without lots of great features, but working.
Efficient plaintext guessing HOWTO

Missing parts:

UI that won't require excessive shell magic.
SDR-based sniffer capable of recording adjacent channels and decoding phonecalls after the key is cracked.
Statistical guesser using SI5/5ter/6 messages less stupidly than “we pipe them to the cracker and hope some will be solved”.

References

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