From: Stephan Somogyi <somogyi@digmedia.com>
Date: Sat, 3 Feb 1996 08:43:41 +0800
To: cypherpunks@toad.com
Subject: Looking for GSM A5 info
Message-ID: <v03004a09ad38400c7d12@[198.93.25.66]>
MIME-Version: 1.0
Content-Type: text/plain


I'm looking for information about the A5 encryption algorithm used in
GSM phones. Specifically:

- How does the algorithm work and is its encryption methodology similar
to any other well-known algorithms?

- Is A5's implementation mandatory to produce an world-wide
interoperable GSM device?

- What are the variants of A5 (there was some discussion of less secure
versions), how do they differ, and where are they used?

- Are there any known weaknesses in or attacks on A5-encrypted GSM
conversations?

- Are there notable instances where GSM deployment was delayed or
halted due to A5? (I remember hearing that such a delay happened in
Australia, but I don't recall details.)

Any related information, or pointers to related information,
appreciated greatly.

________________________________________________________________________
Stephan Somogyi                Mr Gyroscope                Digital Media