On Wed, 2010-06-02 at 06:55 +0200, Frank A. Stevenson wrote: > This line of reasoning would suggest that the first encrypted downlink > TDMA frame is completely known, regardless of the data content. >
I am afraid I have to correct myself at this point, it seems that SDCCH use block rectangular interleaving (57 bits), and not diagonal (6 bits). The confusion is due to some poorly labeled illustrations in a book that I am reading. Assuming the LAPDm frames are aligned to the 4 frames that are interleaved, this heightens the known plaintext requirements quite a bit. Studying raw intercepted frames would be a great help at this stage... f _______________________________________________ A51 mailing list [email protected] http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
