William Knowles
Sat, 17 Feb 2001 11:54:13 -0800
Hello, I had this question asked by a subscriber of Infosec News http://www.c4i.org/isn.html After posting the near-FUD article on Bin Laden's use of stegography and I was unable to answer it, Could someone help me with this? Thanks in advance! William Knowles Moderator/ISN [EMAIL PROTECTED] *==============================================================* "Communications without intelligence is noise; Intelligence without communications is irrelevant." Gen Alfred. M. Gray, USMC ================================================================ C4I.org - Computer Security, & Intelligence - http://www.c4i.org *==============================================================* ---------- Forwarded message ---------- Newbie question: Can you tell by statistical or other fiddling with a file whether it has stuff embedded in it? I am thinking in terms of the frequency space analysis that coherent optical processors used to do--presumably brute force has superseded that sort of stuff, though. Consider writing the binary bit stream to the input plane. The frequency plane would show light output characteristic of specific pattterns in that stream. I wonder if the power spectrum in the frequency plane would show anything in particular besides the synchro or preamble and packet header bits in the traffic. Masks would allow useful screening so that extraneous patterns would be eliminated. This would require that the stego files had a characteristic synchro or discovery/start here pattern or some other typical pattern which could be widely dispersed and still discoverable by optical means. Seemds like stego would require some agreed on convention or marker as to where to look for hte goodies.