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From: Jay Ashworth <jra () baylink com>
Date: Sat, 15 Jun 2013 14:11:00 -0400 (EDT)
----- Original Message -----
From: "Scott Helms" <khelms () zcorum com>
Is it possible? Yes, but it's not feasible because the data rate would be
too low. That's what I'm trying to get across. There are lots things that
can be done but many of those are not useful.
I could encode communications in fireworks displays, but that's not
effective for any sort of communication system.
At this point, of course, we hearken back to the Multics system, which
needed -- in order to get the B1(?) common criteria security rating that it
had -- to prevent Covert Channel communication between processes of different
security levels *by means as low-bandwidth as sending morse code by
modulating the system load*.
So I don't think "there's too little bandwidth" is a good enough argument,
But there's a much more important issue here:
In some cases, like the Verizon Wireless 4G puck I mentioned earlier,
manufactured by ZTE, *you can't see the back side of the device*. There's
nearly no practical way for a subscriber to know what's coming out of the
4G side of that radio, so it could be doing anything it likes.
Verizon Wireless proper could know, but they have no particular reason to look
and, some might argue, lots of reasons not to want to know.
Jay R. Ashworth Baylink jra () baylink com
Designer The Things I Think RFC 2100
Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII
St Petersburg FL USA #natog +1 727 647 1274