From: "Mark W. Eichin" <eichin@cygnus.com>
Date: Tue, 17 Nov 92 16:58:34 PST
To: hh@soda.berkeley.edu
Subject: re: Rander box and other stuff
In-Reply-To: <9211180036.AA19273@soda.berkeley.edu>
Message-ID: <9211180058.AA15692@tweedledumber.cygnus.com>
MIME-Version: 1.0
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>> Also you would probably need a permit to own thermite.
	I don't think there's a problem with owning it or making it --
only (perhaps) selling it and transporting it; thermite is not
strictly an explosive.
	You may wish to consider alternate ways of destroying the
data, especially if you wish to ever transport the device on a
commercial airline; if you've only got one RAM device that has
critical data in it, then simply arrange for the battery backup
circuit to have a "high current mode", perhaps feeding more of the
pins -- a "light emitting RAM" should be just as blank as one burned
through by thermite.

>> cryptosystem:  analog input and output, for use as a phone line scambler.
>> Such a system could be manufactured for not too much money, I think.  It
	Let's see -- an ISDN-quality (quality? I use the term loosely)
codec should be under $50 single quantity, the data rate isn't very
high so you don't need much of a CPU (6811 might even be enough, and
they're easy to interface to things -- lots of on-chip I/O). You'd
need a modem-style encoder for the output (running digital from
box-to-box -- "analog" scrambling (Time or Frequency domain) is way
too easy to break) so maybe another $50 DSP chip... after all, you
don't need to support 30 different baud rates, just one data rate with
perhaps a low-line-quality backoff. The connectors and the box are
probably the major recurring cost (the chip prices will go way down in
quantity.) Am I missing anything? The technology level of the Newton
seems to be a bit of overkill (unless you actually want that kind of
user interface.)

					_Mark_ <eichin@cygnus.com>
					<eichin@athena.mit.edu>
: note that this is an unsigned message.