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From: koontzd@phobos.lrmsc.loral.com (David Koontz )
Subject: Re: new encryption
Message-ID: <1993Apr22.200205.15384@wdl.loral.com>
Sender: news@wdl.loral.com
Organization: Loral Rolm Mil-Spec Computers
References: <1r4e9d$pdo@sol.TIS.COM> <1993Apr21.225435.6292@wam.umd.edu> <strnlghtC5wC3z.Erw@netcom.com>
Date: Thu, 22 Apr 1993 20:02:05 GMT
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>From: denning@guvax.acc.georgetown.edu
>                     THE CLIPPER CHIP: A TECHNICAL SUMMARY

>                               Dorothy Denning

>                           Revised, April 21, 1993

>The chips are programmed by Mykotronx, Inc., which calls them the
>"MYK-78."  The silicon is supplied by VLSI Technology Inc.


>All Clipper Chips are programmed inside a SCIF (Secure Compartmented
>Information Facility), which is essentially a vault.  The SCIF contains
>a laptop computer and equipment to program the chips.  About 300 chips
>are programmed during a single session.  The SCIF is located at
>Mykotronx.

>ACKNOWLEDGMENT AND DISTRIBUTION NOTICE.  This article is based on
>information provided by NSA, NIST, FBI, and Mykotronx.  Permission to
>distribute this document is granted.

So, who is Mykotronx, Inc.?  It would be nice to know that they were
not a front company used by an intelligence or other agency of the 
U.S. government.  Trusting the fox to guard the chickens, and all that.
Seems suspicious when the rest of the sources are foxes.

While we are at it, the chip design(s) should be examined and verified
against silicon to insure no trap doors or hidden protocols exist in silicon,
regardless of the security level of the encryption algorithm.  It would be a 
shame if some three letter agency had the ability to interrogate my chip, when
all I'd know is that someone rang, and when I attempted to go off hook the
line went dead.  Could be even worse if the chip were intended to connect
directly to a modem.

The design examination should be done to the gate level.  Does anyone have
a good idea how to tell if there is a piggyback design on silicon?  The model
would be extra logic sharing pins with the advertised function.  Tip offs
would be circuitry that would ignore incoming data if formats or sequence
is not right.  I can think of only two ways an output pin could be used,
and its possible that might be noticed, but could be edited from the netlist.
I think the silicon itself needs to be investigated.  Imagine a design
done in two layer metalization, yet finding a third layer under the
microscope.  

The government is asking for a lot of blind trust:  the encryption algorithm, 
operating protocols, the agency having physical control of the devices, the 
silicon implementation.  I'd feel like keeping one hand on my wallet.



