From: Matt Blaze <mab@crypto.com>
Date: Thu, 14 Jul 94 05:08:20 PDT
To: norm@netcom.com (Norman Hardy)
Subject: Re: Idle question...
In-Reply-To: <199407140729.AAA13105@netcom.netcom.com>
Message-ID: <199407141208.IAA09141@crypto.com>
MIME-Version: 1.0
Content-Type: text/plain



>At 09:12 1994/07/13 +1000, Ian Farquhar wrote:
>... Quoting someone else
>>
>>BTW, the algorithm leaked, it was not reverse engineered.  I do not expect
>>SKIPJACK to leak, as it's distribution would be VERY limited, even within
>>the NSA and chip houses.  Even A5 was reputed to be known to only 2 or 3
>>people within Motorola.
>...
>How many have access to the masks?
>
>

Assuming you're asking about the masks for the chips that implement
Skipjack (Clipper and Capstone), probably lots of people.  The
masks themeselves aren't classified (but are covered by standard
trade secret law).  But the masks alone won't help much.  According
to NSA, "part of the algorithm", probably including the configuration
tables for the S-boxes, is burned in to the chips in the secure
vault during the classified escrow programming session.  See my
February comp.risks post, "Notes on Key Escrow Meeting with NSA",
for more details.  (I think it's available somewhere in the
ftp.eff.org archive.)

If you're asking about A5 then I have no idea.

-matt