From: "Brian J. Harvey" <bjh@northshore.ecosoft.com>
Date: Wed, 30 Mar 94 19:04:17 PST
To: cypherpunks@toad.com
Subject: The dumbest question...
Message-ID: <Pine.3.89.9403302137.A6140-0100000@northshore.ecosoft.com>
MIME-Version: 1.0
Content-Type: text/plain



... is the one you don't ask. So here I go...


#1

Isn't "part of the deal" of patent granting a requirement that the 
details of the thing being patented be revealed. If so, why isn't IBM 
required to reveal the details of s-box design? After all, they hold the 
patent on DES.

#2

Skipjack has a 80 bit key which is proposed to be "escrowed" in two parts.
Now considering that the likeliest attack on DES is a brute force key 
search of 2^55 keys, isn't it true that a compromise of one half of a 
"Clipper key" would allow a brute force attack to "discover the remaining 
40 bits. If 2^55 is possible, then 2^40 is even easier, no? 


Brian