From: Phil Karn <karn@qualcomm.com>
Date: Wed, 17 Aug 94 15:07:48 PDT
To: cypherpunks@toad.com
Subject: Re: Complaints: Schlafly's complaint against RSA & PKP
In-Reply-To: <199408160305.UAA10417@zero.c2.org>
Message-ID: <199408172206.PAA13211@servo.qualcomm.com>
MIME-Version: 1.0
Content-Type: text/plain


These three statements are *most* interesting. The Diffie-Hellman
patent (4,200,770) itself references the Information Theory and AFIPS
papers and their publication dates. And as stated, the patent filing
date was Sept 6, 1977. Clearly anything in the AFIPS paper is fair
game since it appeared more than a year before filing. But for the IT
paper, I don't know whether the clock starts when the paper is
submitted or when it is actually published; that would make a
difference here. Anybody know?

--Phil
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36. The idea of public key cryptography and digital signatures is disclosed 
in a paper titled "Multiuser cryptographic techniques" by Whitfield Diffie 
and Martin E Hellman, National Computer Conference, vol. 45, 1976. The 
paper was presented at a public conference in mid-June 1976, and published 
as part of the conference proceedings shortly thereafter. This was more 
than one year before any patents were filed, and therefore in the public 
domain according to 35 USC 102(b). A copy of the paper is attached as 
Exhibit T. 
 
37. Another paper by Diffie and Hellman, "New Directions in Cryptography", 
IEEE Transactions on Information Theory, vol. IT-22, no. 6, Nov. 1976, was 
submitted on June 3, 1976. It discloses the public key distribution system 
of the DiffieHellman patent. A copy of the paper is attached as Exhibit U. 
 
38. A survey paper, "The First Ten Years of Public-Key Cryptography", was 
published by Diffie in Proceedings of the IEEE, vol. 76, no. 5, May 1988. A 
copy of the paper is attached as Exhibit V. It states on p. 563 that 
Exhibit U was publicly distributed in June 1976 and publicly disclosed at 
the National Computer Conference, also in June 1976. The Diffie-Hellman 
patent was filed on Sept. 6, 1977. This was more than one year later, and 
hence the patent is invalid and unenforceable according to 35 USC 102(b).