[80098] in Cypherpunks
RE: RSA, PGP IN LEGAL FLAP OVER ENCRYPTION TECHNOLOGY
daemon@ATHENA.MIT.EDU (Chris DiBona)
Thu May 15 01:58:59 1997
From: Chris DiBona <chrisd@loc201.tandem.com>
To: "cypherpunks@toad.com" <cypherpunks@toad.com>
Date: Wed, 14 May 1997 10:46:33 -0700
Reply-To: Chris DiBona <chrisd@loc201.tandem.com>
I don't pretend to be patent law knowledgeable, but I'll try to address =
this. While pure mathematics is unpatentable, the inventions based on it =
are not. Remembering you can't get patents on ideas, only inventions, I =
decided to go and check out the RSA patent and see why it has held up =
and been allowed renewal (no kidding. Think of all the trouble that =
could have been saved if renewal had been denied!)
This first thing I noticed is that not only is RSA patented, but so is =
Stego, under patent 5613004. The RSA patent is abstracted and here it =
is:=20
ABSTRACT: A cryptographic communications system and method. The system =
includes a
communications channel coupled to at least one terminal having an =
encoding device and to at
least one terminal having a decoding device. A message-to-be-transferred =
is enciphered to
ciphertext at the encoding terminal by first encoding the message as a =
number M in a
predetermined set, and then raising that number to a first predetermined =
power (associated with
the intended receiver) and finally computing the remainder, or residue, =
C, when the
exponentiated number is divided by the product of two predetermined =
prime numbers
(associated with the intended receiver). The residue C is the =
ciphertext. The ciphertext is
deciphered to the original message at the decoding terminal in a similar =
manner by raising the
ciphertext to a second predetermined power (associated with the intended =
receiver), and then
computing the residue, M', when the exponentiated ciphertext is divided =
by the product of the
two predetermined prime numbers associated with the intended receiver. =
The residue M'
corresponds to the original encoded message M.=20
For the actual details of the patent go to IBM's patent server: =
http://patent.womplex.ibm.com/details?patent_number=3D4405829
Notice how careful they were to title it a "System" and a "Method". It =
is that they are patenting. I think if someone had good enough lawyers, =
they could probably challenge this patent using prior art claims, but =
what the hell do I know. I'm thinking however that the Secure Telephone =
Units had a dual key system, and were introduced by AT&T long before the =
RSA patent was granted, but I'm not sure.=20
So indeed they are patenting the method of using the mathmatics. Which =
is thier invention, which is why (IMO) they were granted the patent. =20
I wish that they hadn't been able to get it renewed. It would have been =
nice to see how RSA would do competing thier software libraries against =
alternative competitors. Ah well, guess we'll have to wait another 17 =
years. Too bad.=20
Chris DiBona
-----Original Message-----
At 19:47 5/13/97 -0700, Kent Crispin wrote:
>On Tue, May 13, 1997 at 07:11:48PM -0800, Jim Bell wrote:
>> However, I've been waiting many years for some =
patent-law-knowledgeable
>> person to explain why mathematics, which was widely seen as being =
absolutely
>> unpatentable prior to the invention of public-key cryptography, =
suddenly
>> became patentable just in time for RSA, etc. =20
>>=20
>> Until I hear such an explanation, I _DO_ begrudge RSA and others that
"right."
>
>Wow! I agree with you!
Sit down until the feeling goes away.
Jim Bell
jimbell@pacifier.com
