From: William Oldacre <76114.2307@CompuServe.COM>
Date: Mon, 3 May 93 10:02:41 PDT
To: <cypherpunks@toad.com>
Subject: RSA patent!
Message-ID: <930503164336_76114.2307_BHA68-1@CompuServe.COM>
MIME-Version: 1.0
Content-Type: text/plain


To: >Internet:cypherpunks@toad.com

Enclosed is the essential text of the "RSA" patent.  Now it's time to 
go to work.

1)  (Interference) Is there anything in history wherein someone 
created a cypher consisting of two parts which could only be broken 
when they were combined mathematically?  Or how about a wax seal 
created by impressing two images, one after the other-----verifying 
authenticity?

2)  (Interference) Stripped of it's turgid language, does the basic 
equation fit any other ordinary operation such as factoring some type 
of equation.  Is there some routine mathematical operation in number 
theory which resembles it?

3)  (Invalidity) is there any part of the description language that 
could be interpreted two different ways?

4)  (Misuse)  a) Were any federal funds used in this project?  
Somebody at MIT needs to dig into the public documents there.  b) If 
so, was the government irresponsible in licensing something so useful 
to the public to a company (in which they are a partner) which makes 
it's use by the public difficult?  Can any evidence be found that this 
was deliberate?

5)  (Misuse)  Does RSA telling Phil Zimmermann that they will "never" 
license PGP to use RSA constitute monopolistic abuse?

6)  (Misuse)  The underlying purpose of the patent system was to 
encourage the creative genius for the benefit of the public.  Has the 
public benefited in this case?

7)  Keep thinking, and volunteer to take on some aspect of this and 
research it.  Most research is not done by attorneys but, rather, by 
assitants who simply assemble the case histories for them to work 
from.  By doing this work ourselves, any attorney or company wishing 
to challenge this patent in court is halfway there.


   1475889   2329848  E/ CRYPTOGRAPHIC COMMUNICATIONS SYSTEM AND METHOD
   --------------------------------------------------------------------

Inventors: Adleman Leonard M (US); Rivest Ronald L (US); Shamir Adi (US)
Assigned to: Massachusetts Institute of Technology  
Code: 52912
Patent Number: 4405829
Application Number: US 860586
Application Date: 12/14/77
Issue Date: 9/20/83
Patent Type: Utility
Citations: Cited by 29 later patents

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 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.

Exemplary Claim:
----------------
A communications system for transferring a message signal Mi comprising k 
terminals, wherein each terminal is characterized by an encoding key Ei (ei, 
ni) and decoding key Di (ei, ni), where i 1,2, . . . ,k, and wherein Mi 
corresponds to a number representative of a message signal to be transmitted 
from the ith terminal, ni is a composite number of the form ni pi X qi Pi and 
qi are prime numbers, ei is relatively prime to 1 cm(pi-1,qi-1), di is a 
multiplicative inverse of ei(mod(1 cm((pi-1),(qi-1)))) wherein a first 
terminal includes means for encoding a digital message word signal MA for 
transmission from said first terminal (i A) to a second terminal (i B), said 
first terminal including: means for transforming said message word signal MA 
to one or more message block word signals MA', each block word signal MA being 
a number representative of a portion of said message word signal MA in the 
range 0 < OR = MA < OR = nB-1, means for transforming each of said message 
block word signals MA'' to a ciphertext word signal CA, CA corresponding to a 
number representative of an encoded form of said message block word signal 
MA'', whereby: CA identical MA''eB(mod nB).