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- Path: sparky!uunet!zaphod.mps.ohio-state.edu!caen!spool.mu.edu!agate!messier.berkeley.edu!jbuck
- From: jbuck@messier.berkeley.edu (Joe Buck)
- Newsgroups: sci.crypt
- Subject: Re: PKP/RSA comments on PGP legality
- Date: 17 Dec 1992 22:46:47 GMT
- Organization: U. C. Berkeley
- Lines: 54
- Message-ID: <1gr00nINNi18@agate.berkeley.edu>
- References: <CKD.92Dec16145954@loiosh.eff.org> <scs.724599694@hela.iti.org> <1992Dec17.220115.2371@netcom.com>
- NNTP-Posting-Host: messier.berkeley.edu
-
- I cannot post to alt.security.pgp since we do not get it; others are
- welcome to forward this.
-
- In article <1992Dec17.220115.2371@netcom.com> strnlght@netcom.com (David Sternlight) writes:
- >Just a small factual correction for Steve Simmons. My understanding
- >is that some PKP patents expire in 1997 and others in about 2000.
-
- Correct. Here's the list of PKP patents, from an archive maintained by
- the League for Programming Freedom:
-
- 4,200,770
- Cryptographic Apparatus and Method
- filed 9/6/77
- granted 4/29/80
- inventors Hellman, Diffie, Merkle
- assignee Stanford University
- Exponential, and all other forms of, secret key exchange.
- This is the "Diffie-Hellman" patent.
- Public Key partners has exclusive sublicensing rights.
-
- 4,218,582
- Public Key Cryptographic Apparatus and Method
- filed 10/6/77
- granted 8/19/80
- inventors Hellman, Merkle
- assignee The Board of Trustees of the Leland Stanford Junior University
- Knapsack, and all other forms of, public key cryptography.
- This is the "Hellman-Merkle" patent.
- Public Key partners has exclusive sublicensing rights.
-
- 4,405,829
- Cryptographic Communications System and Method
- filed 12/14/77
- granted 9/20/83
- inventors Ronald Rivest, Shamir, Adleman
- assignee Massachusetts Institute of Technology
- The RSA public key cryptosystem, and any communication system that evaluates
- a polynomial modulo a prime number.
- This is the "RSA" patent.
- Public Key partners has exclusive sublicensing rights.
-
- 4,424,414
- Exponential Cryptographic Apparatus and Method
- filed 5/1/78
- granted 1/3/84
- inventors Hellman, Pohlig
- assignee Board of Trustees of the Leland Stanford Junior University
- A conventional cryptosystem that performs modular exponentiation. Not as
- important as the other 3 cryptography patents (Diffie-Hellman,
- Hellman-Merkle, and RSA).
- This is the "Hellman-Pohlig" patent.
- Public Key partners has exclusive sublicensing rights.
- --
- Joe Buck jbuck@ohm.berkeley.edu
-