From: db@Tadpole.COM (Doug Barnes)
Date: Tue, 13 Dec 94 15:06:02 PST
To: rishab@dxm.ernet.in
Subject: Re: Elliptic crypto is patented
In-Reply-To: <gate.imcBXc1w165w@dxm.ernet.in>
Message-ID: <9412132304.AA26604@tadpole.tadpole.com>
MIME-Version: 1.0
Content-Type: text/plain



> Incidentally Next Computer's Fast Elliptic Encryption, FEE, used
> elliptic curves, and is patented (by R E Crandell, USP# 5,159,632,27 October 
> 1992); also, elliptic crypto is probably covered by the DH/PKP patents.
> 

Is the FEE patent on some tweaking of it, or are they claiming 
anything using ECs for crypto? (Esp. DH and ElGamal analogue)?

PKP claims all public key, but: 

a) Vanilla El Gamal crypto is covered, tenuously at best, by their 
   Diffie-Hellman patent, which some consider to be contestable based 
   on publication more than a year before filing. The DH patent 
   expires in a few years as well.

b) EC-based El Gamal is ever farther from DH and vanilla El Gamal
   (since it uses different math). It is even less likely to be
   held to infringe.

PKP's overall claim to public key cryptography may also be
weakened by several different outcomes to the current round
of lawsuits.

One thing that is _not_ likely to be weakened is their claim on
RSA. Therefore, if you're not interested in supporting PKP's
attempt to make their strongest patent the centerpiece of 
various Internet standards, working towards EC encryption is a
Good Thing.