From: Jim Thompson <jim@smallworks.com>
Date: Wed, 24 Apr 1996 20:21:24 -0700 (PDT)
To: stewarts@ix.netcom.com
Subject: Re: RISKS: Compuserve "secure" login
In-Reply-To: <199604242010.NAA02828@cygnus.com>
Message-ID: <9604250317.AA20026@butthead.SmallWorks.COM>
MIME-Version: 1.0
Content-Type: text/plain


 
> A couple years ago I found an obvious application of Diffie-Hellman which
> avoids this problem; unfortunately it turned out to be patented by someone
> from Siemens (first as a German patent and then a US patent, so it's
> definitely too much trouble to try to overturn the patent...)
> The basic approach is to use a commutative hash function, which lets
> both sides calculate HA(B) == HB(A) ; modular exponentiation worked fine.

Any chance that you're willing to discuss this further?

-- 
Jim Thompson / Smallworks, Inc. / jim@smallworks.com  
      512 338 0619 phone / 512 338 0625 fax
The Internet is Microsoft's Vietnam...