Message-Id: <9306181940(_dot_)AA18250(_at_)transfer(_dot_)stratus(_dot_)com>
Subject: Re: Triple DES on PEM WG Agenda
Date: Fri, 18 Jun 93 15:40:43 -0400
From: Steve Kent <kent(_at_)BBN(_dot_)COM>
I agree with your characterization of the problem. I also
believ it is a bad idea to adopt multiple versions of a triple-DES
mode. So, if this topic is discussed in Amsterdam and if there is
agreement to add a triple DES option, the result shuld be selection of
a single defintion of how PEM could make use of triple-DES, not the
creation of a menu of several options.
Steve,
if this topic comes up in Amsterdam, then, I hope that the
performance implications of CBC choice are weighed carefully and that the
single choice is of 3 feedback paths (probably with 3 IVs, although one
could use a single IV three times, I suppose). The single feedback path
choice is such a strong performance loser that I don't believe it would be
responsible to choose it as a single definition.
- Carl
[P.S. I'm only an amateur cryptologist but I have been a professional
performance in my recent past and this is a *major* issue to me. I have not
added much to the pem-dev discussion over the years but this is one place
where I believe I have something of value to offer.]