[623] in cryptography@c2.net mail archive
Re: RPK?
daemon@ATHENA.MIT.EDU (Colin Plumb)
Tue Apr 22 10:45:15 1997
Date: Mon, 21 Apr 97 23:02:02 MDT
From: colin@nyx.net (Colin Plumb)
To: gary@systemics.com
Cc: cryptography@c2.net
> Your comment that "it is no faster than any other implementation of such
> an idea" sort of implies that you are saying all Diffie-Hellman
> algorithms are as fast as each other? If this is indeed what you are
> implying, then how do you explain the performance gains of DH over
> elliptic curves, or are you saying this isn't any improvement?
What I meant is that, as far as I have seen, GF(p) and GF(2^k) are
roughly similar in speed for comparable sizes. Maybe one order of
magnitude, depending on implementation quality.
Elliptic curves can make a significant difference, with careful
attention to implementation. What I meant was "it isn't substantially
faster than any other implementation of GF(2^k), which isn't
substantially faster than GF(p)".
> It's been a while since I read the RPK documentation, but I recall
> that it made no secret of the fact that this was Diffie Hellman. I
> did not come away with the impression they were claiming their algorithm
> was anything but Diffie-Hellamn.
There was no deliberate obfuscation, so it's perfectly clear to
someone with technical knowledge, but some of the marketing blurbs
were, IMHO, less than clear. In particular, all the documentation
I saw was at pains to distinguish RPK's "unified" system from
standard hybrid cryptosystems. I don't think there *is* a
difference.
> Er, not to put an even finer point on it, that's total nonsense.
> Diffie Hellman is quite capable of being used for Signatures,
> including blinded signatures.
Um... huh? I'll readily believe that there are discrete logarithm
blinded signature schemes (I just haven't read about them), and I am
guilty of saying "Diffie-Hellman" when I mean the braoder class of
discrete logarithm schemes, but I honestly think I would have heard of
such a thing as a _Diffie-Hellman_ signature sceheme if it existed.
Can you enlighten me?
--
-Colin
