From: Markus Kuhn <Markus.Kuhn@cl.cam.ac.uk>
Subject: Re: Bignum modular types in Ada95
Date: 1998/01/30
Date: 1998-01-30T00:00:00+00:00 [thread overview]
Message-ID: <34D11876.5059EDD4@cl.cam.ac.uk> (raw)
In-Reply-To: EnKEtu.KGp@world.std.com
Robert A Duff wrote:
> >- Are the numbers _really_ big ? In this case, you will implement
> >multiplication and division using Fourier transforms, which is overkill for
> >medium size bignums.
>
> I don't care. I'll be happy with an implementation that works.
Fair. Of course, compiler developers who strive for excellency would
be smart and would determine the 0..2^n over which FFT is faster
than simple multiplication and call an FFT routine for the types
where this is justified (say over 0..2**128 or so).
But I fully agree with you: Having it operational at all is
important first to ensure portability. Then you can worry about
efficiency.
If we have arbitrary length string operations, arbitrary
length integer operations shouldn't be that much additional
hazzle, and the popularity that arithmetic with huge numbers
has gained through the numerous asymmetric cryptoalgorithms
out there (RSA, Diffie-Hellman, ElGamal, DSS, all the new
elliptic curve stuff, etc.) surely justifies the investment.
Markus
--
Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK
email: mkuhn at acm.org, home page: <http://www.cl.cam.ac.uk/~mgk25/>
next prev parent reply other threads:[~1998-01-30 0:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-01-27 0:00 Bignum modular types in Ada95 Markus Kuhn
1998-01-28 0:00 ` Dmitriy Anisimkov
1998-01-28 0:00 ` Nick Roberts
1998-01-28 0:00 ` Nick Roberts
1998-02-01 0:00 ` Robert Dewar
1998-02-07 0:00 ` Nick Roberts
1998-02-09 0:00 ` Robert Dewar
1998-01-28 0:00 ` Larry Kilgallen
1998-01-28 0:00 ` Markus Kuhn
1998-01-28 0:00 ` Brian Rogoff
1998-01-29 0:00 ` Markus Kuhn
1998-01-30 0:00 ` Brian Rogoff
[not found] ` <EnIIvn.3zr@world.std.com>
1998-01-29 0:00 ` Markus Kuhn
1998-01-31 0:00 ` Nick Roberts
1998-01-29 0:00 ` Mats Weber
[not found] ` <EnKEtu.KGp@world.std.com>
1998-01-30 0:00 ` Mats Weber
1998-02-01 0:00 ` Robert Dewar
1998-02-01 0:00 ` Robert Dewar
1998-01-30 0:00 ` Markus Kuhn [this message]
1998-01-30 0:00 ` Mats Weber
1998-01-30 0:00 ` Markus Kuhn
1998-01-31 0:00 ` Nick Roberts
1998-02-01 0:00 ` Robert Dewar
1998-01-31 0:00 ` Nick Roberts
1998-02-01 0:00 ` Robert Dewar
1998-02-01 0:00 ` Robert Dewar
1998-02-01 0:00 ` Robert Dewar
1998-02-02 0:00 ` Tarjei T. Jensen
1998-02-02 0:00 ` Robert Dewar
1998-02-03 0:00 ` Tarjei T. Jensen
1998-02-04 0:00 ` Keith Thompson
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