From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,9a441a9594e85d08 X-Google-Attributes: gid103376,public From: Markus Kuhn Subject: Re: Bignum modular types in Ada95 Date: 1998/01/30 Message-ID: <34D11876.5059EDD4@cl.cam.ac.uk>#1/1 X-Deja-AN: 320414913 Content-Transfer-Encoding: 7bit References: <34CE568C.55D7E23D@cl.cam.ac.uk> <34CF3E78.F816DB5@cl.cam.ac.uk> <34D082F9.ABEC0D3B@elca-matrix.ch> Content-Type: text/plain; charset=us-ascii Organization: Cambridge University, Computer Laboratory Mime-Version: 1.0 Newsgroups: comp.lang.ada Date: 1998-01-30T00:00:00+00:00 List-Id: 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: