Re: [Cfrg] Chopping out curves

Watson Ladd <watsonbladd@gmail.com> Fri, 17 January 2014 19:23 UTC

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Date: Fri, 17 Jan 2014 11:23:30 -0800
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From: Watson Ladd <watsonbladd@gmail.com>
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Subject: Re: [Cfrg] Chopping out curves
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On Fri, Jan 17, 2014 at 11:17 AM, Manuel Pégourié-Gonnard
<mpg@elzevir.fr> wrote:
> On 17/01/2014 20:01, Watson Ladd wrote:
>> Okay. I'll follow the Ed25519 paper and call it te25519 and add the
>> paper as a reference.
>> Are rationals fine, or do people want me to write big numbers?
>
> I'm sorry, but I'd prefer big numbers (or best, both). Of course it's more work
> for you, but it's less for the readers. And since the document will hopefully be
> read more often than it is written... :)

Blegh. This is going to be one ugly looking equation. 4/5 and
-121665/121666 I can memorize.
Can't do the same with giant numbers. Okay, time to fire up PARI and
make the changes.

>
> Unrelated, but Alyssa wrote:
>>> • But if we call it 'Ed25519', people might confuse it with the whole
>>>   Ed25519 signature scheme.
>>>
> With all the respect I have for the great work done by Bernstein on this, I find
> it unfortunate that the same name is used for a curve, a particular protocol
> using this curve (and often even "the" implementation), causing some confusion.

I'm not sure this is correct. Bernstein's implementation today is the
donna implementation,
and tweetnacl has tweetnacl implementation of cuve25519. It's no worse
than BLAS, where
ATLAS, gotoBLAS, netlib BLAS, and Intel all provide implementations of BLAS.

> I'll be really glad if the I{R,E}TF encourages more distinct names for curves
> and protocols (and of course, many distinct interoperable implementations as usual).

ECDH on curve XXXX seems to be what people do when disambiguation is required.
>
> Manuel.
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