Re: [Cfrg] Hardware requirements for elliptic curves

Alyssa Rowan <akr@akr.io> Sat, 06 September 2014 14:52 UTC

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Date: Sat, 06 Sep 2014 15:52:54 +0100
From: Alyssa Rowan <akr@akr.io>
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Subject: Re: [Cfrg] Hardware requirements for elliptic curves
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On 05/09/2014 12:34, Johannes Merkle wrote:

> What I understood is that [hardware vendors] do not want to 
> specialize their hardware to minimize their investment while being
>  fully flexible (algorithm agile). […] Furthermore, I guess that
> new implementations can be built easier based on existing ones.

Quite. For decades, many vendors of cryptoprocessors have been basing
their implementations almost directly on existing ones with very few,
extremely conservative changes, presumably minimising their investment
by reusing as much as possible.

Respectfully, I do not think that conservative approach delivers
sufficient assurance where the integrity of the base is properly in
question: you don't add a conservatory to fix uncertain foundations.

While some existing hardware could indeed be adapted, whether abusing
the RSA multiplier where possible or (more likely, I feel) implementing
it entirely in firmware, I suggest those seeking these recommendations
for new elliptic curves, via an open process like this, should also have
plenty of concerns about crypto implementations presented as a closed
"black box" with an uncertain pedigree which has not also been designed,
audited, and certified as openly as possible from its inception. Rusty,
closed crypto hardware with new paintwork is, I feel, unlikely to meet
those needs.

I'm not aware of any cryptoprocessor vendor who has shipped any new
hardware like that, but I would heartily welcome and encourage it.

I gather a few efforts are under way from private teams, as has been
previously discussed.

- -- 
/akr
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