Re: [Cfrg] Safecurves draft

Paul Lambert <> Thu, 09 January 2014 19:56 UTC

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From: Paul Lambert <>
To: Jon Callas <>, "" <>
Date: Thu, 09 Jan 2014 11:56:12 -0800
Thread-Topic: [Cfrg] Safecurves draft
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Subject: Re: [Cfrg] Safecurves draft
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+1 on a different name Š

Other comments:

1) Curve definitions really badly need clear parameterization.  Cutting
and pasting the referenced web site does provide all the right numbers,
but no context to implement. For the parameterization Š the curve math is
different so merging old and new in some fashion might make for
interesting comparison of the differences.

2) Is there any provenance on the generator selection for the curves?  I
hear critical comments on the NIST seeds, if we add new curves, should we
also document the process used for the selection of the Œarbitrary¹ values?

3) test vectors ..


On 1/9/14, 10:43 AM, "Jon Callas" <> wrote:

>Hash: SHA1
>I concur that we shouldn't call it "safecurves" or anything like that. I
>think that definitely this needs to heed Paul Hoffman's advice on names
>coming back to bite us.
>All crypto parameter sets have a lifespan where they're new and shiny,
>older and trusted, then kinda dodgy but accepted, and then outmoded or
>insecure. Each phase might be there for years or perhaps minutes. I've
>seen things go the entire lifecycle in an hour. We don't want the
>premature aging of one to tarnish the whole thing. Think about what you'd
>say when the Buzzfeed reporter calls you up for comment or background on
>their article "Ten Shocking Reasons Why SafeCurves are The Spawn of
>Satan" after a Eurocrypt paper has a new banana attack that shows a curve
>has ten fewer bits of security with 2^300 memory.
>I also think there should be a quick set of names where we specify what's
>a Montgomery and what's Edwards. This is already needed and the reason
>why there's 25519 and Ed25519 in current parlance. If we *don't* do it
>here, then someone else will. It's too useful not to have it.
>You can have a table with common names and extended names and have the
>extended names have something simple like a suffix of M or E. It's easy
>to fit 25519 and Ed25519 into this as well.
>	Jon
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