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Re: [Cfrg] What constitutes a curve with a 256-bit security level?

Tony Arcieri <bascule@gmail.com> Wed, 18 February 2015 22:39 UTC

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From: Tony Arcieri <bascule@gmail.com>
Date: Wed, 18 Feb 2015 14:38:45 -0800
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To: Michael Hamburg <mike@shiftleft.org>
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Subject: Re: [Cfrg] What constitutes a curve with a 256-bit security level?
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On Wed, Feb 18, 2015 at 2:14 PM, Michael Hamburg <mike@shiftleft.org> wrote:

> It may be that you’re thinking SHA512-and-truncate won’t be uniform enough
> mod the order of Ridinghood.  But in fact it will, because the order of
> Ridinghood is 2^480 - O(2^240), and so the deviation from uniformity will
> be O(2^-(240+32)).  The same would not be true for a prime with a large
> coefficient like NIST P-256.
>

Okay, my mistake, but that is an issue for E-521, right?

-- 
Tony Arcieri

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