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Re: [Cfrg] Meeting notes

Derek Atkins <derek@ihtfp.com> Wed, 01 April 2015 20:24 UTC

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From: Derek Atkins <derek@ihtfp.com>
To: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
References: <CAHOTMVKUyNsA7ux4epk8LwR0w0Eh7dh0G3xTXB3O9m8jQPS3EQ@mail.gmail.com> <0C65868C-1725-4B32-A562-62C9DF36A956@gmail.com> <c65696d44c65b12478532bcb01fb2ef3.squirrel@mail2.ihtfp.org> <94D99ECB-98CA-4D25-897D-BA4BA8178409@gmail.com> <87y4mhtf5a.fsf@alice.fifthhorseman.net> <F7CF0AB9-4F3E-4FD4-B4D2-2F5172CB4BF2@gmail.com> <20150330104505.GA11195@LK-Perkele-VII>
Date: Wed, 01 Apr 2015 16:24:52 -0400
In-Reply-To: <20150330104505.GA11195@LK-Perkele-VII> (Ilari Liusvaara's message of "Mon, 30 Mar 2015 13:45:05 +0300")
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Subject: Re: [Cfrg] Meeting notes
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Ilari Liusvaara <ilari.liusvaara@elisanet.fi> writes:

> I haven't really looked, but on surface the algorithm doesn't look to
> be friendly for constant-time implementation. Matrix row or column
> swaps are involved?

No, it does not involve row or column swaps.

> So constant-time implementation would likely be a lot slower (it could
> still be much faster than ECC).

It's actually not slower; indeed, our current implementatons (both in
software and hardware) are constant time.

> Modern CPUs and OSes are pretty ridiculously vulernable to timing
> attacks. Even across VMs.
>
>
> Another advantage: It uses medium primes, which are much
> easier to work with than large primes (one can't use medium primes
> with ECC due to weak fields). For CPU work, 2^31-1 looks to be pretty
> convinient prime.

-derek
-- 
       Derek Atkins                 617-623-3745
       derek@ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant

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