Re: [TLS] Twist security for brainpoolp256r1

[Alyssa Rowan <[e-mail]>]

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On 14 November 2014 22:46:13 GMT+00:00, Oleg Gryb <[e-mail]>
wrote:

> I had to change 'speed.c' in openssl to add barinpoolp256r1 (by 
> default it simply not there). The difference for both ecdsa 
> (signature) and ecdh (diffie-hellman-merkle key exchange) is less 
> than 5%, so P-256 'optimization' in openssl is definitely
> overrated.

No, you just don't have the optimisation turned on: that's using the
old unoptimised generic prime routine.

If you're on 1.0.1, Configure/make depend/make it with flag
enable-ec_nistp_64_gcc_128 (if you're on x86-64) to use the agl/Emilia
Kasper optimised secp224r1/secp256r1/secp521r1 routines, because
they're not on by default.

Or try the 1.0.2 trunk for Intel's even faster AVX2 assembly routines.

You will need to make sure it's using the correct library version.

P256 can go at least twice as fast as that, and then some, and that
should be about what you're seeing.

Brainpool, unfortunately, just can't go that fast; the pseudo-random
primes don't have a structure which allows optimisation. But if a
generic multiplier is OK for your performance needs (like you're using
here, or if you have hardware which can do it well), Brainpool will be
okay.

- -- 
/akr.
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