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In-Reply-To: <CAGa2bXbvB7VBEBr89z3Ejbp3ZVLtqiQqnSQ3sspfBwV0L_k2TA@mail.gmail.com>
Date: Mon, 3 Apr 2017 13:44:24 +0200
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To: Yasuo Ohgaki <yohgaki@ohgaki.net>
X-Mailer: Apple Mail (2.3273)
Subject: Re: [PHP-DEV] SHA3 is very slow
From: cschneid@cschneid.com (Christian Schneider)

Am 01.04.2017 um 05:12 schrieb Yasuo Ohgaki <yohgaki@ohgaki.net>:
> I noticed that our SHA-3 is inefficient.
>=20
> =3D=3D=3D Ruby SHA3-256 =3D=3D=3D
> [yohgaki@dev ~]$ cat t2.rb
> #!/usr/bin/env ruby
>=20
> require 'digest/sha2'
>=20
> $i =3D 1000000
> until $i do
> 	Digest::SHA3.hexdigest("abcdedf", 256)
> 	$i -=3D 1
> end

Two things I noticed:
1) As far as I understand Ruby (and as far as I tested it) this does not =
execute the function at all. You probably mean something like
	while $i > 0 do

2) For some reason the Ruby implementation yields different results, I =
didn't track down why.
	- hash("sha3-256", "abc"); =3D>  =
3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532
	  which matches the test vector at =
http://www.di-mgt.com.au/sha_testvectors.html
	- Digest::SHA3.hexdigest("abc", 256) =3D> =
4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45

For whatever reason this is, it means that you can't really compare =
those two functions.

Regards,
- Chris