From: Eric Dumazet <eric.dumazet@gmail.com>
To: George Spelvin <linux@sciencehorizons.net>
Cc: tytso@mit.edu, ak@linux.intel.com, davem@davemloft.net,
David.Laight@aculab.com, djb@cr.yp.to, ebiggers3@gmail.com,
hannes@stressinduktion.org, Jason@zx2c4.com,
jeanphilippe.aumasson@gmail.com,
kernel-hardening@lists.openwall.com,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
luto@amacapital.net, netdev@vger.kernel.org, tom@herbertland.com,
torvalds@linux-foundation.org, vegard.nossum@gmail.com
Subject: Re: HalfSipHash Acceptable Usage
Date: Tue, 20 Dec 2016 21:29:24 -0800 [thread overview]
Message-ID: <1482298164.8944.8.camel@edumazet-glaptop3.roam.corp.google.com> (raw)
In-Reply-To: <20161221032829.3031.qmail@ns.sciencehorizons.net>
On Tue, 2016-12-20 at 22:28 -0500, George Spelvin wrote:
> > I do not see why SipHash, if faster than MD5 and more secure, would be a
> > problem.
>
> Because on 32-bit x86, it's slower.
>
> Cycles per byte on 1024 bytes of data:
> Pentium Core 2 Ivy
> 4 Duo Bridge
> SipHash-2-4 38.9 8.3 5.8
> HalfSipHash-2-4 12.7 4.5 3.2
> MD5 8.3 5.7 4.7
So definitely not faster.
38 cycles per byte is a problem, considering IPV6 is ramping up.
But TCP session establishment on P4 is probably not a big deal.
Nobody would expect a P4 to handle gazillions of TCP flows (using a
32bit kernel)
What about SHA performance (syncookies) on P4 ?
Synfloods are probably the only case we might take care of for 2000-era
cpus.
next prev parent reply other threads:[~2016-12-21 5:29 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-19 17:32 HalfSipHash Acceptable Usage Jason A. Donenfeld
[not found] ` <CAGiyFdduUNSGq24zfsk0ZU=hnOCmewAw8vw6XvDoS-3f+3UPKQ@mail.gmail.com>
2016-12-19 21:00 ` Jason A. Donenfeld
2016-12-20 21:36 ` Theodore Ts'o
2016-12-20 23:07 ` George Spelvin
2016-12-20 23:55 ` Eric Dumazet
2016-12-21 3:28 ` George Spelvin
2016-12-21 5:29 ` Eric Dumazet [this message]
2016-12-21 6:34 ` George Spelvin
2016-12-21 14:24 ` Jason A. Donenfeld
2016-12-21 15:55 ` George Spelvin
2016-12-21 16:37 ` Jason A. Donenfeld
2016-12-21 16:41 ` [kernel-hardening] " Rik van Riel
2016-12-21 17:25 ` Linus Torvalds
2016-12-21 18:07 ` George Spelvin
2016-12-22 1:54 ` Andy Lutomirski
2016-12-21 14:42 ` Jason A. Donenfeld
2016-12-21 15:56 ` Eric Dumazet
2016-12-21 16:33 ` Jason A. Donenfeld
2016-12-21 16:39 ` [kernel-hardening] " Rik van Riel
2016-12-21 17:08 ` Eric Dumazet
2016-12-21 18:37 ` George Spelvin
2016-12-21 18:40 ` Jason A. Donenfeld
2016-12-21 22:27 ` Theodore Ts'o
2016-12-22 0:18 ` George Spelvin
2016-12-22 1:13 ` George Spelvin
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