From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: ebiggers@kernel.org
Cc: Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
linux-fscrypt@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
LKML <linux-kernel@vger.kernel.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Paul Crowley <paulcrowley@google.com>,
Greg Kaiser <gkaiser@google.com>,
Michael Halcrow <mhalcrow@google.com>,
samuel.c.p.neves@gmail.com, tomer.ashur@esat.kuleuven.be,
Eric Biggers <ebiggers@google.com>,
"Daniel J . Bernstein" <djb@cr.yp.to>
Subject: Re: [RFC PATCH 3/9] crypto: chacha20-generic - refactor to allow varying number of rounds
Date: Tue, 7 Aug 2018 01:16:18 +0200 [thread overview]
Message-ID: <CAHmME9rbe6eT6dkUqKnp-GxcqGrp-tvMfTMr8kZtsn=S3cmP8A@mail.gmail.com> (raw)
In-Reply-To: <20180806223300.113891-4-ebiggers@kernel.org>
Hey Eric,
On Tue, Aug 7, 2018 at 12:35 AM Eric Biggers <ebiggers@kernel.org> wrote:
> In preparation for adding XChaCha12 support, rename/refactor
> chacha20-generic to support different numbers of rounds.
I'm interested in learning the motivation behind going with ChaCha12.
So far, the vast majority of users of ChaCha have been getting along
quite fine with ChaCha20 and enjoying the very large security margin
this provides. In some ways, introducing ChaCha12 into the ecosystem
feels like a bit of a step backwards, even if it probably still
provides adequate security (though ChaCha8 probably shouldn't be used
or included at all). I realize the simple answer is just, "because
it's faster." But I'm wondering specifically about the speed
requirements and on what hardware and in what circumstances you found
ChaCha20 was too slow, and if this is the kind of circumstance you
expect to persist into the future.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason@zx2c4.com (Jason A. Donenfeld)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 3/9] crypto: chacha20-generic - refactor to allow varying number of rounds
Date: Tue, 7 Aug 2018 01:16:18 +0200 [thread overview]
Message-ID: <CAHmME9rbe6eT6dkUqKnp-GxcqGrp-tvMfTMr8kZtsn=S3cmP8A@mail.gmail.com> (raw)
In-Reply-To: <20180806223300.113891-4-ebiggers@kernel.org>
Hey Eric,
On Tue, Aug 7, 2018 at 12:35 AM Eric Biggers <ebiggers@kernel.org> wrote:
> In preparation for adding XChaCha12 support, rename/refactor
> chacha20-generic to support different numbers of rounds.
I'm interested in learning the motivation behind going with ChaCha12.
So far, the vast majority of users of ChaCha have been getting along
quite fine with ChaCha20 and enjoying the very large security margin
this provides. In some ways, introducing ChaCha12 into the ecosystem
feels like a bit of a step backwards, even if it probably still
provides adequate security (though ChaCha8 probably shouldn't be used
or included at all). I realize the simple answer is just, "because
it's faster." But I'm wondering specifically about the speed
requirements and on what hardware and in what circumstances you found
ChaCha20 was too slow, and if this is the kind of circumstance you
expect to persist into the future.
Jason
next prev parent reply other threads:[~2018-08-06 23:16 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-06 22:32 [RFC PATCH 0/9] crypto: HPolyC support Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 1/9] crypto: chacha20-generic - add HChaCha20 library function Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 2/9] crypto: chacha20-generic - add XChaCha20 support Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 3/9] crypto: chacha20-generic - refactor to allow varying number of rounds Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 23:16 ` Jason A. Donenfeld [this message]
2018-08-06 23:16 ` Jason A. Donenfeld
2018-08-06 23:47 ` Paul Crowley
2018-08-06 23:48 ` Paul Crowley
2018-08-06 23:48 ` Paul Crowley
2018-08-07 0:15 ` Jason A. Donenfeld
2018-08-07 0:15 ` Jason A. Donenfeld
2018-08-07 1:06 ` Paul Crowley
2018-08-07 1:06 ` Paul Crowley
2018-08-07 10:21 ` Samuel Neves
2018-08-07 10:21 ` Samuel Neves
2018-08-07 21:51 ` Eric Biggers
2018-08-07 21:51 ` Eric Biggers
2018-08-08 0:15 ` Eric Biggers
2018-08-08 0:15 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 4/9] crypto: chacha - add XChaCha12 support Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 5/9] crypto: arm/chacha20 - add XChaCha20 support Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 6/9] crypto: arm/chacha20 - refactor to allow varying number of rounds Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 7/9] crypto: arm/chacha - add XChaCha12 support Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-06 22:32 ` [RFC PATCH 8/9] crypto: arm/poly1305 - add NEON accelerated Poly1305 implementation Eric Biggers
2018-08-06 22:32 ` Eric Biggers
2018-08-07 12:09 ` Ard Biesheuvel
2018-08-07 12:09 ` Ard Biesheuvel
2018-08-07 12:09 ` Ard Biesheuvel
2018-08-07 23:19 ` Eric Biggers
2018-08-07 23:19 ` Eric Biggers
2018-08-07 23:19 ` Eric Biggers
2018-08-22 10:00 ` Ard Biesheuvel
2018-08-22 10:00 ` Ard Biesheuvel
2018-08-22 10:00 ` Ard Biesheuvel
2018-08-06 22:33 ` [RFC PATCH 9/9] crypto: hpolyc - add support for the HPolyC encryption mode Eric Biggers
2018-08-06 22:33 ` Eric Biggers
2018-08-06 23:04 ` [PATCH] crypto: remove speck Jason A. Donenfeld
2018-08-06 23:04 ` Jason A. Donenfeld
2018-08-07 1:03 ` Jeffrey Walton
2018-08-07 1:03 ` Jeffrey Walton
2018-08-07 20:18 ` Eric Biggers
2018-08-07 20:18 ` Eric Biggers
2018-08-07 1:19 ` Eric Biggers
2018-08-07 1:19 ` Eric Biggers
2018-08-07 2:38 ` Jason A. Donenfeld
2018-08-07 2:38 ` Jason A. Donenfeld
2018-08-07 3:12 ` Eric Biggers
2018-08-07 3:12 ` Eric Biggers
2018-08-07 3:12 ` Eric Biggers
2018-08-07 3:15 ` Theodore Y. Ts'o
2018-08-07 3:15 ` Theodore Y. Ts'o
2018-08-07 3:15 ` Theodore Y. Ts'o
2018-08-07 12:51 ` Ard Biesheuvel
2018-08-07 12:51 ` Ard Biesheuvel
2018-08-07 12:51 ` Ard Biesheuvel
2018-08-07 6:22 ` [PATCH v2] crypto: remove Speck Jason A. Donenfeld
2018-08-07 6:22 ` Jason A. Donenfeld
2018-08-07 6:57 ` Ard Biesheuvel
2018-08-07 6:57 ` Ard Biesheuvel
2018-08-07 6:57 ` Ard Biesheuvel
2018-09-04 4:55 ` Herbert Xu
2018-09-04 4:55 ` Herbert Xu
2018-09-04 4:55 ` Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAHmME9rbe6eT6dkUqKnp-GxcqGrp-tvMfTMr8kZtsn=S3cmP8A@mail.gmail.com' \
--to=jason@zx2c4.com \
--cc=djb@cr.yp.to \
--cc=ebiggers@google.com \
--cc=ebiggers@kernel.org \
--cc=gkaiser@google.com \
--cc=herbert@gondor.apana.org.au \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-fscrypt@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mhalcrow@google.com \
--cc=paulcrowley@google.com \
--cc=samuel.c.p.neves@gmail.com \
--cc=tomer.ashur@esat.kuleuven.be \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.