Re: [secdir] Sector review of draft-josefsson-scrypt-kdf-03

Simon Josefsson <simon@josefsson.org> Fri, 20 November 2015 12:31 UTC

Return-Path: <simon@josefsson.org>
X-Original-To: secdir@ietfa.amsl.com
Delivered-To: secdir@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A3F261B2F71 for <secdir@ietfa.amsl.com>; Fri, 20 Nov 2015 04:31:13 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.551
X-Spam-Level:
X-Spam-Status: No, score=-1.551 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HELO_EQ_SE=0.35, SPF_PASS=-0.001] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Lj-JYsADGlHM for <secdir@ietfa.amsl.com>; Fri, 20 Nov 2015 04:31:12 -0800 (PST)
Received: from duva.sjd.se (duva.sjd.se [IPv6:2001:9b0:1:1702::100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 421C01B2F72 for <secdir@ietf.org>; Fri, 20 Nov 2015 04:31:12 -0800 (PST)
Received: from latte.josefsson.org ([155.4.17.2]) (authenticated bits=0) by duva.sjd.se (8.14.4/8.14.4/Debian-4) with ESMTP id tAKCUvT8007789 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NOT); Fri, 20 Nov 2015 13:30:58 +0100
From: Simon Josefsson <simon@josefsson.org>
To: Joseph Salowey <joe@salowey.net>
References: <CAOgPGoBY9V-z5emqU6e=2QCGb_wfEUM-eE+KKgzDqg9jLAYVVw@mail.gmail.com>
OpenPGP: id=54265E8C; url=http://josefsson.org/54265e8c.txt
X-Hashcash: 1:22:151120:joe@salowey.net::hstlY10rnvrX4VVq:rBX
X-Hashcash: 1:22:151120:secdir@ietf.org::BheGs5upi5R1YxFJ:1qG3
X-Hashcash: 1:22:151120:draft-josefsson-scrypt-kdf.all@tools.ietf.org::J7Rr54B8OvB3ND7Y:8GKv
X-Hashcash: 1:22:151120:iesg@ietf.org::2gqY3Y0l1sA2KPlS:BZUp
Date: Fri, 20 Nov 2015 13:30:56 +0100
In-Reply-To: <CAOgPGoBY9V-z5emqU6e=2QCGb_wfEUM-eE+KKgzDqg9jLAYVVw@mail.gmail.com> (Joseph Salowey's message of "Sun, 13 Sep 2015 16:36:29 -0700")
Message-ID: <878u5shmyn.fsf@latte.josefsson.org>
User-Agent: Gnus/5.130014 (Ma Gnus v0.14) Emacs/24.4 (gnu/linux)
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-="; micalg="pgp-sha256"; protocol="application/pgp-signature"
X-Virus-Scanned: clamav-milter 0.98.7 at duva.sjd.se
X-Virus-Status: Clean
Archived-At: <http://mailarchive.ietf.org/arch/msg/secdir/B-dH2r5Todwt4au8GPjlIFcJWlE>
Cc: draft-josefsson-scrypt-kdf.all@tools.ietf.org, secdir <secdir@ietf.org>
Subject: Re: [secdir] Sector review of draft-josefsson-scrypt-kdf-03
X-BeenThere: secdir@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Security Area Directorate <secdir.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/secdir>, <mailto:secdir-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/secdir/>
List-Post: <mailto:secdir@ietf.org>
List-Help: <mailto:secdir-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/secdir>, <mailto:secdir-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 20 Nov 2015 12:31:13 -0000

Hi Joseph.  Thanks for your review, and sorry for the delay in answering
this.  In the new version [1] I have added a new section to discuss
scrypt parameters.

/Simon

[1] https://tools.ietf.org/html/draft-josefsson-scrypt-kdf-04

Joseph Salowey <joe@salowey.net> writes:

> I have reviewed this document as part of the security directorate's ongoing
> effort to review all IETF documents being processed by the IESG.  These
> comments were written primarily for the benefit of the security area
> directors and document authors.
>
> I think this document is ready with issues.   The document describes a
> password to key function, scrypt, based on memory hard functions to make it
> more expensive and difficult to develop specialized hardware to obtain the
> password from a recovered key.  I'd like to see this document published.  A
> few issues are listed below.
>
> First, I think Paul Kyzivat's GenArt review.
> http://mailarchive.ietf.org/arch/msg/gen-art/fToZiioHo-6x5ZRQWNcTr-aUYVk
> <https://mailarchive.ietf.org/arch/msg/gen-art/fToZiioHo-6x5ZRQWNcTr-aUYVk>,
> raised
> some points that could help the readability of the document.
>
> Second, the script algorithm has several parameters, but the document has
> very little discussion on how to choose those parameters or what they
> affect (this is also pointed out in Paul's message).  It would be good to
> have some discussion or guidance for parameter selection in the security
> considerations.
>
> Cheers,
>
> Joe
> _______________________________________________
> secdir mailing list
> secdir@ietf.org
> https://www.ietf.org/mailman/listinfo/secdir
> wiki: http://tools.ietf.org/area/sec/trac/wiki/SecDirReview
>