IETF Logo Mail Archive

[Cfrg] Re: Extractors/KDF definition and goal

csjutla <csjutla@watson.ibm.com> Wed, 26 October 2005 20:11 UTC

Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1EUrc3-000707-6E; Wed, 26 Oct 2005 16:11:07 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1EUrc1-0006zu-9U for cfrg@megatron.ietf.org; Wed, 26 Oct 2005 16:11:05 -0400
Received: from ietf-mx.ietf.org (ietf-mx [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id QAA24574 for <cfrg@ietf.org>; Wed, 26 Oct 2005 16:10:49 -0400 (EDT)
Received: from igw2.watson.ibm.com ([129.34.20.6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1EUrpD-0001WY-JB for cfrg@ietf.org; Wed, 26 Oct 2005 16:24:44 -0400
Received: from sp1n293en1.watson.ibm.com (sp1n293en1.watson.ibm.com [129.34.20.41]) by igw2.watson.ibm.com (8.12.11/8.13.1/8.13.1-2005-04-25 igw) with ESMTP id j9QKCh8c018748; Wed, 26 Oct 2005 16:12:43 -0400
Received: from sp1n293en1.watson.ibm.com (localhost [127.0.0.1]) by sp1n293en1.watson.ibm.com (8.11.7-20030924/8.11.7/01-14-2004_2) with ESMTP id j9QKAoF235334; Wed, 26 Oct 2005 16:10:50 -0400
Received: from mgsmtp00.watson.ibm.com (mgsmtp00.watson.ibm.com [9.2.40.58]) by sp1n293en1.watson.ibm.com (8.11.7-20030924/8.11.7/01-14-2004_1) with ESMTP id j9QKAn4316646; Wed, 26 Oct 2005 16:10:49 -0400
Received: from wasa.watson.ibm.com (wasa.watson.ibm.com [9.2.16.192]) by mgsmtp00.watson.ibm.com (8.12.11/8.12.11/2005/09/01) with ESMTP id j9QK8IYE003814; Wed, 26 Oct 2005 16:08:18 -0400
Received: (from csjutla@localhost) by wasa.watson.ibm.com (AIX5.1/8.11.6p2/8.11.0/03-06-2002) id j9QKAlh29792; Wed, 26 Oct 2005 16:10:47 -0400
From: csjutla <csjutla@watson.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: Wed, 26 Oct 2005 16:10:44 -0400
To: David McGrew <mcgrew@cisco.com>
In-Reply-To: <27010A5C-7C50-468A-A7F3-819D0025EEAE@cisco.com>
References: <200510260025.j9Q0Pdn4026118@taverner.CS.Berkeley.EDU> <27010A5C-7C50-468A-A7F3-819D0025EEAE@cisco.com>
X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid
Message-ID: <17247.57728.56441.144739@wasa.watson.ibm.com>
X-Spam-Score: 0.0 (/)
X-Scan-Signature: de4f315c9369b71d7dd5909b42224370
Content-Transfer-Encoding: 7bit
Cc: cfrg@ietf.org, David Wagner <daw-usenet@taverner.CS.Berkeley.EDU>
Subject: [Cfrg] Re: Extractors/KDF definition and goal
X-BeenThere: cfrg@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Crypto Forum Research Group <cfrg.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/cfrg>, <mailto:cfrg-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:cfrg@ietf.org>
List-Help: <mailto:cfrg-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/cfrg>, <mailto:cfrg-request@ietf.org?subject=subscribe>
Sender: cfrg-bounces@ietf.org
Errors-To: cfrg-bounces@ietf.org

You can have deterministic extractors if you make some 
assumptions on the source. One of the most intriguing new results
is that if you have two independent sources each with certain
min-entropy, then you have a detereministic extractor. 

See Barak's homepage, or www.math.ias.edu/~boaz/Papers/BKSSW.html

Needless to say, these constructions are not very efficient.
Personally, I think SHA-1 makes a very good random oracle (despite
the recent attacks). As I point out in my recent paper
"Is SHA-1 conceptually sound?", it gets to be as good as one would
hope, and probably better than Discrete-log based "random oracles".

Charanjit



_______________________________________________
Cfrg mailing list
Cfrg@ietf.org
https://www1.ietf.org/mailman/listinfo/cfrg

v2.23.0 | Report a Bug | By Email