From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: ** X-Spam-Status: No, score=2.0 required=5.0 tests=AWL,DNS_FROM_RFC_ABUSE, DNS_FROM_RFC_POST,DNS_FROM_RFC_WHOIS autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail1-relais-roc.national.inria.fr (mail1-relais-roc.national.inria.fr [192.134.164.82]) by yquem.inria.fr (Postfix) with ESMTP id 9CBADBBAF for ; Mon, 1 Dec 2008 14:47:25 +0100 (CET) X-IronPort-AV: E=Sophos;i="4.33,695,1220220000"; d="scan'208";a="20603958" Received: from concorde.inria.fr ([192.93.2.39]) by mail1-smtp-roc.national.inria.fr with ESMTP; 01 Dec 2008 14:47:25 +0100 Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id mB1DlPkF004037 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Mon, 1 Dec 2008 14:47:25 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ai4BAN95M0lDww/TmWdsb2JhbACOJ4UkAQEBAQEICwoHEbBJim0FAgGCeg X-IronPort-AV: E=Sophos;i="4.33,695,1220220000"; d="scan'208";a="32027031" Received: from web111514.mail.gq1.yahoo.com ([67.195.15.211]) by mail4-smtp-sop.national.inria.fr with SMTP; 01 Dec 2008 14:47:24 +0100 Received: (qmail 25484 invoked by uid 60001); 1 Dec 2008 13:47:23 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=tN19gBqViAKRpdxkyHT+y0VWojhn9qfaQJRzl5d67QLF1OsvEZyonBcE+p369ggSPwd+8beEIKI5b6IjWjleoWXBGCHiJBFQl/JMX8204D0Y4aejtgmv6NrFur3qaqZs6nhTfvvDfj9APqNOqsoDNoACMCukapD+dUjQ78NAtSo=; X-YMail-OSG: ONwcgYQVM1kRq8qo7zwJgSSmeuQtFE8N3QFCElladqzR_K3nfdfxwhEce0dD_ufbEF.if0.GXob1M0A_dYXsVugW3pp4VuAXVBIOPxHhxP5pSCCSNU89zO7cU6NrMJFaIjEIS59Rs_kIyth5dx8KlbPi1RFr0ACfz.ujwI5LCF3x.5E- Received: from [213.205.71.56] by web111514.mail.gq1.yahoo.com via HTTP; Mon, 01 Dec 2008 05:47:22 PST X-Mailer: YahooMailWebService/0.7.260.1 Date: Mon, 1 Dec 2008 05:47:22 -0800 (PST) From: Dario Teixeira Subject: Re: [Caml-list] Computing with big numbers? To: caml-list@inria.fr, Alan Schmitt In-Reply-To: <1A5BFA46-376C-41BB-B357-8A7899C600C6@polytechnique.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-ID: <999499.25121.qm@web111514.mail.gq1.yahoo.com> X-Miltered: at concorde with ID 4933EAED.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; hashes:01 hashes:01 hash:01 wikipedia:01 wikipedia:01 wiki:01 cheers:01 caml-list:01 probability:01 negligible:04 bits:05 bits:05 computing:05 i'm:09 i'm:09 Hi, > In preparation for a talk I'm going to give, I wanted > to estimate how good 128 bits MD5 hashes were: how many > hashes must be taken before the probability for a collision > become non negligible? (I'm assuming equi-probability of > every hash.) I reckon that by saying "how good 128 bits MD5 hashes were" you are aware of the recent attacks that make MD5's effective security less than 128-bit. The Wikipedia has a good summary: http://en.wikipedia.org/wiki/MD5 Cheers, Dario Teixeira =0A=0A=0A