From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: Congratulations! we have got hash function screwed up Date: Fri, 21 Jan 2005 12:31:50 +0300 Message-ID: <41F0CC06.3060304@namesys.com> References: <77912E9FD42896419D1CEF15E1C397A58AFCF1@london.jaguarfreightservices.local> <20041230235911.4911a20c.hihone@bigpond.net.au> <41D42F93.9060107@namesys.com> <2f4958ff050118131714f5411c@mail.gmail.com> <41EE859D.3020305@namesys.com> <41EFAFB0.2000606@namesys.com> <2f4958ff050120154330188420@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <2f4958ff050120154330188420@mail.gmail.com> List-Id: Content-Type: text/plain; charset="windows-1252"; format="flowed" To: =?UTF-8?B?R3J6ZWdvcnogSmHFm2tpZXdpY3o=?= Cc: Hans Reiser , Matthias Andree , hihone@bigpond.net.au, reiserfs-list@namesys.com Grzegorz Ja=C5=9Bkiewicz wrote: >All I know is that xxtea is fixed tea algo. If that fixes weakness in >crypto algo, than so it should make hashing better. > =20 > Not necessary. The xtea, xxtea don't fix mixing portion of tea in=20 accordance with the following papers: http://algolist.manual.ru/defence/well_known/tea.zip >No doubt there is no ideal hash algo, but if base algo has weaknes, >using fixed one only can be better, Right ? > > =20 > Nop ;) We don't need to keep a track of teacore upgrades against the attacks=20 that allow to reveal secret key. Tea hash uses tea algorithm only for mixing, not for private ciphering,=20 so plain text is known (this is hardcoded vector u32 k[] =3D { 0x9464a485, 0x542e1a94}), keys=20 (constructed by names) are known, output values are known. Nothing to reveal - nothing to upgrade.. Edward.