From owner-cvs-all Mon May 27 5:20:16 2002 Delivered-To: cvs-all@freebsd.org Received: from storm.FreeBSD.org.uk (storm.FreeBSD.org.uk [194.242.139.170]) by hub.freebsd.org (Postfix) with ESMTP id BA67B37B406; Mon, 27 May 2002 05:20:08 -0700 (PDT) Received: from storm.FreeBSD.org.uk (uucp@localhost [127.0.0.1]) by storm.FreeBSD.org.uk (8.12.3/8.12.3) with ESMTP id g4RCK7Nt005049; Mon, 27 May 2002 13:20:07 +0100 (BST) (envelope-from mark@grimreaper.grondar.org) Received: (from uucp@localhost) by storm.FreeBSD.org.uk (8.12.3/8.12.3/Submit) with UUCP id g4RCK73u005043; Mon, 27 May 2002 13:20:07 +0100 (BST) Received: from grimreaper.grondar.org (localhost [127.0.0.1]) by grimreaper.grondar.org (8.12.3/8.12.3) with ESMTP id g4RCJWCa045273; Mon, 27 May 2002 13:19:32 +0100 (BST) (envelope-from mark@grimreaper.grondar.org) Message-Id: <200205271219.g4RCJWCa045273@grimreaper.grondar.org> To: Doug Rabson Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/conf files src/sys/geom geom_aes.c References: <200205271031.15065.dfr@nlsystems.com> In-Reply-To: <200205271031.15065.dfr@nlsystems.com> ; from Doug Rabson "Mon, 27 May 2002 10:31:14 BST." Date: Mon, 27 May 2002 13:19:32 +0100 From: Mark Murray Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > All sectors are encrypted with AES in CBC mode using a constant key, > > currently compiled in and all zero. > > Isn't this a bit pointless. The on-disk data structures are so predictable > that you have any number of known-plaintext attacks against this. The only > point to encryption at this level is to protect data against physical access > to the drive and this doesn't seem to be able to do that... Not really. Having known-plaintext gives you and angle for a Differential Cryptanalysis attack, but you still need to recover a key (which if your cipher is good enough, should still be hard(tm)). There is often an element of known-plaintext in attacking someone's encrypted data; this may be easier here, so one needs to be that much more careful about changing keys (often) and wiping out in-core data of a sensitive nature. M -- o Mark Murray \_ O.\_ Warning: this .sig is umop ap!sdn To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message