From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 17 Aug 2001 14:51:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 17 Aug 2001 14:51:23 -0400 Received: from femail30.sdc1.sfba.home.com ([24.254.60.20]:55457 "EHLO femail30.sdc1.sfba.home.com") by vger.kernel.org with ESMTP id ; Fri, 17 Aug 2001 14:51:18 -0400 Content-Type: text/plain; charset=US-ASCII From: Nicholas Knight Reply-To: tegeran@home.com To: Adrian Cox , root@chaos.analogic.com Subject: Re: Encrypted Swap Date: Fri, 17 Aug 2001 11:51:08 -0700 X-Mailer: KMail [version 1.2] Cc: linux-kernel@vger.kernel.org In-Reply-To: <3B7D5603.8080805@humboldt.co.uk> In-Reply-To: <3B7D5603.8080805@humboldt.co.uk> MIME-Version: 1.0 Message-Id: <01081711510800.00814@c779218-a> Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 17 August 2001 10:36 am, Adrian Cox wrote: > Richard B. Johnson wrote: > > ** At this instant, you just killed everything in RAM with precharge > > ** > > I've done a bit more reading. The documentation I have here suggests > the precharge doesn't erase all of memory. Precharge copies from the > sense amplifiers back into the current row. The erasure is a result of > the sense amplifiers losing their contents faster than the memory > cells, but even so only one of the 2^12 rows gets erased. Now that we've established that SDRAM doesn't neccisarily get erased from rebooting, does anyone know how long it takes for SDRAM to clear after losing power? It seems to me that the fact that the RAM isn't neccisarily wiped by the BIOS at boot is less important than wether or not shutting down the system and having it shut down for 10 minutes causes the RAM to be cleared so that any intruder/thief would be unable to get the information neccisary to decrypt the swap...