[CLUE-Tech] Clear HDD of old OS, etc?

[Alex Young]

Here's a link to a good document presented to USENIX on the topic:
http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

It appears that any method of single or even double pass writing of random
data is ineffective, if you are trying to prevent people with advanced tools
from accessing the information.
If you are trying to stop a typical user from accessing data using only the
manufacturers drive electronics, dd if=/dev/random of=/dev/hdX should be
more then adequate.

Some other thoughts:
a. fdisk /mbr will only effect the boot record.    All data will still exist
on the drive.
b. encoding methods are drive dependant and consist of patterns of
"all-north" and "all-south" data, so any suggestion of writing all ones or
all zeros to the drive is basically imposable using the firmware included
with the drive.

Alex

>  -----Original Message-----
> From: 	clue-tech-admin at clue.denver.co.us@DYNEGY   On Behalf Of Dave
Price <davep at kinaole.org>
> Sent:	Friday, May 31, 2002 11:29 AM
> To:	clue-tech at clue.denver.co.us; debian-user at lists.debian.org
> Subject:	[CLUE-Tech] Clear HDD of old OS, etc?
> 
> Hi,
> 
> I am looking for a quick way to clear an HDD of old data, partitions,
> etc.
> 
> I found this on /. thru a google search:
> 
> dd if=/dev/random of=/dev/hdX
> 
> When i do this from a console shell after booting from a woody install
> disk, It does not seem to work ... i.e. I can still see the old
> partition table in fdisk ...
> 
> Is there maybe a better dd invocation ?
> 
> aloha,
> dave
> _______________________________________________
> CLUE-Tech mailing list
> CLUE-Tech at clue.denver.co.us
> http://clue.denver.co.us/mailman/listinfo/clue-tech
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