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RE: Suggestions on free XP hard drive wiping utilities?
From: "David Verty" <verticalrave () hotmail com>
Date: Wed, 12 Feb 2003 03:10:58 +0000

There is a whole thread on ExtremeTech about this I believe...and it stretches on for a long run. You might find some useful information there, like DoD (Department of Defense) standards, and software that exceeds it for deletation of files.

What the government does right now to permanently get rid of data is shred the disk in a metal shredder.

Are there any programs for secure deletation? Never heard of any really that were extremely good.

And i've heard of hard disks storing everything in so called 'layers' (you have to rewrite your disk three or four times+ with phony data to truly get rid of everything.) but the edge thing is something i've never heard about. Interesting. Somebody on ExtremeTech also mentioned that since the signals are theoretically magnetic, its possible to extract the strength of the previous magnetic signal (though weak) and rebuild the data from there. Whatever validity that has i'm not so sure.

From: "MacFerrin, Ken" <Ken_MacFerrin () csgsystems com>
To: <security-basics () securityfocus com>
Subject: RE: Suggestions on free XP hard drive wiping utilities?
Date: Tue, 11 Feb 2003 11:20:16 -0600

There are dozens of tools that will "clean" your hard drive by overwriting your data in various patterns and such and most any of those will give you "decent" security, but.. none of those are going to make the data irretrievable to someone with the right equipment.

I'm no expert but the basics of being able to retrieve data stem from the fact that when the HDD head overwrites the data it's never able to perfectly write along the same track that it did when writing the original data. This leaves an "edge" of data that wasn't quite overwritten and that "edge" is enough for someone with a basic setup (about 1500 USD) of specific equipment to go back and pull the original 1's and 0's off the disk.. The only way to truly "clean" the disk is using equipment specifically designed to drive the head at a higher voltage to create a wider write track and re-write random patterns many times. From what I understand though even these re-writes will leave some residue that could be picked up by some high-end gear and a skilled operator.

Essentially, if the data was really that sensitive, you need to physically destroy the disk..

-----Original Message-----
From: Joris De Donder [mailto:joris () digitaldefense be]
Sent: Tuesday, February 11, 2003 6:21 AM
To: 'security-basics () securityfocus com'
Cc: Champion, Steve
Subject: Suggestions on free XP hard drive wiping utilities?

> Would someone please throw out a URL and suggestions for free Windows XP,
> hard drive wiping utility's?


  "Eraser is a secure data removal tool, which allows you to remove
   sensitive data from your hard drive by overwriting it with carefully
   selected patterns.

   The program is free software, which means that everyone has
   access to the source code,..."

Joris De Donder

MSN 8 with e-mail virus protection service: 2 months FREE* http://join.msn.com/?page=features/virus

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