Re: Data destruction

["Benjamin J. Weiss" <benjamin birdvet org>]

Elmer E. Dow wrote:

> Greetings:
>
> This post is not RH specific, but given the experience level of the list 
> participants, it seems like the likely place to seek input on this subject. 
> If there's a more appropiate place to post, please let me know.
>
> I'm researching available data destruction programs that I could use for 
> getting rid of an organization's financial info, etc. before 
> donating/disposing/reusing an old computer. Have any of you used the 
> following programs? Good or bad experience? Any words of advice?
>
> <snip>
>  
Elmer,

It depends upon the level of confidentiality that you are concerned 
about.  I can tell you flat out that none of those methods are 
acceptible by the Department of Defense if the hard drive has at any 
time contained classified information.  Dark rumors abound about the 
ability of the NSA to recover data from a disk even if it's been 
overwritten multiple times.  Degausing may enhance your security.  All I 
can tell you is that we military security folks have to physically 
destroy the disk.  If we want to donate/surplus, etc the computer, we 
must remove the hard drive first.

That being said, your data may not be considered "classified".  In that 
case, you'll want something that writes to the disk, not to the 
partitions, and in a successive pattern of all 1's, then all 0's, then 
all 1's, etc.  I can't remember for sure, but I think that 3-5 passess 
will sufficiently neutralize the underlying magnetic patterns for most 
purposes.  If you don't mind risking damage to the disk, I'd get a 
powerful degausser and run that over the HD afterwards.  Be warned, 
though, that this has been known to sufficiently magnetize internal 
parts and render the drive useless.

I haven't used any of the tools that you mentioned in your email, but 
I've heard good things about Wipe.

Ben