Re: 'Shredding' a hard disk

[Philipp Lehman <lehman@gmx.net>]

Ivo Wever <I.J.W.Wever@student.tnw.tudelft.nl> wrote:

> Robert Waldner wrote:
>>Philipp Lehman writes:
>> >I want to sell an old machine that I don't use any more but there's
>> >still sensitive stuff like personal emails, gpg keys, and passwords on
>> >the hdd. What's the recommended way to securely 'shred' this data so
>> >that it cannot be undeleted by the next owner?
>>
>>Depends.
>>
>>But, for all practical values, a simple `dd if=dev/urandom bs=1M \
>>  of=/dev/hdX` should be quite sufficient.

> Some people advise to repeat this procedure several times. Can anyone
> explain why? I see no reason why one pass doesn't suffice.

I guess this only applies if you expect anyone to have access to some serious 
hardware-based recovery solutions. See:

http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

Thanks to all who replied. As I don't expect anyone to go after my old box 
with a magnetic force scanning tunneling microscope, I'll settle with dd ;)

-- 
Philipp Lehman  <lehman@gmx.net>


-- 
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org 
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org