Just to drag the thread on a little longer I read this bite in my
recent SANS email, thought it would be interesting reading for those
interested.
-Mike-
--Rendering Drives Completely Unreadable Can be Difficult
(20 April 2005)
The National Association for Information Destruction has said it cannot
endorse the use of wiping applications alone for ensuring that data have
been effectively removed from hard drives. NAID executive director Bob
Johnson said the only way to ensure that the data will be unreadable is
to physically destroy the drives, and even that has to be done in
certain ways to ensure its efficacy. Most major PC makers offer a drive
destruction service for $20 or $30. Some hardware engineers say they
understand why the drives have been created in a way that makes it hard
to completely erase the data: customers demanded it because they were
afraid of losing information they had stored on their drives.
http://news.com.com/2102-1029_3-5676995.html?tag=st.util.print
[Editor's Note (Pescatore): Cool, I want a "National Association for
Information Destruction" tee shirt. How hard could it be to have an
interlock feature - you can really, really clear the drive if you open
the case, hold this button down while you delete?
(Ranum): Peter Guttman, from New Zealand, did a terrific talk in 1997
at USENIX in which he showed electromicrographs of hard disk surfaces
that had been "wiped" - you could still clearly see the 1s and 0s where
the heads failed to line up perfectly on the track during the
write/erase sequence. He also pointed out that you can tell more
recently written data from less recently written data by the field
strength in the area, which would actually make it much easier to tell
what had been "wiped" versus what was persistent long-term store. The
paper, minus the cool photos may be found at:
http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html
Hard disks, I've found, make satisfying small arms targets.]
-----Original Message-----
From: Kinnell [mailto:kinnell.t@gmail.com]
Sent: Wednesday, April 27, 2005 12:28 PM
To: nc@phat.co.nz
Cc: security-basics@securityfocus.com
Subject: Re: HD memory wiper/shredder
This was more than helpful. Thank you all very much, and I'm sure
we've all found out about quite a few we didn't know about before.
thanks,
Kinnell
-----Original Message-----
From: Kinnell [mailto:kinnell.t@gmail.com]
Sent: Monday, April 25, 2005 2:06 PM
To: security-basics@securityfocus.com
Subject: HD memory wiper/shredder
Hey all.
I recently had a friend ask me if I knew of any real good file
shredders/wipers. He wants to be able to securely shred a file used
for an encryption key after it is no longer needed at that location.
I couldn't think of any off of the top of my head but I figured this
list would be a great place to start. So does anyone know of a good
shredder to use for this purpose? Freeware would be preferred.
thanks,
Kinnell
