Messages in this thread | | | From | Steffen Grunewald <> | Subject | Re: Wanted: Secure-delete utility for Linux | Date | Tue, 22 Dec 1998 10:36:19 +0100 (MET) |
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Dave Cinege wrote: |> |> Shail Bains wrote: |> > |> > Dunno of an equivalent for WipeDisk, though... |> |> dd if=/dev/zero of=/dev/hdX : > |> |> To be really sure I think that should be followed by /dev/urandom |> then zero again.
Why urandom ? The safest way to destroy all information on disk should be to reverse _all_ magnetic particles (flip and flip back) |> |> AFAIK DoD military grade wiping is zero->random->zero->random->zero.
A better scheme would be 10101010 - 01010101 - 11111111 - 00000000
BUT:
if I write a bit pattern to the disk - how is it stored ? Remember, CD data are re-encoded to avoid long 1 or 0 patterns. I'd guess, with fuzzy bit stuffing nowadays harddisk use similar techniques... so perhaps a "all ones / all zeroes" pattern is re-encoded to something that is near ...01010101010...
-- Steffen Grunewald = steffen(at)gfz-potsdam.de = fax +49-331-288-1266 My opinions are mine. You can rent them. Just ask me for prices :-) "Art is a lie which makes us realize the truth" - Pablo Picasso
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