Security and harddisk crubbing in Linux

[Peter Barker]

On Fri, 26 Oct 2001, Anthony Wesley wrote:

> Why write random bits? Why not just zero everything with
> 
> 	... dd if=/dev/zero ...
> 
> This will run somewhat faster.

Assuming "0" maps to "magnetic field always aligned this way" on
the disc, hardware recovery tools can tell that at one stage this bit was
aligned the other way. Flipping the field, IOW, is not completed by your
average drive.

It is hoped that by randomising the data on the disk several times, you
will confuse the issue enough so no data can be recovered.

> cheers, Anthony

Yours,
-- 
Peter Barker                          |   N    _--_|\ /---- Barham, Vic 
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