[H-GEN] dd or shred for secure deletes.

[Clinton Roy]

>  So I was wondering if anyone knows the difference between the dd and shred
> methods of deleting files and hard drives and what the best way is.

shred does the dd 25 times over :)

There are so many levels of indirections from a high level filesystem
to hunks of metal on a hard drive that it's basically impossible to
know where a file is going to be placed on a disk.

The problem shred tries to fix is a physical one, that off the
physical media being able to remember it's previous states, if you've
got sensitive enough equipment to listen hard enough.

I'd actually be surprised if a regular ext3 filesystem would stop
shred from working, as the default is to only journal metadata, not
data; but I'm happy to be proved wrong.

cheers,
--
Clinton Roy
www.acqao.org - ARC Centre of Excellence for Quantum-Atom Optics
www.humbug.org.au  - Brisbane Unix Group
azure.humbug.org.au/~croy/blog - Blog
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