Gutman Method on Empty Space

[Marc Silver]

Hi there,

On Thu, Jan 17, 2008 at 09:43:46AM +0100, Wojciech Puchar wrote:
> how? even single write is enough

Not according to the paper that Gutmann wrote:
	http://www.usenix.org/publications/library/proceedings/sec96/full_papers/gutmann/

In short, he says that if you know how the data itself was overwritten
it can be recovered.  If I recall, the DoD standard for the deletion of
data is to overwrite it 3 times.  

Obviously it all comes down to how important the data is that you're
removing, but a single write is not enough if the data needs to be
disposed of 'securely'.

Cheers,
Marc