Securely delete files...

[Chris Walters]

Werner Koch wrote:
> You cannot clear a modern drive using external software!  It doesn't
> matter what validated software algorithm you use.  Drives may reorder
> sectors on the fly, they use read and write caches and do all kind of
> tricks to squeeze out more performance.  There are even solid state
> buffers so that sometimes things won't get written to the platters at
> all.
> 
> After all there is software between you and the magnetics.  That
> software needs to allow you to do what you want but it properly won't.
> 
> Sure it is not easy to get the data directly from the platters but there
> are enough labs which can do that.  If you want to protect against this,
> plain physical force is the way to go.  It is pretty easy to open a
> drive case and use a hammer to break the platters into small pieces.
> The last time I swung my hammer onto an opened drive, it looked as if
> the platters were made up of ceramic substrate: a lot of small pieces
> hit my safety goggles.  That won't be an easy puzzle to solve.
> 
> 
> Shalom-Salam,
> 
>    Werner

I hate to tell you this, but the F.B.I. Computer Forensics Laboratory has
successfully recovered data from a drive, where the platters were shot multiple
times with a shotgun.

The only sure way to make sure no one can recover your data is to put it into a
blast furnace (this would be hot enough to melt the whole thing into a puddle,
and would cause substantial mixing between the ferro-magnetic alloy and the
titanium internal structure.

Regards,
Chris