Re: gbde blackening feature - how can on disk keys be "destroyed" thoroughly?

On Friday 03 September 2004 07:18 pm, David Kreil wrote:
> Dear Vijay,
>
> > I guess I took this off the list. It's OT, in my oppinion.
>
> Oh. Anywhere more appropriate to send it to that you could suggest at all?
> Now also trying freebsd-geom - would that have been the better place to
> send this to to start with?
>
> > I don't know much of anything about data recovery. But, if you can
> > recover data under 20 layers of random writes or 20 iterations of 0s,
> > then how *can* you wipe a hard drive? Short, preferably, of setting fire
> > to it :D
>
While i am not an expert in this area, I can not help but wonder---
Who are you worried about recovering the data, under what
circumstances?  My best guess is that recovering anything from
even _one_ data over-write is going to require that the recoverer have
physical posession of the drive and very sophisticated equipment
indeed.  That means they have to be some branch of a govermnment.
If you are going to attract attention of that caliber there are likely a lot
of other easier means of finding out what you are up to.  Otherwise, a
good hot fire ought to be pretty final even for the CIA.
   -LenZ-
> Sigh, tricky, yes. Apparently wiping with >20 repeats of random noise does
> the trick (say from /dev/random or arc4random generated). The difficulty
> with modern file systems / operating systems / disk drives is actually
> getting the patterns written to the magnetic media.
>
> I'm writing to the list because both assessing whether there really is a