On Sun, Jul 12, 2015 at 7:18 PM, Rich Freeman <ri...@gentoo.org> wrote:
>I think that assumes that the two get averaged together in some way
>and cannot be separated.  If you could determine the orientation of
>individual magnetic domains it is possible that you might be able to
>determine which ones are which.  For example, if in a given location
>you found 90% of the grains had one orientation, and 10% had another,
>you might be able to infer that the 10% was the previous value of that
>location.

Every bit on the disk will have this ghost inverse behind it. If you
flip bits at random - what overwriting the drive with random data
effectively does - then it's impossible to tell which ones were
flipped recently and which ones were flipped before the last write.

>That probably isn't practical with current technology, but I see no
>reason that it should be impossible.

Magnetic force microscopy has a resolution fine enough to read any
disk that can be created - they're just really expensive.


On Sun, Jul 12, 2015 at 8:50 PM, Thomas Mueller
<mueller6...@bellsouth.net> wrote:
>All that has been said on this thread supposes that the hard drive is still 
>readable and writable.

On Sun, Jul 12, 2015 at 6:22 PM, R0b0t1 <r03...@gmail.com> wrote:
>If you need to destroy a platter drive take it apart and sand the platters 
>(probably the easiest). If it's solid state heat the drive over 150C-250C for 
>an extended period of time or mechanically destroy the chips.

Reply via email to