Re: Resources required to retrieved wiped disk

On Tue, 23 May 2006 01:18:14 GMT, Bryan Olson
<fakeaddress@xxxxxxxxxxx> wrote:

clark wrote:
If I get the gist of your point made several times in this thread:

It is that current hard drives ,which actually have extremely high
data densities compared to drives even a few years ago, are no longer
good candidates for the kind of techniques which involve removing the
platters and examining them under "electronic microscopes" to discern
previous "writes" after the data has been "overwritten" even once.

That's my theory, so I'm trying to find evidence that would
refute it.

Did anyone demo recovery of over-written data from hard drives
of a decade ago? Two decades? What's the most recent anyone
can actually cite?

I know of no actual physical recovery. It may be folklore now.

The paper that I read on this is frrom Peter Gutmann and is 10 years
old. Here's a link:

I think this is the one everyone cites, or at least one of the main

But the actual activity he is talking about may be from the 1980's and
the difference in platter densities, drive electronics and mechanics
between then and today is huge.

I know a bit about this.

In the early 80's completely different. In my tool rig, I carried an
oscilloscope to get "index to data" and "cat's eye" and the calibrated
torque head wrenches for Western Dynex, Perkin Elmer and other drives.

When a drive crashed, I removed and replaced the fixed platter and or
the read/write heads, which were ceramic and embedded with the
instrumentation and floated on very lightweight spring steel pieces.

I think you may be right and this may technical lore now.

But if I find anything, I'll post it.