[olug] [OT] IBM Authorized service center in Lincoln...

[Christopher Cashell]

On Sun, Nov 1, 2009 at 9:21 PM, Jeff Hinrichs - DM&T <dundeemt at gmail.com> wrote:
> Gutmann is the same idea but applied to mfm/mll disks.  Writing all
> 0's once leaves the theoretical possibility of  equipment sufficiently
> advanced to detect smaller residual differences and still be able to
> make a good analysis of the disk.(some bits are not as 0 as others)
> You need to remember that magnetic field levels are not digital, but
> analog.

Note that modern disks do not use MFM/RLL encodings, and even Gutmann
has come out and said that his secure data deletion techniques have
been misused and misunderstood.  After recent criticism suggesting
that a single pass with random data or even zeros would be enough to
make recover impossible, Gutmann updated his original article on
secure deletion.  One of the last statements includes, "Any modern
drive will most likely be a hopeless task [. . .]".[1]

> Paranoid me?  Who said that? :)

I may be a little paranoid, but the engineer inside my head requires
evidence in some cases, and with modern drive recovery, there's
nothing but speculation.

> -Jeff
> +1 for DBAN

[1] http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

-- 
Christopher