Heinz-Juergen 'Tom' Keller wrote:
> > A company called "Ontrack" claimed that they were capable of reading datas
> > on drive after several format.
> >
> I'm not shure if this was mentioned here before. But there is a suite
> of tools called secure_delete at the THC site (http://r3wt.base.org).
> Author: (c) 1997-99 by van Hauser / THC <[EMAIL PROTECTED]>
> It is based on the findings of Peter Gutman presented at usenix6.
> Looks interesting to me. The claim is to make recovery of the data
> impossible. If the time required for the process where a measure of
> quality it should be good ;-).
there's a variety of problems in erasing data, most if which can be
handled by software (disabling caching), some if which not (I understand
some drives have internal caches that only the firmware can
enable/disable).
the worst problem is residual magnetism. you don't hit the exact same
molecules every time, so some of them remain with the old data. put
enough money and equipment on it and you can recover not only erased
data, but several prior "incarnations" of it.
most wipe tools work by repeatedly overwriting the data section with 0s,
1s and random garbage. if done right, this provides a considerable
safety, but no guarantee. if your life depends on the data being gone,
shred the disk and burn the remains.
