Re: Deleted file retrieval

I find it intriguing that previously overwritten data can be recovered.
Assuming a hard drive has been in use for awhile, it's feasible that
the sectors where a file was stored contained previous data themselves,
even before they were overwritten. So how can it be determined exactly
which magnetic 1's and 0's are relevant?

R. McCarty wrote:
Even when a file is overwritten, there is a degree of magnetic
retentivity that can (with effort) be read. Thus previous data
has the possibility of being recovered. There are two distinct
types of recovery, Software & Hardware. To stop hardware
recovery takes numerous passes of writing alternating data to
make reading old magnetic states nearly impossible.
Personally, I use CyberScrub for drive security. I would do a
Google as there are likely several free utilities available.
For full drive erasure, many hard drive vendors provide a tool
that does what's called a "Zero Fill" - Writes Zeros to all areas
of the disk.

"Sal" <here@xxxxxxxxxxx> wrote in message
news:1147202198.261055.254050@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Can a file that's been deleted and subsequently had all it's sectors
overwritten with new data be restored to its original content? My
intuitive sense is that it cannot, but I seem to remember a thread on a
different news group where someone claimed that even if a file had been
completely overwritten numerous times, it could still be retrieved.

In light of above, is there a poor man's way (meaning without
specialized software) of rendering a deleted sensitive file
unretrievable by overwriting it's data with another file of equal or
greater size?


.

Relevant Pages

  • bugtraq@planetcobalt.net
    ... "Overwriting Hard Drive Data: The Great Wiping Controversy". ... modern ePRML drives. ... of a few regarding data recovery after a file has been 'zeroed' and ...
    (Security-Basics)
  • Re: Deleted file retrieval
    ... types of recovery, Software & Hardware. ... that does what's called a "Zero Fill" - Writes Zeros to all areas ... completely overwritten numerous times, ... unretrievable by overwriting it's data with another file of equal or ...
    (microsoft.public.windowsxp.general)
  • Re: FileCopy overwrites the existing file
    ... overwriting large file is quite expensive and if I had to do it, ... I've seen a software that allows a user to overwrite the sectors up ... overwritten once with zeros. ... I wouldn't assume such recovery is a regular offer. ...
    (microsoft.public.win32.programmer.kernel)
  • Re: what happens to deleted files
    ... It has never been done, not even by Dr. Gutmann himself, and he is the one who first advanced the theory that it might be possible to recover data from overwritten drives. ... The best that Dr. Gutmann could do with MFM was to show that there "might" be a possibility that some bits of data might be recoverable, he was never able to recover actual files and he has never been able to publicly demonstrate that he actually could recovery files on zero written drives, and nobody else either ever could. ... The reason that the US government or any other entities who work with very sensitive data might melt or destroy drives instead of securely overwriting them is not because of the possibility of data recovery on these drives, it is because of the possibility of user or software errors when doing the wiping. ... There is one area which can be of real concern with regards to wiped drives and where actual "bits" of data recovery could be made, cluster tips. ...
    (microsoft.public.windowsxp.help_and_support)
  • Re: recovering deleted data
    ... My downloads go onto a different partition from my system drive (if that's ... different location to save overwriting any data that is going to be ... MS-MVP Windows Shell/User ... recovery requires more extensive (and ...
    (microsoft.public.windowsxp.help_and_support)