Re: PC disk wipe software

-----BEGIN PGP SIGNED MESSAGE-----

In article <199510091318.JAA24166@jekyll.piermont.com>, perry@piermont.com
("Perry E. Metzger") wrote:

> I thought I'd ask here, since its related to a lot of the stuff people
> have written for the PC platform in these parts. I need to securely
> wipe a bunch of data from an MS-DOS hard drive, so that it can't be
> recovered. Are there any readily available utilities for this? Will
> any of them selectively erase only data that isn't allocated to
> existing files?

Whatever you use, check its claims with a disk editor. None of the various
wipe utilities for the Mac that I am aware of (Norton, Burn) work as
advertized. They all invariably fail to wipe the slackspace at the end of
allocated, but not fully used blocks. Consequently, several kB of data
left behind in said slackspace by previously deleted files will be missed
on your average drive.
- ---
[This message has been signed by an auto-signing service.  A valid signature
means only that it has been received at the address corresponding to the
signature and forwarded.]

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2
Comment: Gratis auto-signing service

iQBFAwUBMHmgGioZzwIn1bdtAQFEsQF8CYfksEosFfBJoQckOM390b7CBeupCtrf
T2Var/yEUwuT5lxH7xJ6y9p69wfaljtz
=Hkkv
-----END PGP SIGNATURE-----

-----BEGIN PGP SIGNED MESSAGE-----

Hello cypherpunks@toad.com
  and shamrock@netcom.com (Lucky Green)

> In article <199510091318.JAA24166@jekyll.piermont.com>, perry@piermont.com
> ("Perry E. Metzger") wrote:
 
[asking for utility to wipe data from MS-DOS hard drive]
 
shamrock@netcom.com (Lucky Green) answered:

...
> They all invariably fail to wipe the slackspace at the end of
> allocated, but not fully used blocks. Consequently, several kB of data
...

Since nobody seemed to mention it: I suspect that most of them also
fail to wipe already reallocated space.

Think about it: some of that space was only overwritten once...

So to be safe I guess make a backup (with a backup utility that doesn't
copy slackspace), wipe the disk, then restore. Also beware programs that
do not properly zero their files when allocating them.

The cliche answer to the original question, I believe, is:
  yes, go to the hardware store and ask for a 'sledgehammer'.


Hope that makes sense...

Jiri
- --
If you want an answer, please mail to <jirib@cs.monash.edu.au>.
On sweeney, I may delete without reading!
PGP 463A14D5 (but it's at home so it'll take a day or two)
PGP EF0607F9 (but it's at uni so don't rely on it too much)

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2i

iQCVAwUBMHsf0SxV6mvvBgf5AQGMmgP9GJvJgWmdW3YHRCfNRKQtlM557MIrzn+t
ZDbiSp/E7hKXPDf7Ech/O7hzdFvCCA7APR4lE9bIimP8mFuE5KAKTLIC2cYnG6Hi
Cj28OorVS/mDtwMOJJ6TJLV8tXArDtvAKY9OOghzepZs9hf9b5lXs6PXWEd7gb6F
LinHs36C4dI=
=0vcL
-----END PGP SIGNATURE-----