Irving Kimura <irving_kimura@lycos.com> writes:



]I suppose that I could just reformat a hard disk if I want to erase
]its contents, but my understanding is that it may be possible for
]someone intent on doing it to still recover at least some of the
]data. There's a lot of highly sensitive data in this disk I want
]to dispose of. Is there a program that will truly wipe a whole
]hard disk clean?

]Thanks in advance!


Depends on what you want. If you are satisfied with just actually
erasing the data (reformating leaves all the data there for anyone to
pick up), then reformat the disk as one large partition, and then open a
file on that partition and fill up the whole disk with whatever data you
like. This will overwrite the data on the disk. However, this may not be
enough if your attacker is really determined (eg willing to take apart
the disk and scan the disk platters to try to get off the data). There
exist cryptographic wipes which rewrite to the disk multiple times with
different bit patterns to make it harder to do that kind of work.
On the other hand, if your attacker is willing to go to that kind of
expense, then your best bet is probably physical destruction. Wipe the
disk, and then heat the platters up beyond the neal point for the
material (red hot will certainly do it).

Ie, what level of attack are you willing to guard against.
Note that all those backups you make over the years are just as
dangerous, and a lot lot easier to steal (if the hard disk went missing,
you would probably notice, if a backup tape did, you probably would not)