19 Apr
2005
19 Apr
'05
10:42 a.m.
My understanding is that one of the specifications for removing secure
information from a hard disk requires writing zeros to the disk six or
seven times. Norton Utilities (old version) had diskwipe and filewipe
where you could specify how many times to write to the disk.
Some time ago, there was a discussion of how to recover data that had
been overwritten. The only thought I have is that it would take some
specialized equipment to read the disk and would take the hysterisis of
writing to the disk into account. My guess is that the magnetic field
would be such that after six or seven writes, the prior data would no
longer be recoverable.
Which brings up another thought. how would one
go about making sure
that data is securely wiped from a drive of a classic machine, without
physically destroying it? So it could be donated & reused?
--
--- Dave Woyciesjes
19 Apr
19 Apr
12:03 p.m.
My understanding is that one of the specifications for
removing secure
information from a hard disk requires writing zeros to the disk six or
seven times. Norton Utilities (old version) had diskwipe and filewipe
where you could specify how many times to write to the disk.
Some time ago, there was a discussion of how to recover data that had
been overwritten. The only thought I have is that it would take some
specialized equipment to read the disk and would take the hysterisis of
writing to the disk into account. My guess is that the magnetic field
would be such that after six or seven writes, the prior data would no
longer be recoverable.
It is thought that NO amount of reading and writing will completely
scramble a disk. There is a reason why the NSA/CIA/FBI/military
disintegrates their disks.
William Donzelli
aw288 at osfn.org
20 Apr
20 Apr
12:51 p.m.
William Donzelli wrote:
It is thought that NO amount of reading and writing
will
completely scramble a disk. There is a reason why the
NSA/CIA/FBI/military disintegrates their disks.
Which is why the FBI, NSA and CIA are still sharing that 20MB
drive they purchased in 1989 to store their combined 80PB
databases :-)
It's quite obvious why they often shred their disks: if their
is a non-zero risk that some other procedure might lead to
WW3 (or worse yet, a significant career hit for the security
officer involved) exactly which option do you think they
might pick? In addition, exhibiting any sign of a lack of
elevated levels of paranoia in such a position is quite
possibly an even greater career risk than developing a
sense of humour!
It's also probably cheaper to destroy the disk than to
follow any fixed wiping procedure.
Antonio
--
---------------
Antonio Carlini arcarlini at iee.org
6970
days inactive
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