destorying the hard drive

Mike Y wrote:

Nope that's a total myth.
No drive zero-wiped to government standards has even had any data

recovered

from it.


Actually, I'd suspect the 'government standard' is a myth. As far as I
know, I've
never been able to find ANY hard reference to a standard for wiping a drive,
other than 'second/third' or a 'friend of a friend said that' kind of thing.

Which pretty well tells us a lot about your level of expertise in this
field.

US Dept of Defense Standard 5220.22-M
http://www.qsgi.com/usdod_standard_dod_522022m.htm

Before posting about hearsay and myths that you heard you should do a
bit of research.

John

"John John" wrote in message
...
Mike Y wrote:

"John John" wrote in message
...

Lee wrote:


Best advice yet is correct, but your advice on zero filled data is
totally incorrect.

No, his advice is totally correct! I challenge you, or anyone reading
these groups, to offer concrete proof that they can recover zero
written/wiped files or to give us the names of data recovery firms who
can do it.

It cannot be done, it has never been done, no one has ever been able to
do it and no one has ever been able to offer a shred of evidence that
they have successfully recovered files on securely wiped disks.

John



Special hardware can could overwritten data. Either with an analog
analysis or looking for bit shifts. Don't get confused in thinking that
digital is digital, it's still an analog media...

That is not true, there is no such magical machine available at any cost
that can recover data on securely wiped (zero filed) drives. No one can
recover data on properly wiped drives, the notion that it can be done is
nothing more than a myth.

John

Well, when you say securely wiped, by that meaning multiple wipes, I agree.
(The most secure is to wipe multiple times with multiple and DIFFERENT
data)

Also, if you imply that there exists no machine that interfaces to the IDE,
then I also agree. At least, I've not heard of any. And I don't know of
any manufacturer that has backdoor hooks to allow the capabilities needed
to be implemented. (I'm not sure, but reasonably confident that most,
if not all, drives out there don't have the capability, even if a hacker had
ability to reprogram the firmware to do his bidding.)

However, there are TWO methods that will extract 'overwritten' info
from media. Both have strong points and caveats, and both involve
being able to access the drive other than through the 'user' interface.
Neither are 100% or secure, and neither can work through multiple
wipes. Or at least none that I know of can. But then...

It is NOT a myth.

The myth is telling people that it cannot be done.

Granted, it's beyond the abilities of almost any hacker I've heard of, but
it's NOT beyond the capabilities of manufacturers or certain organizations.

Risk to the consumer? Almost zilch.

But please don't come out with your blatant statement that it's a myth or
that it can't be done. You are just plain wrong, and either ignorant of
the technologies involved (I'll grant you that much) or are spouting a
'company line'. Which is it?

Mike

Nope that's a total myth.
No drive zero-wiped to government standards has even had any data
recovered
from it.

Actually, I'd suspect the 'government standard' is a myth. As far as I
know, I've
never been able to find ANY hard reference to a standard for wiping a drive,
other than 'second/third' or a 'friend of a friend said that' kind of thing.

Yes, I've heard the '7-wipes with alternate data' thing. But I've never
seen
it where it could be formally referenced. Just hearsay.

Mike Y wrote:

you will not be able to recover any data whatsoever on a wiped hard
drive, it can't be done, period!

John

And by the way, I do not work for any company that is in anyway involved
in the sale or development of anything to do with computer technology or
software.


Well, I do, and did. I've been involved with the 380 chip set way back, and
I do know a bit about how it and hard drives in general work. And while
I've
not personally done it, I AM aware of the technologies involved, the theory
behind the technologies, and the practice implementing those technologies.
Granted, I've not heard much about the techniques since drives moved into
the ZBR (a LOT changed when drives went that route) world with the high
speed transfers (compared to early MFM), but there's nothing in the
techniques or theory that would make it impossible other than that the
tools and techniques have to stay 'ahead of the game' the same way they
were then.

It's doable. Period!

It cannot be done! Period! It is a theory only and it has never been
proven! Not too long ago the US Department of Defense issued a tender
call for someone to provide methods to recover data from wiped drives
and no one stepped up to the plate to fill the tender request.

I invite you to contact all the data recovery experts and all the data
recovery companies out there and tell them that you have done a Secure
wipe on a drive and then ask them if they can recover your data. 99.98%
of them will outright tell you that they cannot recover the data on the
drive, they will tell you that they can't even recover the data if it
was simply overwritten once with other data, never mind secure wiping.
Go ahead search the net and email them all and find out for yourself!
Of the .02% remaining who tell you that they can .01% are lying and the
other .01% will tell you to expect to pay at least $100,000 to even
"try" to recover the data and they will make no guarantee of anything
other than you will end up $100,000 poorer!

The claims that data recovery can be made on wipe drives comes from Dr.
Gutmann's research where he has shown that using Magnetic Force
Microscopy he might be able to recover data from wiped drives. Even Dr.
Gutmann later stated that many were making Voodoo science of his
research and that some were making greatly exaggerated claims of
successful data recovery on wiped drives, Dr. Gutmann stated that the
claims were even more so exaggerated considering the size of today's
hard disks, his research was done on a different class of disks and when
disks were relatively small.

Using MFM or software that analyzes analog magnetic signals it is said
that data can be recovered from wiped drives but keep in mind that MFM
actually takes photographs of the bits where data is stored, quoting one
source:

"This pains taking process takes several months, and when it is finished
these pictures have to be stitched together.

Consider that a 20GB hard drive consists of 160, 000, 000, 000 bits.
Including overheads that could rise to around 300, 000, 000, 000 bits,
with each individual bit represented by a magnetic flux change. Since
each MFM picture displaying this flux change uses around 100 bytes, the
result is 40 Terabytes of data to be analyzed. Data recovery by this
means can cost 100, 000s of Dollars..."

And once again, there is no guarantee that the above procedure will
recover data. On today's hard disks of hundreds of GB such recovery
efforts would take thousands of man hours to gather and years to analize!

The plain and simple fact, as stated in one of the reference papers
below, is that: "Although such exotic methods of data recovery are
theoretically possible, and have even been discussed in the
peer-reviewed literature [11, 12], I have found no evidence of
commercially viable recoveries being performed with them. Furthermore,
I have seen no public demonstrations of any of these methods that show
the recovery of files or even user data – only images or raw encoded data."


John

J. Sawyer- MAGNETIC DATA RECOVERY - THE HIDDEN THREAT (PDF)
http://tinyurl.com/2mvkay

Recovering Unrecoverable Data - The Need for Drive-Independant Data
Recovery 527KB PDF.
Charles H. Sobey Published April 14, 2004.
http://www.actionfront.com/whitepaper/Drive-Independent Data Recovery
Ver14Alrs.pdf

Secure Deletion of Data from Magnetic and Solid-State Memory
Peter Gutmann
Department of Computer Science
http://www.cs.auckland.ac.nz/~pgut00...ecure_del.html

Overwitten data: Why even the Secret Service can't get it back
http://www.computerworld.com/blogs/node/5756

Is overwritten data really unrecoverable?
http://blogs.computerworld.com/node/5687

Can Intelligence Agencies Read Overwritten Data?
http://www.nber.org/sys-admin/overwr...a-guttman.html

Ontrack Eraser
http://www.ontrackdatarecovery.com/h...ck-eraser.aspx

Examining DoD-level secure erasure guidelines
http://searchsecurity.techtarget.com...273281,00.html

Secure Erase
http://cmrr.ucsd.edu/people/Hughes/C...eProtocols.pdf
http://cmrr.ucsd.edu/people/Hughes/D...onTutorial.pdf
http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml

John

you will not be able to recover any data whatsoever on a wiped hard
drive, it can't be done, period!

John

And by the way, I do not work for any company that is in anyway involved
in the sale or development of anything to do with computer technology or
software.

Well, I do, and did. I've been involved with the 380 chip set way back, and
I do know a bit about how it and hard drives in general work. And while
I've
not personally done it, I AM aware of the technologies involved, the theory
behind the technologies, and the practice implementing those technologies.
Granted, I've not heard much about the techniques since drives moved into
the ZBR (a LOT changed when drives went that route) world with the high
speed transfers (compared to early MFM), but there's nothing in the
techniques or theory that would make it impossible other than that the
tools and techniques have to stay 'ahead of the game' the same way they
were then.

It's doable. Period!

I'll give you one hint... Writing a 0 or a 1 DOESN'T totally erase what is
under it. Can you understand that? All writing a 0 or a 1 does is put
(actually,
'TRY' to put ) flux transitions down on the media at specific points. Or
try to.
Data already down on the media will influence where those transitions
actually
end up being detected on readback (digital), or distortions in the signal
(analog) ...

I'm through arguing with someone who obviously doesn't know what they are
talking about. You just cannot prove something doesn't exist or that
something
is impossible. You're putting yourself in the same reference frame as
people
who said manned piloted aircraft will never exceed the speed of sound. Or
that rockets just couldn't carry enough fuel in a 'step rocket'
(multi-stage)
to make it to the moon. In both cases, relatively simple technology
advances
led to the solution to the problem. You just can't understand that the
technology you see and touch is not the only technology that may exist.

Which pretty well tells us a lot about your level of expertise in this
field.

US Dept of Defense Standard 5220.22-M
http://www.qsgi.com/usdod_standard_dod_522022m.htm

Before posting about hearsay and myths that you heard you should do a
bit of research.

John

Ok, got me. Hmm, I'll bet that came well after... Well, I'll leave that
one
alone. But thank you for the reference.

What I was actually alluding to (and you failed to quote) was the off-touted
'7 times overwrite' often billed (by even the Norton Utilities WipeDisk at
one point) as an NSA standard. That I could never find a hard reference
to no matter how hard I looked.

I really do thank you for that link.

But you actually make my case. That you post something the government
is actually concerned about (because they CAN do it).

From a practical matter, data recovery is probably possible but not solid
at one overwrite, 'iffy' with two, and probably secure at three. And these
are with methods of mathematical analysis in 1993 or so that I'm sure
by now have come a long way. But that's just my gut call. Since drives
went ZBR how the data would interact to an overwrite may be radically
different than before. Who knows, it may be easier!

I certainly would expect that writing pseudorandom, or even identical, bytes
to each and every sector on the disk would make it nigh impossible to
recover anything, - IF that laboriously slow procedure was invoked. How it
could possibly be otherwise makes little sense to me - unless we operate
under the assumption that the electromagnetic writes are somewhat incomplete
(that is, the magnetic domains on the disk are not fully reversed (or
realigned) completely, but still have some very small residual leftover
effects (i.e. retentivity) from a previous write operation). (I'm an EE,
but I'm just making some basic assumptions here).

John John wrote:
Mike Y wrote:

you will not be able to recover any data whatsoever on a wiped hard
drive, it can't be done, period!

John

And by the way, I do not work for any company that is in anyway involved
in the sale or development of anything to do with computer technology or
software.


Well, I do, and did. I've been involved with the 380 chip set way back,
and
I do know a bit about how it and hard drives in general work. And while
I've
not personally done it, I AM aware of the technologies involved, the
theory
behind the technologies, and the practice implementing those
technologies.
Granted, I've not heard much about the techniques since drives moved into
the ZBR (a LOT changed when drives went that route) world with the high
speed transfers (compared to early MFM), but there's nothing in the
techniques or theory that would make it impossible other than that the
tools and techniques have to stay 'ahead of the game' the same way they
were then.

It's doable. Period!

It cannot be done! Period! It is a theory only and it has never been
proven! Not too long ago the US Department of Defense issued a tender
call for someone to provide methods to recover data from wiped drives
and no one stepped up to the plate to fill the tender request.

snip

"John John" wrote in message
...
Mike Y wrote:

Nope that's a total myth.
No drive zero-wiped to government standards has even had any data

recovered

from it.


Actually, I'd suspect the 'government standard' is a myth. As far as I
know, I've
never been able to find ANY hard reference to a standard for wiping a
drive,
other than 'second/third' or a 'friend of a friend said that' kind of
thing.

Which pretty well tells us a lot about your level of expertise in this
field.

US Dept of Defense Standard 5220.22-M
http://www.qsgi.com/usdod_standard_dod_522022m.htm

Before posting about hearsay and myths that you heard you should do a
bit of research.

John

Found something else on that link. In a blurb about software they sell.

"The software has the flexibility to overwrite a hard drive up to 99 times.
Each additional overwrite further minimizes the possibility of recovering
any data."

Seems pretty obvious to me that they are concerned about someone reading
data after a single overwrite...

Granted, they sell the software so it means they are not neutral, but
still...

I'm done with this. Again, thanks for the link.

Mike

"Jim Madsen" wrote in message
...
My daughter has an old Gateway computer running Windows 98. She says no
one wants it because it is slow and obsolete and she wants to turn it into
the local recycling place.

She is worried about (personal) data on the hard drive. I wonder if
reformatting the HD will destroy all the data? My old W95 computer, I
took the HD out and smashed it with a sledge hammer, but she doesn't want
to do that.

She took it to a computer store, and they offered to "hose" the HD and
dispose of the computer for $50.00.

Any suggestions?

Jim

Its my understanding regarding using format.com that:

A quick format simply uses the current file allocation table, indicating
lack of file data in the previously written file allocation table. Does not
verify the data locations as usable.

A format (full) removes/wipes the current file allocation table, verifies
the usable writing area for data file storage, updates that for writing new
file allocation table, then, writes the new file allocation table.

In either case, the file data still exists. And, easily recoverable with
most current data recovery software.

As stated in another reply, zero-write utilities, for the most part, are
suitable for most purposes of preventing the locating of prior written
personal data. Forensic tools can still find such data though. These rely
on the latency of the magnetic field of each bit that may have existed due
to prior writes created by prior use.

Regarding unformat. Was last available in dos 6.22. Its purpose was to
revert to the prior file allocation table. One cannot write files in the
interim and expect full file data access. An immediate unformat is expected
after realizing formatting was a mistake on the user's part. FAT32 did not
exist in the time frame of dos 6.22.
--
Dave

Lil' Dave wrote:

As stated in another reply, zero-write utilities, for the most part, are
suitable for most purposes of preventing the locating of prior written
personal data. Forensic tools can still find such data though. These rely
on the latency of the magnetic field of each bit that may have existed due
to prior writes created by prior use.

FUD! There are no forensic tools available that can recover data on
securely wiped drives. If you think such tools exist please
substantiate your claim and post links to such tools or other verifiable
information.

John