destorying the hard drive

[MEB]

Re: destorying the hard drive

I'll just make one comment in this discussion.

I would be extremely careful when making an FINAL statement on what can or
can not be done on supposedly securely wiped drives or any other claimed
event or finding.

Consider that "the world is flat", "the sun revolves around the earth",
"man can not fly", "ships will fall of the end off the ocean and men eaten
by monsters", "computers can never replace man because they must be
programmed by men", "the Internet is secure when using VPN connections",
"PGP can not be broken", "this connection is secure", and thousands of other
fallacies that were supposedly PROVEN as true, then later proven as false.

--
MEB
http://peoplescounsel.orgfree.com
--
_________

 

[Gary S. Terhune]

Re: destorying the hard drive

Bottom line: I will continue to assume that the US government and others
have the ability to retrieve data from a zero-filled drive (regardless of
how many wipes). As good as your data sounds, as good as your due diligence
seems to have been, I don't actually know you. Even if I did, it would make
no difference. Nothing you offer *proves* that it can't be done, and your
contention that it's never been done is, again, something I would have to
take on faith.

Now, ask me if I give much of a damn what the government can read from my
hard drive. They already know MUCH more than that about me. And about you,
too, and everyone else in this joint with their silly fears, aliases, etc.
If I have something to hide from the government or other major power, adding
a degausser to my toolkit and using it will be a minor issue. Your own
claims would be merely academic irrlevancies.

--
Gary S. Terhune
MS-MVP Shell/User
www.grystmill.com

"John John" <audetweld@nbnet.nb.ca> wrote in message
news:%23I7lHidjIHA.3940@TK2MSFTNGP05.phx.gbl...
>I have had private email conversations with Peter Gutmann on this subject
>and he has told me that he was never able to recover data on a wiped drive,
>all he could ever do was show presence of previous data, he could not tell
>what the previous data was. His method was offered as a theoretical method
>of data recovery, he used it to reinforce the need for secure deletion
>methods. Read the Epilogue in his paper. In my conversation with him I
>asked him if he knew if anyone had ever used his method to recover data on
>a wiped drive, to which he replied that he knew of none who had. He knew
>of one person working for a hard drive manufacturer who had done research
>on the matter but to his knowledge the research led nowhere. Dr. Gutmann
>would not give me the name or address of this researcher because he (the
>researcher) was doing this research without his employer's knowledge or
>explicit consent, Peter did not want to put this person in an
>"uncomfortable" position.
>
> John
>
> Gary S. Terhune wrote:
>> You now have a case of battling scientific papers, and you're going to
>> have to do a lot more than just insist that you're guy's right. Or
>> rather, you should give it up until Gutmann himself fess's up. From where
>> I sit, the more you yell, the lower your credibility goes. Provide your
>> references to the best of your ability and then let them speak for
>> themselves.
>>
>

 

[John John]

Re: destorying the hard drive

What about the bogey man? Or the Abominable Snowman? Are they real?
Many speak of them but no one has ever been able to prove their
existence. Much the same as data recovery on securely wiped drives,
many speak of it but no one has yet shown proof of it.

John

MEB wrote:

> I'll just make one comment in this discussion.
>
> I would be extremely careful when making an FINAL statement on what can or
> can not be done on supposedly securely wiped drives or any other claimed
> event or finding.
>
> Consider that "the world is flat", "the sun revolves around the earth",
> "man can not fly", "ships will fall of the end off the ocean and men eaten
> by monsters", "computers can never replace man because they must be
> programmed by men", "the Internet is secure when using VPN connections",
> "PGP can not be broken", "this connection is secure", and thousands of other
> fallacies that were supposedly PROVEN as true, then later proven as false.
>

 

[Mike Y]

Re: destorying the hard drive


"thanatoid" <waiting@the.exit.invalid> wrote in message
news:Xns9A6B864CD5D6Fthanexit@66.250.146.158...

> Hmm... A /little/ beyond my knowledge of physics and
> electronics, but I /think/ I kind of get it. So in "stupid"
> terminology, there is a mess of data (I'll leave aside the a/d
> distinction since it kind of threw me) in each sector, some of
> it may be weak, some may be stronger, but the latest write will
> (hopefully) be the strongest and easiest to read. With time it
> all gets messier, but the latest signal remains the strongest,
> which is why even though there's noise, it never reaches the
> point where the drive would be unreadable. The latest writes,
> anyway. I would seem the garbage underneath - certainly the
> older writes - is for all intents and purposes garbled beyond
> any recoverability.
>
> Did I sort of understand you?
>

Pretty darn close, in a logic sense. But it's a bit more complicated than
that. The 'garbage underneath' as you put it, in a digital sense,
influences slightly the timing of the flux transitions. In a digital data
stream, as long as the timing is 'in the window', then it doesn't matter.
It's like saying 1200 baud vs 1199 baud. Could you tell? As long
as each bit by the end of the word is still in the timing cell, so what.
But if you were to carefully analyze the 1199 baud data stream, you
could see that the 'bits' were not aligning quite right. Heck, you could
hide a secret (low speed) message inside a serial data stream by
adjusting the speed up and down but still within valid timing constraints
of the 'official' speed.

Anyway, that's one aspect of it. The other is residual analog data. While
the data is digital, the magnetic field imprinted on the media is analog.
Again, as long as any aberrations of the field is not causing the digital
data to go outside of the 'windows' it should be in for correct digital
data,
it doesn't matter.

And remember, disk drive electronics have evolved over the years to
get more and more robust with regard to pulling out the last recorded
data and ignoring everything else that is there.

Hmm, just think back to HiFi tape days... I know, it's not directly
applicable to this, but from a purely analog point of view, did you
ever make a tape, then tape over and (on some equipment) if you
cranked up things hear a faint remnant? Usually that was just due to
cheap equipment that didn't fully erase, but in a 'master studio' if the
tape wasn't 'brand new' out of the box, it just wasn't used to master.
Sure, equipment evolved and it quickly became a non-issue. But
that was analog in an analog world. Residual data in magnetic drives
wasn't an issue, the issue was just making sure the latest data was
the data it extracted. Yeah, they did improve the recording technology
a bit, but almost all the 'improvements' were in the reading and
data separation areas.

 

[Mike Y]

Re: destorying the hard drive


"thanatoid" <waiting@the.exit.invalid> wrote in message
news:Xns9A6B8652E670Dthanexit@66.250.146.158...
>
> Do you remember when people started using VHS tapes JUST to
> record music - in the Hi-Fi mode - since, even though analog,
> its quality rivaled digital?

I had one of the early HiFi VHS decks, and never really liked it. There
was Stereo VHS also, but that was different, I don't remember exactly
how. I was actually a Beta guy, having one of the early SL-7200
machines. (Beta I only, 90 minutes with the 750 tape. There was a
longer tape, but some machines would eat it on a regular basis.) Then
went SL-8200 for 2-speed. Finally ended up with a Beta-HiFi deck.
It actually recorded the audio on 4 subcarriers, so the head would
switch 2 and 2 as it spun without dropouts and collisions. The deck even
had an 'audio' switch on it that did something to some of the other
subcarriers
(luminence if I remember right) that supposedly gave it even better
audio quality when used just for audio. It supported Beta II and III,
but not Beta I. Oh well.

> (Straying further off-topic, I have always considered the
> Philips audio cassette as one of the great inventions of the
> last century. If they had ONLY included a 50 or 60 Hz "sync"
> (for 100% speed accuracy) track like VTR's do, they would have a
> format that IMO would still be viable today. In fact, it would
> not entirely surprise me if, frustrated by DMCA, DRM, etc.
> someone someday tried to bring back the analog cassette -
> hopefully WITH the sync track feature.)

The Philips cassette was definitely neat. I heard that the license was
such that all future cassettes had to be back compatible. That's why
they laid the stereo tracks adjacent so they would play on a mono
deck, and mono tapes would play on the stereo. Sorta killed it for
4-channel though. For a short time there were '2-speed' cassette
decks. Nice. But they disappeared pretty quickly from the market.
I don't know how they handled the license restrictions...

 

[Lil' Dave]

Re: destorying the hard drive

"Gary S. Terhune" <none> wrote in message
news:OkgVhwdjIHA.2276@TK2MSFTNGP05.phx.gbl...
> Bottom line: I will continue to assume that the US government and others
> have the ability to retrieve data from a zero-filled drive (regardless of
> how many wipes). As good as your data sounds, as good as your due
> diligence seems to have been, I don't actually know you. Even if I did, it
> would make no difference. Nothing you offer *proves* that it can't be
> done, and your contention that it's never been done is, again, something I
> would have to take on faith.
>
> Now, ask me if I give much of a damn what the government can read from my
> hard drive. They already know MUCH more than that about me. And about you,
> too, and everyone else in this joint with their silly fears, aliases, etc.
> If I have something to hide from the government or other major power,
> adding a degausser to my toolkit and using it will be a minor issue. Your
> own claims would be merely academic irrlevancies.
>
> --
> Gary S. Terhune
> MS-MVP Shell/User
> www.grystmill.com
>
> "John John" <audetweld@nbnet.nb.ca> wrote in message
> news:%23I7lHidjIHA.3940@TK2MSFTNGP05.phx.gbl...
>>I have had private email conversations with Peter Gutmann on this subject
>>and he has told me that he was never able to recover data on a wiped
>>drive, all he could ever do was show presence of previous data, he could
>>not tell what the previous data was. His method was offered as a
>>theoretical method of data recovery, he used it to reinforce the need for
>>secure deletion methods. Read the Epilogue in his paper. In my
>>conversation with him I asked him if he knew if anyone had ever used his
>>method to recover data on a wiped drive, to which he replied that he knew
>>of none who had. He knew of one person working for a hard drive
>>manufacturer who had done research on the matter but to his knowledge the
>>research led nowhere. Dr. Gutmann would not give me the name or address
>>of this researcher because he (the researcher) was doing this research
>>without his employer's knowledge or explicit consent, Peter did not want
>>to put this person in an "uncomfortable" position.
>>
>> John
>>
>> Gary S. Terhune wrote:
>>> You now have a case of battling scientific papers, and you're going to
>>> have to do a lot more than just insist that you're guy's right. Or
>>> rather, you should give it up until Gutmann himself fess's up. From
>>> where I sit, the more you yell, the lower your credibility goes. Provide
>>> your references to the best of your ability and then let them speak for
>>> themselves.
>>>
>>
>

If anyone intends to hide anything from an entity with the resources of the
U.S. government, a PC hard drive is the last place to hide same.

--
Dave

How about a tax to support any military conflict/police action over 3 months
old?

An actual war, we can do what's been done in the past.

 

[Mike Y]

Re: destorying the hard drive


"thanatoid" <waiting@the.exit.invalid> wrote in message
news:Xns9A6BECCAB8555thanexit@66.250.146.158...

> >> (Straying further off-topic, I have always considered the
> >> Philips audio cassette as one of the great inventions of
> >> the last century. If they had ONLY included a 50 or 60 Hz
> >> "sync" (for 100% speed accuracy) track like VTR's do, they
> >> would have a format that IMO would still be viable today.
> >> In fact, it would not entirely surprise me if, frustrated
> >> by DMCA, DRM, etc. someone someday tried to bring back the
> >> analog cassette - hopefully WITH the sync track feature.)
> >
> > The Philips cassette was definitely neat. I heard that the
> > license was such that all future cassettes had to be back
> > compatible. That's why they laid the stereo tracks
> > adjacent so they would play on a mono deck, and mono tapes
> > would play on the stereo. Sorta killed it for 4-channel
> > though. For a short time there were '2-speed' cassette
> > decks. Nice. But they disappeared pretty quickly from the
> > market. I don't know how they handled the license
> > restrictions...
>
> Yes, the double speed must have produced excellent sound. And
> even at 1 7/8, Nakamichi had some very impressive technology
> enhancements and the tapes sounded great - when the decks
> actually worked. An audio repair technician coworker of mine
> used to say "Nakamichi - great, as long as you never press the
> power switch!" (he used to say the same about B&O).
>
> Then there were the weirdo vari-speed portable cassette decks
> used for business and as dictaphones... Ah, the memories... ;-)
>
> I think the restrictions of the Philips original were quite
> relaxed after a while - I /believe/ the original even specified
> 30, 60 and 90 mins. as the only OK lengths. Not to mention
> chrome, metal, super-avilyn (never DID find out what THAT was,
> but the BEST sounding cassettes of the 500 or so I still have
> were the TDK AD's, not chrome or SA, but "enhanced standard").
>
> Did you ever see the weirdness that was the attempt in the mid
> 90's to make a digital cassette format physically based on the
> Philips specs, but which would play back the regular AND record
> (and play, obviously) digital? Sometimes you really wonder what
> people are thinking of. I wonder if even 200 of those decks were
> ever sold worldwide.
>
> Nice chatting. Cheers.
>
I remember some cassette deck that had helical scan, and the first thought
in my mind was how to handle condensation in a car. But I don't
think that was standard cassette. Hey, if it weren't for the clocks on
home VCRs, there's still be 'DEW' warnings. My first two Beta units
had external clocks (mechanical) that turned the thing on and off. If
the DEW light was on, you had to wait to use it. Once clocks were
in VCRs, then they stayed warm enough to not be a problem, since
power would never be turned off.

B&O... Great sound, but... My girlfriend bought me a B&O MMC4000
cartridge for my system for Christmas one year. It was utterly
fantastic. But about 3 years later got intermittent on one channel.

I had a friend with a Nak deck. Nice. But I picked up an Hitachi that
sounded better. The Nak was quieter. In fact, was the quietest tape
unit I ever heard (or didn't hear). But my Hitachi had front panel
bias controls, had front panel level tracking, and internal generators
so you could set record/playback and even bias for Dolby levels.
It was a 3-head unit, and the -3db and -20db curves NEVER intersected
in the audio band! Unfortunately it didn't do metal tape. I never tried
the TDK AD but did try the SA. Not bad, but I ended up with
Maxell UD-XL Type II and bought that in 'case lots' so I only had
to set the tape up once (although I always did it every time, it was
so easy).

 

[Franc Zabkar]

Re: destorying the hard drive

On 24 Mar 2008 19:09:09 GMT, thanatoid <waiting@the.exit.invalid> put
finger to keyboard and composed:

>Franc Zabkar <fzabkar@iinternode.on.net> wrote in
>news:rngeu3dsf5jflvcius8rpdq1g9r3al3ipk@4ax.com:

>>>This idea - as *fact* - was presented in a thread with the
>>>same subject (I wonder just HOW many of those there have
>>>been by now) by someone a few years ago. He claimed a
>>>"residue" of whatever is written to a HD /REMAINS/ even if
>>>you write over it a bunch of times - something like: new
>>>drive, zero-formatted - 100% magnetic signal retention,
>>>second write in the same sector - 95%, third 90%, etc. I
>>>pointed out that simple logic would dictate that if
>>>anything like this was true, all drives would fail within a
>>>few weeks of being installed. There was no reply.
>>
>> Yeah, that makes sense.
>
>What HE said or what I said? Having read the last few posts, I
>now think he was correct (although perhaps not expressing
>himself as well as he could have) but that (consistently with my
>regrettable black-and-white way of looking at everything) I
>interpreted his statements not unlike using a sledgehammer with
>a push-pin.

Maybe I didn't understand you or the other person correctly. FWIW this
is how I would look at it.

Let's assume we have three recordings, A, B, and C, where A is the
first and C is the latest. Let's also assume that we are starting with
a blank magnetic medium and that each recording is only 90% efficient,
ie 10% of the previous signal is not erased.

After recording # A, the recorded signal consists of 100% A.

After recording # B, the recorded signal consists of 90% B and 10% A.

After recording # C, the recorded signal consists of 90% C, 9% B and
1 % A.

The above result is a lot different than your example. AFAICT, in your
example the noise component would grow every time you wrote new data
to the same sector because you would accumulate contributions from all
past writes.

>Do you remember when people started using VHS tapes JUST to
>record music - in the Hi-Fi mode - since, even though analog,
>its quality rivaled digital?

Yes, that was quite common. IIRC, the frequency response was better
than 20Hz - 20kHz. I also remember VHS tape and standard analogue VHS
VCRs being used as computer backup for office systems such as Corvus
during the 1980s.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Franc Zabkar]

Re: destorying the hard drive

On Mon, 24 Mar 2008 19:25:51 -0500, "Mike Y" <joe@user.com> put finger
to keyboard and composed:

>Hmm, just think back to HiFi tape days... I know, it's not directly
>applicable to this, but from a purely analog point of view, did you
>ever make a tape, then tape over and (on some equipment) if you
>cranked up things hear a faint remnant? Usually that was just due to
>cheap equipment that didn't fully erase, but in a 'master studio' if the
>tape wasn't 'brand new' out of the box, it just wasn't used to master.
>Sure, equipment evolved and it quickly became a non-issue. But
>that was analog in an analog world. Residual data in magnetic drives
>wasn't an issue, the issue was just making sure the latest data was
>the data it extracted. Yeah, they did improve the recording technology
>a bit, but almost all the 'improvements' were in the reading and
>data separation areas.

As you have already said, in the analogue domain you have degrees of
magnetisation whereas in the digital domain you have flux reversals. I
notice that analogue recording devices such as VCRs and compact audio
cassette recorders have an erase head before the read/write head. When
an erase circuit fails in a VCR, a ghost of the previous audio signal
remains after new audio information is recorded. IIRC, such a failure
does not significantly impact on the video signal. You should be able
to see this for yourself if you hold the erase head away from the tape
path during recording. I think the bias oscillator (via the
record/play head) tries its best to randomise the magnetic domains but
there is always a small audible remnant of the previous recording.
Therefore the erase head is necessary to completely wipe the tape. In
the digital domain, however, there is no erase head, only a read/write
head. AIUI, a separate erase head is not required because the
magnetisation is always "full on", ie either positive or negative.
Zeros and ones are encoded as flux transitions, not flux levels, so
there is no portion of the medium that is not fully magnetised. Since
the circuitry is designed to detect these flux reversals, then it does
not discriminate between a 100% one bit or a "noisy" 70% one bit. Both
are seen as a logic 1.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Mike Y]

Re: destorying the hard drive


"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message
newsp5ju3hvdtjsic3icon7vnoncaqht3o3on@4ax.com...
> On Mon, 24 Mar 2008 19:25:51 -0500, "Mike Y" <joe@user.com> put finger
> to keyboard and composed:
>
> >Hmm, just think back to HiFi tape days... I know, it's not directly
> >applicable to this, but from a purely analog point of view, did you
> >ever make a tape, then tape over and (on some equipment) if you
> >cranked up things hear a faint remnant? Usually that was just due to
> >cheap equipment that didn't fully erase, but in a 'master studio' if the
> >tape wasn't 'brand new' out of the box, it just wasn't used to master.
> >Sure, equipment evolved and it quickly became a non-issue. But
> >that was analog in an analog world. Residual data in magnetic drives
> >wasn't an issue, the issue was just making sure the latest data was
> >the data it extracted. Yeah, they did improve the recording technology
> >a bit, but almost all the 'improvements' were in the reading and
> >data separation areas.
>
> As you have already said, in the analogue domain you have degrees of
> magnetisation whereas in the digital domain you have flux reversals. I
> notice that analogue recording devices such as VCRs and compact audio
> cassette recorders have an erase head before the read/write head. When
> an erase circuit fails in a VCR, a ghost of the previous audio signal
> remains after new audio information is recorded. IIRC, such a failure
> does not significantly impact on the video signal. You should be able
> to see this for yourself if you hold the erase head away from the tape
> path during recording. I think the bias oscillator (via the
> record/play head) tries its best to randomise the magnetic domains but
> there is always a small audible remnant of the previous recording.
> Therefore the erase head is necessary to completely wipe the tape. In
> the digital domain, however, there is no erase head, only a read/write
> head. AIUI, a separate erase head is not required because the
> magnetisation is always "full on", ie either positive or negative.
> Zeros and ones are encoded as flux transitions, not flux levels, so
> there is no portion of the medium that is not fully magnetised. Since
> the circuitry is designed to detect these flux reversals, then it does
> not discriminate between a 100% one bit or a "noisy" 70% one bit. Both
> are seen as a logic 1.
>
> - Franc Zabkar

You hit it pretty square on the head. Mostly. In writing, the current is
not 'full on'. It's balanced with where the head is positioned on the
media.
Early drives had reduced write current controls that the controller was
responsible for triggering when the head was positioned halfway towards
the center of the spinning media. That means there were only two levels,
and in each 'zone' there would be areas where the current was reduced
under optimum. And always remember, the circuitry was designed to
give 'reliable readback' of data, it was NOT necessarily designed to
mandate magnetic saturation at all points on the media. If two much
current caused distortions and errors, and too little meant reduced S/N
ratios that could be compensated for with PLL recovery schemes, then
you can bet the MOST the current would ever be set for was before it
saturated and caused data errors and let the data separators do their
job on read.

And your statement about the 100% or 70% both being seen as a logic
one is dead on. Well, in FM recording. In MFM and later formats, the
bits are NOT 1 or 0, they are time marks, and the time marks determine
0 or 1. But the same idea applies.

Anyway, drives went from FM to MFM to RLL to ESDI (5 different
ESDI speeds if I remember right) to finally IDE, where the drive and
the controller are one. Why separate them? Once the drive and
controller are one, does it matter what's inside the bubble? Nowadays,
most drives lie worse than the last car salesman I DIDN'T deal with.
But it doesn't matter, all that matters to the user is the 'data packets'
that come out the IDE bus (IF it's an IDE drive, the SATA interface
if it's a SATA drive, or SCSI if it's SCSI) are correct and contain
the information desired. With the new drives the media is now
referred to, if I remember right, ZBR, or something like Zone Bit
Recorded. Basically it means the controller in the drive breaks the
media up into 'Zones' and changes things as it feels necessary. That
is, the number of sectors on a track changes, depending on the
velocity under the head (near the rim is faster) and even the RATE
of flux changes is adjusted for best performance and capacity.
The end result is that with modern drives, the user at the 'interface
point' to a drive is even FURTHER isolated from what goes on in
the sealed box call a hard disk drive, and reading anything from the
drive other than what the drive is designed to read and report would
be quite impossible.

 

[Jeff Richards]

Re: destorying the hard drive

The difference being that, even though the ghost is there and visible,
there's no way to separate the earlier image from the later image. It's one
signal from a mixed source. The human brain can identify the ghost as a
ghost, but that's a trick technology hasn't yet mastered.

With a digital format it's possible, in theory, to analyse the analogue
signal from the drive read head and to identify flux transitions from
previous recordings. Any existing flux transition on the disk surface will
affect the way that the later transition gets recorded. The idea is that
with modern high speed DSP the analogue signal can reveal the artefacts in
a flux transition that reflect the previous version of the digital data.
Combined with pattern matching technology and some guesswork, the earlier
version flux transitions could be re-created from those remnants, and the
original digital signal reconstructed.

Whether anyone has actually done it is doubtful, but the paranoid amongst us
will claim that the lack of any evidence simply proves that the CIA can do
it, and has managed to keep it secret.
--
Jeff Richards
MS MVP (Windows - Shell/User)
"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message
newsp5ju3hvdtjsic3icon7vnoncaqht3o3on@4ax.com...
> On Mon, 24 Mar 2008 19:25:51 -0500, "Mike Y" <joe@user.com> put finger
> to keyboard and composed:
>
>snip <
> As you have already said, in the analogue domain you have degrees of
> magnetisation whereas in the digital domain you have flux reversals. I
> notice that analogue recording devices such as VCRs and compact audio
> cassette recorders have an erase head before the read/write head. When
> an erase circuit fails in a VCR, a ghost of the previous audio signal
> remains after new audio information is recorded. IIRC, such a failure
> does not significantly impact on the video signal. You should be able
> to see this for yourself if you hold the erase head away from the tape
> path during recording. I think the bias oscillator (via the
> record/play head) tries its best to randomise the magnetic domains but
> there is always a small audible remnant of the previous recording.
> Therefore the erase head is necessary to completely wipe the tape. In
> the digital domain, however, there is no erase head, only a read/write
> head. AIUI, a separate erase head is not required because the
> magnetisation is always "full on", ie either positive or negative.
> Zeros and ones are encoded as flux transitions, not flux levels, so
> there is no portion of the medium that is not fully magnetised. Since
> the circuitry is designed to detect these flux reversals, then it does
> not discriminate between a 100% one bit or a "noisy" 70% one bit. Both
> are seen as a logic 1.
>
> - Franc Zabkar
> --
> Please remove one 'i' from my address when replying by email.

 

[Jeff Richards]

Re: destorying the hard drive

A lack of proof that it exists is not the same as proving that it doesn't -
they are two very different results.

No-one has proved that the abominable snowman exists, but no-one has shown
that it doesn't.

Proving that something doesn't exist or cannot happen is difficult. Some
scientists will say it is impossible.
--
Jeff Richards
MS MVP (Windows - Shell/User)
"John John" <audetweld@nbnet.nb.ca> wrote in message
news:eWoXxQejIHA.4244@TK2MSFTNGP06.phx.gbl...
> What about the bogey man? Or the Abominable Snowman? Are they real? Many
> speak of them but no one has ever been able to prove their existence.
> Much the same as data recovery on securely wiped drives, many speak of it
> but no one has yet shown proof of it.
>
> John
>
> MEB wrote:
>
>> I'll just make one comment in this discussion.
>>
>> I would be extremely careful when making an FINAL statement on what can
>> or
>> can not be done on supposedly securely wiped drives or any other claimed
>> event or finding.
>>
>> Consider that "the world is flat", "the sun revolves around the earth",
>> "man can not fly", "ships will fall of the end off the ocean and men
>> eaten
>> by monsters", "computers can never replace man because they must be
>> programmed by men", "the Internet is secure when using VPN connections",
>> "PGP can not be broken", "this connection is secure", and thousands of
>> other
>> fallacies that were supposedly PROVEN as true, then later proven as
>> false.
>>
>