Question about old "wipe" thread

Drutten · 09-05-2003, 09:01 AM

Quote:

Originally posted by no-one
to delete a file to where it can't be recovered you have to delete and write over the data 8 times, well, if you've got something that important anyway, your probably got a sniper aiming at your head as we speak.

This can't possible be right (and why 8 times)? Once should be enough?!

**Hammer** · 09-05-2003, 12:57 PM

I use this:
http://www.east-tec.com/eraser/index.htm

There's probably an FAQ explaining why data needs to be overwritten so many times, try a search (or look on the link I've given).

RobR · 09-05-2003, 01:06 PM

Try this.

Waldo2k2 · 09-05-2003, 01:10 PM

my theory is that all "sensitive" material should be written to cd....those can melt if needed.

confuted · 09-05-2003, 02:03 PM

Quote:

Originally posted by Waldo2k2
my theory is that all "sensitive" material should be written to cd....those can melt if needed.

Yeah, if you do exactly what #1 on this page tells you not to you can melt a CD rather easily with a cigarette lighter. A three inch tall flame and an AOL CD quickly yield a 3 inch tall flame and an AOL CD which is quite ruined.

I would, of course, know nothing about this.

Drutten · 09-05-2003, 02:04 PM

Well I was more interested in knowing how it's possible to reconstruct the orientation of the bits physically on the disk (should not be?)? If it's due to a flaw in the program performing the wiping, then the error ought to repeat it self during wipe(n) (n=2,3,4...)? An other question would be if this is merely done to make consumers feel safer

?

RobR · 09-05-2003, 02:13 PM

Putting a CD top side down on a cement floor & sliding it with your foot is pretty effective too. You end up with a clear plastic disk. Breaking them is not recommended. I did it once and was picking bits off my floor for 3 days afterwards!

Waldo2k2 · 09-05-2003, 02:24 PM

The reason I suggested Cd melting is because of physics.
Physics are what allow people to recover data from hard drives that have been in fires. Hd's rely on magnetism, magnetism has predictable properties. No matter how many times you write over a spot (afaik) there are still magnetic traces of whats been there....that may not be helpful with 0's and 1's alone, but if a cop can begin to peice together old file tables, your ass is grass.

A Cd melting also adheres to the laws of physics, but the rules aren't as strict. The plastic goes everywhere and changes chemical composition due to heat, etc. It's impossible to recover data from a melted cd (with today's, and im sure, the next hundred year's technology) because there are so so so many different variables in place....that, and a cd isn't either pos or neg like an hd. It's light, dark, gray, scratched, etc. It's the same as writing a note on a peice of paper and burning it, it's the type of data you interpret visually (optically with a laser for cds). Once you burn the paper, there's no way of looking at the ashes and reconstructing the image.

Drutten · 09-05-2003, 02:42 PM

I'm about to take my MS deg. in eng. so I have some basic knowledge in physics. But if your drive isn't brand new then the noise from past writings (regard one bit as an area where maybe not the entire area is affected by the wipe-write...thus traces left in the outer part of that area) should be pretty random, and if you wipe with random data how can that be interpreted to something useful?

**Thantos** · 09-05-2003, 02:47 PM

Wouldn't writting ones to all the sectors before writing zeros be effective in covering up the orginal data?

Waldo2k2 · 09-05-2003, 03:03 PM

become a hacker, do that to your drive, and see if they can't still convict you.

Drutten · 09-05-2003, 03:24 PM

I'm not trying to wipe anything

just curious why all these repetitions. It takes quite a while wiping the empty space just once on a drive. Does it really make a real difference

?

confuted · 09-05-2003, 04:32 PM

If you REALLY need to destroy some data, I would highly advocate a physical destruction rather than hoping some program can do it for you. If you open the hard drive, you could shatter the platters with a hammer. They're rather brittle.

Or I suppose that if you have access to a very powerful electromagnet, that could do the trick.

Drutten · 09-05-2003, 04:50 PM

Quote:

Originally posted by confuted
If you open the hard drive, you could shatter the platters with a hammer. They're rather brittle.

It's the same effect as breaking a CD-R disc...pieces all over the place

. But it's kind of unrefined... not a choice for most peoples/organizations

! But that wasn't an answer to my question

!

Waldo2k2 · 09-05-2003, 06:03 PM

The company (or individual) who wrote the software wants the unwary user to feel like the program is actually going to work. And it will in nearly all common day needs...but don't trust it when the CIA comes busting down your door...not that they will, but that's what we're all getting at. There's really no point in writing over it that manytimes, if someone REALLY wants the info on your drive, they can get it. Such is the world of electronics.

09-05-2003, 12:57 PM	#2
Hammer End Of Line Join Date: Apr 2002 Posts: 6,240	I use this: http://www.east-tec.com/eraser/index.htm There's probably an FAQ explaining why data needs to be overwritten so many times, try a search (or look on the link I've given). __________________ When all else fails, read the instructions. If you're posting code, use code tags: [code] /* insert code here */ [/code]
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09-05-2003, 01:06 PM	#3
RobR www.entropysink.com Join Date: Feb 2002 Posts: 603	Try this. __________________ Visit entropysink.com - It's what your PC is made for!
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09-05-2003, 01:10 PM	#4
Waldo2k2 PC Fixer-Upper Join Date: May 2002 Posts: 2,001	my theory is that all "sensitive" material should be written to cd....those can melt if needed. __________________ PHP and XML Let's talk about SAX
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09-05-2003, 02:04 PM	#6
Drutten Registered User Join Date: Aug 2003 Posts: 7	Well I was more interested in knowing how it's possible to reconstruct the orientation of the bits physically on the disk (should not be?)? If it's due to a flaw in the program performing the wiping, then the error ought to repeat it self during wipe(n) (n=2,3,4...)? An other question would be if this is merely done to make consumers feel safer ? Last edited by Drutten; 09-05-2003 at 02:07 PM.
Drutten is offline

09-05-2003, 02:13 PM	#7
RobR www.entropysink.com Join Date: Feb 2002 Posts: 603	Putting a CD top side down on a cement floor & sliding it with your foot is pretty effective too. You end up with a clear plastic disk. Breaking them is not recommended. I did it once and was picking bits off my floor for 3 days afterwards! __________________ Visit entropysink.com - It's what your PC is made for!
RobR is offline

09-05-2003, 02:24 PM	#8
Waldo2k2 PC Fixer-Upper Join Date: May 2002 Posts: 2,001	The reason I suggested Cd melting is because of physics. Physics are what allow people to recover data from hard drives that have been in fires. Hd's rely on magnetism, magnetism has predictable properties. No matter how many times you write over a spot (afaik) there are still magnetic traces of whats been there....that may not be helpful with 0's and 1's alone, but if a cop can begin to peice together old file tables, your ass is grass. A Cd melting also adheres to the laws of physics, but the rules aren't as strict. The plastic goes everywhere and changes chemical composition due to heat, etc. It's impossible to recover data from a melted cd (with today's, and im sure, the next hundred year's technology) because there are so so so many different variables in place....that, and a cd isn't either pos or neg like an hd. It's light, dark, gray, scratched, etc. It's the same as writing a note on a peice of paper and burning it, it's the type of data you interpret visually (optically with a laser for cds). Once you burn the paper, there's no way of looking at the ashes and reconstructing the image. __________________ PHP and XML Let's talk about SAX
Waldo2k2 is offline

09-05-2003, 02:42 PM	#9
Drutten Registered User Join Date: Aug 2003 Posts: 7	I'm about to take my MS deg. in eng. so I have some basic knowledge in physics. But if your drive isn't brand new then the noise from past writings (regard one bit as an area where maybe not the entire area is affected by the wipe-write...thus traces left in the outer part of that area) should be pretty random, and if you wipe with random data how can that be interpreted to something useful?
Drutten is offline

09-05-2003, 02:47 PM	#10
Thantos & the hat of GPL slaying Join Date: Sep 2001 Posts: 5,732	Wouldn't writting ones to all the sectors before writing zeros be effective in covering up the orginal data?
Thantos is offline

09-05-2003, 03:03 PM	#11
Waldo2k2 PC Fixer-Upper Join Date: May 2002 Posts: 2,001	become a hacker, do that to your drive, and see if they can't still convict you. __________________ PHP and XML Let's talk about SAX
Waldo2k2 is offline

09-05-2003, 03:24 PM	#12
Drutten Registered User Join Date: Aug 2003 Posts: 7	I'm not trying to wipe anything just curious why all these repetitions. It takes quite a while wiping the empty space just once on a drive. Does it really make a real difference ?
Drutten is offline

09-05-2003, 04:32 PM	#13
confuted Pursuing knowledge Join Date: Jun 2002 Posts: 1,916	If you REALLY need to destroy some data, I would highly advocate a physical destruction rather than hoping some program can do it for you. If you open the hard drive, you could shatter the platters with a hammer. They're rather brittle. Or I suppose that if you have access to a very powerful electromagnet, that could do the trick. __________________ Away.
confuted is offline

09-05-2003, 06:03 PM	#15
Waldo2k2 PC Fixer-Upper Join Date: May 2002 Posts: 2,001	The company (or individual) who wrote the software wants the unwary user to feel like the program is actually going to work. And it will in nearly all common day needs...but don't trust it when the CIA comes busting down your door...not that they will, but that's what we're all getting at. There's really no point in writing over it that manytimes, if someone REALLY wants the info on your drive, they can get it. Such is the world of electronics. __________________ PHP and XML Let's talk about SAX
Waldo2k2 is offline

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