Easy Way to Destroy HDD with bad sectors and private data?

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Modelworks

Lifer
Feb 22, 2007
16,240
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Also, do you have an evidence that the NSA actually does as you say?
I can show you http://en.wikipedia.org/wiki/DOD_5220.22-M
which describes the data shredding technique via writing random data and approved by the US DoD.


Those standards for the DOD were created when drives were the size of a pc they are not used anymore. I have seen the procedure for drives that are classified secret or higher. It requires three people. One is a security guard, one is the technician doing the drive removal, one is the witness to the removal that all procedures were carried out properly. The drive is removed and immediately placed in a shredder. The drive cannot be placed on a shelf or table when removed and must be shredded immediately. They specifically illustrates the removal from pc and directly into the shredder. Once shredded the shreds of metal are placed in a clear plastic bag closed up with a red tape tag with black writing that has the department number and the section number. Those shreds are then sent for final destruction where they are melted down and the resulting metal is stored in a secure location.

I made the remark the first time that I saw the procedure that I thought that was a bit overkill since shredding would be enough. I was quickly reprimanded by a senior officer that security was never overkill and if I had a problem with that I should leave for just making the remark. If they even suspect you are not 110% serious about security you get re-assigned.
 

FishAk

Senior member
Jun 13, 2010
987
0
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...Those shreds are then sent for final destruction where they are melted down and the resulting metal is stored in a secure location.

Unless you put the resulting metal into a black hole, you aren't really serious about security, because it will still be theoretically possible to glean information from it.

...If they even suspect you are not 110% serious about security you get re-assigned.

A rock can't be more than 100% rock. Saying 110% implies the very lowest end of an infinite scale.

I bumped a 1TB external drive, and toasted the spindle. I was traveling at the time, with only a small screwdriver for a tool. I opened the drive, removed the platters, and removed the magnet from the motor. I wiped the both side of each disk with the largest piece of the magnet (it came out in pieces), rubbed the plates on the sidewalk outside, and then bent them in half. I then tossed one platter in a dumpster outside the hotel, one at the airport with the McDonalds trash, and the third I pushed into the dirt in a park at my destination city.

Now I just use TrueCrypt, so even re-assigned sectors can't be recovered.
 

taltamir

Lifer
Mar 21, 2004
13,576
6
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Those standards for the DOD were created when drives were the size of a pc they are not used anymore. I have seen the procedure for drives that are classified secret or higher. It requires three people. One is a security guard, one is the technician doing the drive removal, one is the witness to the removal that all procedures were carried out properly. The drive is removed and immediately placed in a shredder. The drive cannot be placed on a shelf or table when removed and must be shredded immediately. They specifically illustrates the removal from pc and directly into the shredder. Once shredded the shreds of metal are placed in a clear plastic bag closed up with a red tape tag with black writing that has the department number and the section number. Those shreds are then sent for final destruction where they are melted down and the resulting metal is stored in a secure location.

I made the remark the first time that I saw the procedure that I thought that was a bit overkill since shredding would be enough. I was quickly reprimanded by a senior officer that security was never overkill and if I had a problem with that I should leave for just making the remark. If they even suspect you are not 110% serious about security you get re-assigned.

I heard that story before, I am not sure if it was from you or if they really are that stupid. Also this is still just he said she said vs actual published government documents.
Finally, only when the drive is melted is it as securely destroyed as the writing all 0s.
 

SilthDraeth

Platinum Member
Oct 28, 2003
2,635
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That is one heavy duty shredder. Unless the guy doing the distraction is allowed to remove the disks from inside the hard drive case. The hard drive case itself has some pretty fricken tough steel plates around it.
 

taltamir

Lifer
Mar 21, 2004
13,576
6
76
You think not?
A proper encryption would take far to long to crack. discard the key, then full format the drive (so they have to recover the data before they can even try to crack) and you are good.
 

Mark R

Diamond Member
Oct 9, 1999
8,513
16
81
I heard that story before, I am not sure if it was from you or if they really are that stupid. Also this is still just he said she said vs actual published government documents.
Finally, only when the drive is melted is it as securely destroyed as the writing all 0s.

I've seen the UK government regulations, and they are pretty similar.

However, the UK has a very complex flow-chart as to what type of wiping can be used.

They recognise 7 levels of data sensitivity:
0: Of no sensitivity
1: Trivial sensitivity (less than £10 financial loss if stolen)
2: Minimal sensitivity (less than £1000 financial loss if stolen)
3: Mild sensitivity (less than £100,000 - or threat to a small company's operations)
4: Moderate sensitivity (less than £10m - or threate to a medium company's operations)
5: Severe sensitivity (less than £1 billion - threat to a major company/bank operation)
6: Extremely severe sensitivity (more than £1billion - or threat to national security or national economy; top secret)

3 methods of wiping are recognised
a: Wiping - zero filling the drive using an approved software program
b: Purging - Destroying any magnetisation in a magnetic disc and/or the use of an approved software program rated for purging of drives (*)
c: Destruction - Shredding of the disc into fragments smaller than 20 mm (standard level) or 6 mm (higher level).

There are a whole set of complex tables describing how sensitivity levels are altered by different methods of wiping. From 'no change' from the use of a non govt approved software, 'reduce by 2 if starting from less than 4' for wiping with an approved software, etc.

The recommendation (but not regulation, except at level 6) is that multiple techniques be used, as a 'failsafe' in case somehow, someone doing the data disposal screws up. E.g. a drive would be wiped, degaussed (purged) and then shredded. This way, if a drive gets 'liberated' during the process, it's unlikely to be useful.

However, once shredded, no further action needs to be taken. There is no recommendation for melting down, grinding into dust, etc.

What is interesting is that the regulations don't address SSDs - it's possible that there is official guidance available for purchase. But freely available documents simply say "for SSDs seek expert advice". I knew a guy many years ago, who claimed to have read a poprietary program out of an EEPROM using a scanning electron microscope, when reverse engineering a device. I'd imagine that the same is possible with flash - of doubtful practicality though.


(*) - purging software is differentiated from wiping software by offering advanced features - such as the use of the drive's 'secure erase' function, detection and overwriting of bad sectors, detection and removal of 'hidden partitions' and 'protected areas'.
 

taltamir

Lifer
Mar 21, 2004
13,576
6
76
I've seen the UK government regulations, and they are pretty similar.

However, the UK has a very complex flow-chart as to what type of wiping can be used.

They recognise 7 levels of data sensitivity:
0: Of no sensitivity
1: Trivial sensitivity (less than £10 financial loss if stolen)
2: Minimal sensitivity (less than £1000 financial loss if stolen)
3: Mild sensitivity (less than £100,000 - or threat to a small company's operations)
4: Moderate sensitivity (less than £10m - or threate to a medium company's operations)
5: Severe sensitivity (less than £1 billion - threat to a major company/bank operation)
6: Extremely severe sensitivity (more than £1billion - or threat to national security or national economy; top secret)

3 methods of wiping are recognised
a: Wiping - zero filling the drive using an approved software program
b: Purging - Destroying any magnetisation in a magnetic disc and/or the use of an approved software program rated for purging of drives (*)
c: Destruction - Shredding of the disc into fragments smaller than 20 mm (standard level) or 6 mm (higher level).

There are a whole set of complex tables describing how sensitivity levels are altered by different methods of wiping. From 'no change' from the use of a non govt approved software, 'reduce by 2 if starting from less than 4' for wiping with an approved software, etc.

The recommendation (but not regulation, except at level 6) is that multiple techniques be used, as a 'failsafe' in case somehow, someone doing the data disposal screws up. E.g. a drive would be wiped, degaussed (purged) and then shredded. This way, if a drive gets 'liberated' during the process, it's unlikely to be useful.

However, once shredded, no further action needs to be taken. There is no recommendation for melting down, grinding into dust, etc.

This is a sensible and realistic approach.
The biggest advantage of destruction is that you can confirm the successful completion of the process visually. And you have to consider the possibility that the people doing the destruction might be enemy spies. A spy for example could bring a fake wiping software that looks like a legitimate one and claims to destroy all data but actually doesn't.
Taking a national security / over 1 billion euro damages drive and wiping it, then purging it, then grinding it makes sense in that regards. And the methods of destruction (wipe then purge then shred, don't guard) make a whole lot of sense compared to taking the unwiped drive, shredding it, bagging and numbering it, then melthing it by itself and keeping the slag under guard.

They also:
1. Perform a wipe before destroying it (wiping provides superior data destruction then shredding, if it is actually performed that is and not a spy pretending to do so)
2. They don't guard the worthless slag.
 
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hal2kilo

Lifer
Feb 24, 2009
26,146
12,349
136
I would but they are too stupid to listen. Speaking of government security... Tell me, how effective as the TSA been?
Also, do you have an evidence that the NSA actually does as you say?
I can show you http://en.wikipedia.org/wiki/DOD_5220.22-M
which describes the data shredding technique via writing random data and approved by the US DoD.
EDIT: PS. you and others suggested buffing it, drilling it, and hitting it with a hammer. None of you suggested melting it in a proper kiln (completely melting it) or grinding it to dust, both of which are things a government / army has the means to but the OP and the average home user doesn't. Grinding it to dust and hitting it with a hammer are completely different.

Not for TS data.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
I heard that story before, I am not sure if it was from you or if they really are that stupid. Also this is still just he said she said vs actual published government documents.
Finally, only when the drive is melted is it as securely destroyed as the writing all 0s.

The closest document publicly available would be this one:
www.nsa.gov/ia/_files/government/MDG/NSA_CSS_Storage_Device_Declassification_Manual.pdf


It isn't complete but gives a rough idea of what the procedures are. They became much more stringent after 9/11 and added that drives not just floppies and cdrom were to be shredded. Those documents are not public though for some reason, I have a copy but will not publish them since the NSA thinks there is something in them worth keeping private. Looks the same as the above one with just extra information but that is the NSA for you, paranoid to the extreme.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
That is one heavy duty shredder. Unless the guy doing the distraction is allowed to remove the disks from inside the hard drive case. The hard drive case itself has some pretty fricken tough steel plates around it.

It is the complete drive. The shredder is about the size of a small refrigerator. Instead of teeth like some might think, it has two steel rollers that have notches that are misaligned just enough to catch whatever you insert, looks sort of like a cam shaft in a car. It is noisy but it only takes it about 10 seconds to consume a drive.

Here is a company that sells them
http://www.ameri-shred.com/Hard_Drive_Shredder-Series1.html


video of machine in use
http://www.youtube.com/user/AmeriShred?feature=mhsn#p/u/2/Uw7h4hnWtbA
 
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Modelworks

Lifer
Feb 22, 2007
16,240
7
76
What is interesting is that the regulations don't address SSDs - it's possible that there is official guidance available for purchase. But freely available documents simply say "for SSDs seek expert advice". I knew a guy many years ago, who claimed to have read a poprietary program out of an EEPROM using a scanning electron microscope, when reverse engineering a device. I'd imagine that the same is possible with flash - of doubtful practicality though.

The NSA guidelines for SSD are that SSD or any eeprom/flash device be incinerated at 1600C until the contents have been reduced to ash of sand like size.

EEPROM can be recovered if erased. I have done it with Pic micro controllers. The key is understanding exactly how the specific chip does the erase . Each chip , even from the same manufacturer, has its quirks on how it erases the data. For the pic I just altered the voltage supply to the chip starting at the absolute lowest voltage, 1.74V , doing 10 reads , then incrementing the voltage by .01V each cycle of reads. The threshold was so much lower than the chips need for at least 4.5V to run ,that the chip often returned recently written bits as sometimes 0 and sometimes 1 , I added up the results and found that the bits that swapped were the ones recently changed. Combined that with the other information I gathered and recovered the flash to about 97%.
 

Blain

Lifer
Oct 9, 1999
23,643
3
81
Easy Way to Destroy...

Is there an easy practical way to destroy a harddrive so that nobody could read the data if they find it? I'm looking for something that does not involve explosives or firearms or equipment that is only found at construction sites.
The 8-15lb. sledge method doesn't require a 1600C incinerator or 40 ton HD shredder.
 

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
I've tossed them into a molten vat of steel before but the usual is a sledge in the driveway.
 

FishAk

Senior member
Jun 13, 2010
987
0
0
Now I just use TrueCrypt, so even re-assigned sectors can't be recovered.

You think not?

It's possible to brute force the key in the same sense that I could win the Power Ball each week for the rest of my life by buying a single ticket each week. I like those odds.

The other possibility is that the NSA has a backdoor to TrueCrypt that no one knows about. If so, they will certainly not risk it's discovery by disclosing that they were able to decrypt my disks. They have much bigger fish to fry, so I like those odds too.
 

bryanl

Golden Member
Oct 15, 2006
1,157
8
81
bryanl said:
Nothing short of opening the HDD and mechanically damaging the platters will assure data security.
this is false, mechanical damage to the platter provides inferior data destruction to magnetic destruction (writing 0s). although realistically physical damage with sanding and drilling as you suggest would be effective as well.
I agree, but OP wanted something easy. Waiting hours to zero out a drive the conventional way isn't easy for the impatient or those who need to destroy several drives, and few people have magnets strong enough to assure erasure unless the drive is opened up. I know a person who thought he had done a good job on desktop HDDs with a bulk tape eraser and was surprised when 2 drives were pulled from his pile and could be read.
 
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bryanl

Golden Member
Oct 15, 2006
1,157
8
81
hal2kilo said:
Tell that to the NSA where classified hard drives are sent to be ground up in big grinder.
Also, do you have an evidence that the NSA actually does as you say?
I don't know what the NSA does, but the US Army has a facility at Fort Huachuka, Arizona, where old hard drives are degaussed and then sent through a metal shredder. I don't believe it grinds them to powder.
 

mjrpes3

Golden Member
Oct 2, 2004
1,876
1
0
A platter is like a piece of glass; hit it a couple of times with a hammer and it should break into many pieces. Shake the drive afterwards and you should hear the success of your work.
 

Voo

Golden Member
Feb 27, 2009
1,684
0
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It seems we have this discussion every year and somehow we still end up discussing it again (funnily last time we also got a short detour to encryption algorithms)

But oh well, let's just cite some official documents for once:
NIST 800-88 said:
Advancing technology has created a situation that has altered previously held best practices regarding magnetic disk type storage media. Basically the change in track density and the related changes in the storage medium have created a situation where the acts of clearing and purging the media have converged. That is, for ATA disk drives manufactured after 2001 (over 15 GB) clearing by overwriting the media once is adequate to protect the media from both keyboard and laboratory attack.

Now this doesn't mean that government agencies will do this, but that has more to do with some other facts: Overwriting large drives takes a whole lot of time, while shredding them can be done in seconds. You have one large up front cost (the shredder) but avoid lots of problems and having to figure out how to redistribute the drives and so on - hardly worth the time for some drives.
 
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