Ten Ways To Destroy a Hard Disk

Barence writes "Following his blog last week about the homemade hard disk destroyer, Bustadrive, Mike Jennings was deluged with comments from readers, both on the blog and here on Slashdot. Most seemed to like the product, but also offered up far more innovative and madcap methods of hard disk destruction, with a wide range of implements used — household and otherwise. In this follow-up post, he rounds up the best of an imaginative bunch of hard disk destruction methods."

Comments

Missing option

[Anonymous Coward]

Install Vista on it?

Re:Missing option

[jcr]

That doesn't actually destroy the drive, it just make the drive wish it were dead.

-jcr

Re:Missing option

[cheftw]

lol @ ubuntu version troll

In before: "NO NO NO, here's the real versioning..."

How about: Write zeros to the disk?

[impaledsunset]

Write zeros. Once. Problem solved. Then you can sell the disk.

Physical destruction is only necessary if the disk is already broken, and you can't erase it properly.

Re:How about: Write zeros to the disk?

[gobbligook]

Not too sure about this one anymore. Back in the day certainly.

Re:How about: Write zeros to the disk?

[geekoid]

Now who the hell is going to trust a post from an NPC. Damn DM is trying to fool us again.

Re:How about: Write zeros to the disk?

[Anonymous Coward]

No he can not. There is not a single data recovery company in the whole wide world advertising this capability and there isn't a single lawsuit in which data from an overwritten disk has been used as evidence. Data recovery from overwritten hard disks is BULLSHIT.

Re:How about: Write zeros to the disk?

[impaledsunset]

He has a less chance to recover any data than if it was shot with a shotgun, as suggested by the article. I'm unconvinced that data can be retrieved back after the drive has been written with zeroes ones, much less that there are much people on Slashdot who would ever work with a hard drive that will end up at the good forensic IT guy, but for them there are better erasing programs. Certainly better than a shotgun, which might leave huge parts of the plates intact, if you don't shoot it enough times.

Re:How about: Write zeros to the disk?

[Rei]

I'm surprised they only had a list of ten. There must be 50 ways to wipe your platters.

Just give it a whack, Jack.
Smash it with a van, Stan.
Shoot it to destroy, Roy.
Just listen to me.
Soak it till it rusts, Gus.
You don't need to discuss much.
Toss it in the sea, Lee
And get yourself free.

Re:How about: Write zeros to the disk?

[zero0ne]

Citation?

I don't think there is a single legitimate source that has proved this is possible.

Re:How about: Write zeros to the disk?

[bmo]

Who the hell modded this informative?

It's perpetuating a myth.

Even Guttman says that with modern hard disks it's impossible to retrieve data once overwritten.

http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html

Epilogue
In the time since this paper was published, some people have treated the 35-pass overwrite technique described in it more as a kind of voodoo incantation to banish evil spirits than the result of a technical analysis of drive encoding techniques. As a result, they advocate applying the voodoo to PRML and EPRML drives even though it will have no more effect than a simple scrubbing with random data. In fact performing the full 35-pass overwrite is pointless for any drive since it targets a blend of scenarios involving all types of (normally-used) encoding technology, which covers everything back to 30+-year-old MFM methods (if you don't understand that statement, re-read the paper). If you're using a drive which uses encoding technology X, you only need to perform the passes specific to X, and you never need to perform all 35 passes. For any modern PRML/EPRML drive, a few passes of random scrubbing is the best you can do. As the paper says, "A good scrubbing with random data will do about as well as can be expected". This was true in 1996, and is still true now.

Looking at this from the other point of view, with the ever-increasing data density on disk platters and a corresponding reduction in feature size and use of exotic techniques to record data on the medium, it's unlikely that anything can be recovered from any recent drive except perhaps a single level via basic error-cancelling techniques. In particular the drives in use at the time that this paper was originally written have mostly fallen out of use, so the methods that applied specifically to the older, lower-density technology don't apply any more. Conversely, with modern high-density drives, even if you've got 10KB of sensitive data on a drive and can't erase it with 100% certainty, the chances of an adversary being able to find the erased traces of that 10KB in 80GB of other erased traces are close to zero.

Also:

http://sansforensics.wordpress.com/2009/01/15/overwriting-hard-drive-data/

What this means

The other overwrite patterns actually produced results as low as 36.08% (+/- 0.24). Being that the distribution is based on a binomial choice, the chance of guessing the prior value is 50%. That is, if you toss a coin, you have a 50% chance of correctly choosing the value. In many instances, using a MFM to determine the prior value written to the hard drive was less successful than a simple coin toss.

The purpose of this paper was a categorical settlement to the controversy surrounding the misconceptions involving the belief that data can be recovered following a wipe procedure. This study has demonstrated that correctly wiped data cannot reasonably be retrieved even if it is of a small size or found only over small parts of the hard drive. Not even with the use of a MFM or other known methods. The belief that a tool can be developed to retrieve gigabytes or terabytes of information from a wiped drive is in error.

--
BMO

Re:How about: Write zeros to the disk?

[gandhi_2]

Using this logic, all hard drives are capable of infinite capacity.

Re:How about: Write zeros to the disk?

[Pulse_Instance]

After shooting a hard drive with a shotgun once, I'm pretty sure you going to want to keep shooting it.

Re:How about: Write zeros to the disk?

[omnichad]

Thanks for posting this. I posted one of these links last time something like this came up on Slashdot, and I was too lazy to find them again.
 
It's just silly to believe that a device with such a wide margin of error on "normal" data leaves any room for recovery on a wiped drive.

Re:How about: Write zeros to the disk?

[omnichad]

They don't take chances. They don't research. They just do what it takes to be SURE. That doesn't mean that they aren't overly paranoid.

Re:How about: Write zeros to the disk?

[TheCarp]

Absolutely true.... there is an easy way to avoid that problem in two simple steps. Either one will work:
1. Don't do anything that will raise the ire of someone with access to an appropriate microsocope.
2. If you can't do one, then stop using hard drives from the 1980s. Dude, where do you even find disk controllers for them that work in modern machines?

-Steve

Re:How about: Write zeros to the disk?

[Anonymusing]

Maybe YOU can, with your handy electron microscope, but mine is still on layaway.

Also, suppose you were trying to recover a specific file from my disk, and you had to use an electron microscope to recover every single bit. There are 1,889,785,610,240 bits on my 220gb hard disk. Assuming one-tenth of a second per bit to scan, you'd still spend about 6,000 years reading the drive to collect all the data. Trust me: the value of that data will have long expired by then.

Re:How about: Write zeros to the disk?

[danieltdp]

Its like this: one close-range shotgun shot to the head kills a man. Wanna be sure the guy is dead? How many bullets do you have?

Re:How about: Write zeros to the disk?

[commodoresloat]

you'd still spend about 6,000 years reading the drive to collect all the data. Trust me: the value of that data will have long expired by then.

Not if it's porn!

Re:How about: Write zeros to the disk?

[CAIMLAS]

Oh, really. You should have one of those good forensic guys go here and accept the challenge on that page; it would be pretty financially lucrative, if what you say is true. But it isn't true; such a recovery is impossible until proven otherwise.

Re:How about: Write zeros to the disk?

[Lord Ender]

You are almost right, but not entirely. Some drive firmware (as I understand it) will detect failing sectors of the disk and mark them as "bad." Your software won't even see them, as this is done at the firmware level. This means your data will still be there on the disk, even after a zero-write.

Re:How about: Write zeros to the disk?

[Lord Ender]

No, it's true! As a forensic specialist, give me a disk that has been overwritten with zeros, and I can recover approximately 50% of the bits that were on the disk before it was wiped.

Re:How about: Write zeros to the disk?

[prockcore]

That and he's assuming that the harddrive actually writes out ones and zeroes. That's not how it works.

The harddrive stores information on the disk as a constant magnetic field, the only "information" on the disk is the polarity of the magnetic field. So a "bit" on disk is positive, or it is negative.

The harddrive stores information using flux reversal. A 1 is a flux reversal, a 0 is no change. So 1001110 is stored as +---+-++. Switching polarity is considered a 1, not switching is a 0. 1001110 could also be represented as -+++-+--, it all depends on the current polarity when the data is written. The harddrive uses RLL encoding, so 1001110 is actually written out as 01000010000100.

Also, you have to read the entire sector, since the data is xored together before it is RLL encoded. A single byte in a sector is garbage unless you xor it with all the bytes after it in the sector.

Re:How about: Write zeros to the disk?

[jcr]

Nobody's modded you funny yet? Come on, people!

-jcr

Re:How about: Write zeros to the disk?

[X0563511]

Where are your fucking shift and period keys?

Re:How about: Write zeros to the disk?

[sumdumass]

The D.O.D and NSA are forward thinking because many of their secrets can be potentially damaging well into the future. They aren't just looking at making them not readable today, but hopefully not readable 25 or more years into the future when new technology may be availible to obsolete the current limitations to our technology.

Making several passes attempts to increase the likelihood of that not being possible.

Re:How about: Write zeros to the disk?

[lgw]

Government protocol for destruction of a drive that has ever held secret data is to shred the drive until the pieces pass through a 1 mm sieve. No amount of "passes" will erase data on sectors that the drive firmware has marked "bad". 1 pass with random data is adequate to prevent recovery (on a GMR drive, and probably on any post-MFM drive), but only for those sectors the HHD firmware is still willing to write to.

In practice, the government often just sells the computer without taking any steps to delete the data. But hey, that's government for you.

Re:How about: Write zeros to the disk?

[Scarletdown]

Encrypt the drive first with whatever the strongest encryption available is and then write all zeroes to it?

Then even if you can recover 50% of the bits, you would not be able to do anything with them unless you can figure out how to crack the encryption.

Would that work?

Re:How about: Write zeros to the disk?

[thue]

A hard disk has inaccessible spare sectors, which will be logically swapped in if a sector fails. See http://en.wikipedia.org/wiki/Hard_disk#Error_handling

How do you guarantee that there isn't some important data lying around in the swapped out sector? It is not accessible via the hard drives external interface, but could be accessed by a raw reading of the disk.

Re:How about: Write zeros to the disk?

[number11]

Actually, the chances of two consecutive coin flips landing on the same side are EXACTLY 50%.

You statistics people think you're so smart.

But you have failed to account for the cases:
where the coin lands on edge.
where the coin rolls, and is lost under the refrigerator.
where a raven swoops down out of the sky and snags the coin midair and flies away with it.
where a man jumps out of the closet, grabs the coin, and runs away.
where when the coin hits, it breaks into two pieces, the microfilm flies out, and the pieces come to rest hollow side up.
where Annie Oakley shoots from the next room and blasts the coin to smithereens.
the Creationist case, where God, being extremely bored, miraculously causes the coin to turn into a glass of Guiness, which smashes to the ground and gets beer everywhere.
And probably other cases.

Where's your 50% now, eh?

Re:How about: Write zeros to the disk?

[revengebomber]

wh11111sh.

Re:How about: Write zeros to the disk?

[ciderVisor]

where a raven swoops down out of the sky and snags the coin midair and flies away with it.

I hate it when that happens. Scurrilous wee flappy raven bastards.

Re:How about: Write zeros to the disk?

[Scarletdown]

Okay, people, I give up. Can someone please explain why the guy I responded to was funny and what the joke is?

I thought that overwriting everything with zeroes or ones and zeroes was a standard way to "sanitize" a drive, and that these forensic specialists often find data recovery a trivial matter even after doing such a wipe.

I've reread the guy's post several times and am still not seeing what caused the funny bit to be set. (Blame insufficient sleep for this perhaps?)

Spot Welder?

[eldavojohn]

The average welding torch, meanwhile, is a fully paid-up member of the "life-threatening but enormously enjoyable" club - and there's no denying that a 3,000-degree flame would reduce the average hard disk platter to a pool of reflective liquid quicker than you could say "data protection". It's a superb suggestion from Steve, who also put forward the angle grinder for consideration. We're worried about him.

A not as messy method might be a spot welder. They go by different names but my dad's shop used to have a nice adjustable Miller spot welder that would function great for sheet metal work. Anyway, I can envision a homemade spot welder (very trivial to make) with a stand around it and two wooden 2' by 2' pieces of plywood with a handle grip sticking up and two hard drive holes counter sunk with a quarter inch lip to hold each drive (for 3.5" and 2.5" drives). Place the hard drive in the selected hole and clamp your spot welder on it and go to town. Mark your initials in it and you should have a pretty solid drive with no mess, no metal shreds laying around, no flying debris or sparks and probably easier to store/recycle/transport. Man, I wish I didn't live in the city and had a wood and metal machine shop.

Re:Spot Welder?

[Landshark17]

Homemade spot-welder is cool, but I think the truly epic way of destroying a hard drive must involve the Flaming Bacon Lance of Death: http://www.youtube.com/watch?v=w9dskxN10N0

Re:Spot Welder?

[BrokenHalo]

I used to be a blacksmith, and I still have my forge and tools. My favourite treatment is to heat the whole HDD assembly up to a nice orange/red colour (which is more than sufficient to demagnetise any media), then give it a few wallops with my 300 pound power hammer. The drive comes out about 1 millimetre thick, and I challenge even the most serious boffin to get any data off it after that.

Re:Spot Welder?

[zippthorne]

Don't do this with a ceramic drive...

You only need one

[Anonymous Coward]

Run bit torrent on a hard drive continuously until it dies. Works every time.

Re:You only need one

[Holistic Missile]

I have Comcast, you insensitive clod!

Magnesium

[Hubbell]

If you have the harddisk out of the shell, buy 1 package of sparklers, if it's inside it, get around 4-5 packages (the metal sticks with grayshit on them)

Strip the grayshit (magnesium normally, if its something else it probably wont work as well through the case) and crush it into a powder off of all sparklers but 1, you can strip the last one down to about an inch or so from the tip. Pile it all on the harddisk/shell, light the sparkler tip that's left, insert into the pile, and other than it appearing as though the sun is arm's length in front of you for 5-10 seconds, anything underneath shall be melted/vaporized due to the white hot heat released. I've melted through steel grills at my local beach at night this way before, around 11pm 1 package of sparklers prepared this way lit up the local beach on long island sound for about a mile in all directions as if it was daytime.

Re:Magnesium

[amplt1337]

And when you win a Darwin award, here I'll be able to say, "I knew him when..."

Re:Magnesium

[Hubbell]

How exactly would I get a darwin award for something which is nonexplosive? Magnesium merely burns white hot until it's all gone.

Re:Magnesium

[Obfuscant]

They were rolling George into the operating room to work on his multiple gunshot wounds and they asked what happened.

Well, the last thing I remember is, me and Billy Joe and Frankie and my brother George were in the Dew Drop Inn having a few beers, and Billy Joe says 'hey everyone, let's go huntin'!', and I said "I'm game."

Thank you very much, I'll be here all week...

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[account_deleted]

Comment removed based on user account deletion

the best way to render a hard drive useless

[Anonymous Coward]

install Windows ME

Ten Ways To Destroy a Hard Disk

[Shakrai]

1) .45 caliber 1911 style handgun (gets the job done)

2) .357 magnum revolver (gets the job done with a louder bang)

3) 10mm auto handgun (gets the job done and lets you pretend to be Ted Nugent)

4) .44 magnum revolver (gets the job done and lets you pretend to be Clint Eastwood)

5) 9mm handgun (gets the job done and lets you pretend that you have a real gun ;)

6) 12 gauge shotgun (gets the job done and looks/sounds really cool)

7) .30-06 rifle (REALLY gets the job done)

8) .50BMG rifle (useful if you run into a hard drive with armor plate)

9) .22LR plinking rifle (gets the job done in a cost effective manner)

10) .223 fired from an AR-15 (gets the job done while scaring the crap out of any nearby big city types that assume any black rifle with a pistol grip is a weapon of mass destruction)

Re:Ten Ways To Destroy a Hard Disk

[Eberlin]

Hey, I think I saw this guy at a healthcare townhall meeting!

Re:Ten Ways To Destroy a Hard Disk

[Anonymous Coward]

Shooting with a .223 can have other interesting effects as well (at least that's the one I noticed this on). I used a hypervelocity varmint load, light bullet, real fast, like 3800 fps, in a good rifle that can take that kind of overload. This was a plastic tip thing designed to more or less explode on contact -- even a piece of cardboard will make it go fragmented.

In shooting a floppy drive, one that really deserved it, I managed to hit the magnet for the drive motor, and powder it. The sudden disappearance of the field while still inside the windings made a high voltage pulse, a flash of lightning about 2 feet in diameter, and plastic parts flew 50 yards, and were burnt when recovered. As that drive had caused us no end of trouble, there was cheering all around.

Regardless of what you believe about being able to get things back from the part they *let* you write on....this just has to be more fun than that. Too bad for you city guys who can't experience this firsthand like us country boys with a legal shooting range on the back 40.

Next time we'll try Tannerite....heh.

Re:Ten Ways To Destroy a Hard Disk

[dotgain]

Oh my God someone used "loosed" correctly!

Leverage the spinning platters to your advantage

[bugg]

Everyone knows drives are most vulnerable when the heads are engaged, and the spinning platters should cause a single destructive action to potentially spread to the entire circumference. Why not do a write operation to the entire disk and hit it with a hammer during the write? Do that properly and the heads should go flying off in pieces into the platters, and the platters spinning with the loose head material should ensure nothing survives.

Re:Duh: use a WIll It Blend blender.

[impaledsunset]

And after you shred the disk with the blender, don't forget to try to return it to get your money back.

Easiest Destruction Method

[eldavojohn]

Give it to my sister. If her laptop and last five cell phones are any indication, it'll end up with vodka dumped on it after a party or smashed to pieces in the middle of the street or even at the bottom of a toilet in a club. You would never believe how frequently that last one happens.

I swear jean designers are in cahoots with cell phone manufacturers. Just slip your hard drive into the back pocket of a girl in a night club wearing tight jeans ... aw, who am I kidding, this is Slashdot.

The Actual List ...

[neonprimetime]

1 - The classic hammer
2 - "What's wrong with an angle grinder?"
3 - The average welding torch
4 - weaponry, from 12-gauge shotguns to high velocity rifles
5 - Science fans will be pleased to see an electromagnet on the list
6 - use a drill
7 - Hard disk platters are generally made from aluminium, which melts at 660.32C
8 - Electric log splitters
9 - An industrial shredder
10 - Finally, another method that scores valuable points for science: Thermite

Fastest way

[G-LOC]

1. buy rare earth magnet. 2. play with magnet. 3. place magnet in pocket. 4. sit down and put macbook on lap. 5. call apple support. 6. tell technician "err it no work" 7. write good review of apple support.

Re:Leverage the spinning platters to your advantag

[SOdhner]

I can confirm that this works.

...

Even if destroying the drive wasn't intentional. Sigh.

Nuke it from orbit!

[K. S. Kyosuke]

That's the only way to be sure.

I like the CIA/NSA method the most

[Skapare]

... which is to grind the device into dust, carried out entirely under supervision with all employees holding top secret clearances. I don't know where the dust then goes, but I doubt it's out of the country.

Re:The most fun...

[impaledsunset]

Trying to destruct a drive while the plates are spinning and the disk is open can be dangerous. I've done it a few times, but recently there are some manufacturers that make the plates from glass, and the glass can easily be crused if you do something to the plates while they're spinning, or you spin them too fast. I knew a kid who had been injured by hitting a glass plate of a hard drive while it was spinning.

Become a plumber

[lttlordfault]

After reading the parent article, one thing I noticed was that welding torches and angle grinders seem to create a sense of well being within your average geek. I have to say, as a plumber who also has a keen interest in all things technological, there's nothing more satisfying than breaking into something with either a blow torch, angle grinder or a drill. I love my job, that I have to use these tools every day gives me great satisfaction and makes me feel like a real man :D

When going through higher education I was originally aiming for a career in IT but half way through decided I didn't really fancy sitting at a desk all day. Becoming a plumber has definitely been the best decision I ever made, I get to work with really cool tools every day, plus I'm at the top of my profession having started plumbing about 6 years ago. I'm one of only 3 people qualified at my level in Mid Wales, and so am in incredible demand. I mainly work on servicing/maintenance on commercial/industrial heating and ventilation systems and see some incredibly cool tech every day. Sorry to brag, but as a self confessed geek, I have to say, plumbing is freaking awesome!

Kinda off topic, sorry about that. I don't often have any connection with anything posted on /. but like to read about it anyway.

Re:Become a plumber

[couchslug]

You are also in a trade that will be in demand longer than you will live, can not be outsourced, whose services all modern humans require, and whose required skill set makes you a versatile fellow.

"I mainly work on servicing/maintenance on commercial/industrial heating and ventilation systems and see some incredibly cool tech every day."

Mmm. No shit piping! What's not to like? :)

How to ensure all data is lost

[Burning1]

My favorite way to ensure all data is lost on an hard disk is to store the only copy of my Master's thesis on that drive.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Sometimes the hammer has drawbacks

[Erbo]

I had some old hard disks I needed to destroy a while back, so I thought I'd just open up the cases and then pound the platters into submission with a hammer. I did this on the kitchen floor.

Unfortunately, the first drive I opened was an old IBM DeskStar. I had forgotten what DeskStar drive platters were made of...

One swing and I had to call a halt to the whole operation while I swept a metric buttload of treacherous fragments of shattered glass up off my kitchen floor.

I conducted the rest of the destruction outside, near the Dumpster.

Re:Sometimes the hammer has drawbacks

[EkriirkE]

Looks like; cood head crash photos: http://www.astro.ufl.edu/~ken/crash/index.html

Awesome

[otopico]

Hey, rather than find a way to reuse a complicated piece of tech, lets play like cavemen and come up with awesome ways to break it so no one can do anything with it.

Sure, some data is too valuable to risk, but it is 2009, you would think we would have a non-physically destructive way to securely erase data rather than a hammer.

The scope of the pure wastefulness of this is just sick. Yeah, I'm probably in a minority, but this logic is why our landfills leach out heavy metals into the water table.

America used to be resourceful and frugal.

Burn it up in the atmosphere

[mb-texas]

See the "TubeSat Personal Satellite Kit" post from August 2nd: http://science.slashdot.org/story/09/08/02/1653256/Orbit-Your-Own-Satellite-For-8000?art_pos=8

A freind of mine once....

[BigGar']

.. discovered the fastest way to destroy a hard drive. It was to put the only copy of his PHd. dissertation on one.

Re:Leverage the spinning platters to your advantag

[hurfy]

Hmm, i don't think it will work so well on modern drives but we had an old hard disk from our mini computer turn itself into a metal lathe one night. Came in the next day to find a whole room full of aluminum shavings. Shredded several of the 11" platters into nothingness. After the pieces went through the fan nothing was more than 1/8 x 1". At least everyone understood the value of the offline backup.....

Very effective data destruction however it was a tad messy after it blew about a million aluminum curly-Q's all over the place.

The part even harder to picture these days....they repaired the drive!

Most of the new stuff is probably too hard to convince to destroy itself nearly so well :(

Drill Press

[ManuelKelly]

I use my drill press to drill a 1/4" hole thru some of the chips and the platters.

Anyone who wants to spend enough to get anything off of it after that is happy to do so.

For a load of corporate data a couple of holes would probably do it. After that it would be easier to burglarize you and get a live disk or machine with the data on it.

simple way

[DragonTHC]

dd if=/dev/zero of=/dev/hda

My method of HDD disposal

[kheldan]

1. Remove drive from computer
2. Dismantle drive, remove platters and magnets
3. Use magnets for interesting things
4. Either: Use platters for interesting things, or: Destroy platters (bending them up works well)
Cost: essentially nothing.

Re:My method of HDD disposal

[Poppageorgio]

I work in law enforcement IT, and we routinely dispose of drives that have sensitive data on them. This is our technique. We strip the magnets and keep them on the workbench to hold screws when we take things apart, then smash the platters with an 8lb sledge hammer. If you can recover the data after a sledge hit, you're smart enough to go about obtaining this data another way!

train

[Hellswaters]

One up the little kids putting the penny on the rail tracks . This should pretty much destroy it. If the train destroys it, the fireball should do the rest.