Numerous references on the internet suggest that drilling through a hard-drive’s platter in one or more spots assures that no data will be recoverable.
As an alternative, I’m contemplating the destruction of a hard drive by folding it 90 degrees in a hydraulic press. This will of course squash the case and other components into the surface of the platter, which I would think will be adequate to prevent any practical effort at recovering data.
Some sources on the internet suggest that it may be possible to recover data from areas of the platter that are undamaged, e.g. if you drill two 1/2" holes through the platter, ~80-90% of the data could still be recovered. Is this:
A)theory, as in “the magnetic imprints on the unblemished areas still exist, and IF you could identify the original center of rotation of the platter and sweep a read/write head over just those areas, you could theoretically recover those fragments of data”, or
B)fact, as in someone out there has actually recovered data from sections of a hard drive that has been drilled through or otherwise catastrophically damaged?
Aluminium + rust. Ignite with a strip of magnesium. If you are going for total destruction, thermite is a good bet.
That said, a powerful electromagnet would probably do the trick, unless someone really, REALLY wanted to get at your data, and even recovering a small fraction could be damaging.
Edit: theoretically if you could balance the platter to compensate for the drilled holes, you could pop the platter into a new case and recover a significant amount of data.
Beat the crap out of it with a hammer, then dump the whole thing into a bucket of salt water for a week or so…
There are some recovery companies out there and obviously the FBI, CIA, etc that could read some destroyed hard drives, but if there is no reason for any of the above to do so, then the hammer - salt water trick will stop cold any amateur…
If you are that worried, then run a disk wiper (35 passes) on it. Anyone with the smarts, hardware and time to read a drilled hard disk has better things to do that read personal or even most corporate random data.
yeah, heat should also demagnetize most media, if the emulsion doesn’t fry first? What’s the emulsion for suspending magnetic particles on modern hard drives?
If you bend the platters so that they are no longer planar - even a tiny amount - the drive will be unrecoverable to all but the most well-funded government labs. To recover the data from a bent platter would require a robotic XYZ head positioner, and that’s something that your average data recover service doesn’t have. Thermite, saltwater and hydraulic presses are pretty much overkill.
Oh, and darrakk - a big electromagnet is probably not sufficient. Mechanical damage is the way to go.
Who’s going to be recovering your data? The NSA? Nobody knows exactly what the NSA could or couldn’t do if they decide that recovering your data is vital to national security. Or some 15 year old kid who buys your used drive from PC Recycle?
What are the consequences of having your data recovered? Jail time? Credit card number stolen? Bank account login information stolen? The Russians nuke Chicago? Your wife finds out about those pictures?
Credit card thieves have better uses for their time than buying old hard drives and hoping to recover some valuable information.
Some clarification is in order; sorry for not being more upfront.
This is a job for work, and rather than one drive, it’s approximately 150 of them, so the process needs to be fairly quick and efficient. I don’t know what data is/was on them; it’s entirely possible some of them are from HR and contain personal identifying info for some/all of our employees (e.g. SSN’s, bank account info for payroll deposits, etc.). Some other drives may contain proprietary/confidential info.
I’m pretty sure folding them in a hydraulic press will result in an extremely low probability of data recovery. Mostly I was curious to know just how badly a drive has been mangled and still actually been able to have data retrieved from it.
I post this every time someone says “Use a big magnet” - several years ago we were asked to wipe the hard drive of a notebook. Rather than firing up DBAN and waiting for it to complete we decided to try popping the hard drive out and using the big tape/drive degmagnetizer. It has specific instructions for wiping a hard drive (put drive on demag surface, turn on device, rotate drive three times, flip drive over and repeat).
Made a hell of a racket (constantly changing magnetic field was making parts inside the drive flutter around). We put the drive back into the notebook, powered it up and…it still worked perfectly. Didn’t do a damn thing to the data on the drive.
So skip the magnets. If you’ve got the space to plug in all those machines, make some bootable DBAN CDs and boot the computers from CD, then run the autonuke routine - that does a standard triple overwrite of the entire drive and it should be good against non-NSA type recovery efforts.
If you want to do physical destruction, I guess crack the cases open, take all the platters out and smash them. That’s a ton more effort than I’d go to and I work at a large law firm, lots of confidential data here. We do secure erasing of drives, either onsite or with a trusted 3rd party that specializes in that kind of work.
This is what we do at work. Once you start the autonuke process, you can ignore the computer until DBAN completes. And you can even remove the CD and use it in another computer once the program loads. If some of the computers can’t boot, you can move the drive to a known good working one and wipe it there. We keep a couple of old computers that have conventional ATA/IDE drives in them, in case we need to wipe the older type of drives. (Because one minor flaw that I found with DBAN is that, as far as I can tell, it can only wipe the primary drive on a system, so you can not stick a drive in an external enclosure and wipe it using DBAN but instead need to put it in the system as the boot drive.)
For those saying that magnets don’t work, there’s plenty of videos on YouTube of people killing hard drives with magnets; ironically, including magnets from hard drives (see this example, starting at 7:30; note also that this drive has no R/W head on the top platter, so it didn’t happen from being accidentally touched by the magnet). I have tried this myself, with a microwave magnetron magnet and the drive (not opened up) immediately began the “click of death” (this was an older drive, a few GB from an otherwise working computer somebody threw out). Note, the hard drive was running when I did this; a non-functioning drive wasn’t affected at all just by putting a magnet on it (to magnetize something, you stroke the magnet across it in one direction, which occurs with the platters spinning but not still).
If you have 150 drives to process, call a service - they will send a truck with a drive shredder, takes probably half a day.It will be noisy, but effective.
