Just wondering in case something happens and I need to wipe all my data right away. I don't care if the drive is unusable after wipe.
13thermite .. though it's a little destructive ;) ... how fast is "instant" in your mind?– warrenJan 20, 2012 at 22:24
3I'm just pretending this person is in another country with a government that is more interested in self-interests and oppressing the majority, like...nah, won't say it. I'm just going to assume the OP is Batman.– Bart SilverstrimJan 20, 2012 at 22:32
8Encrypt the data in the first place.– ZoredacheJan 20, 2012 at 22:37
3@zzatkin funny questions breed funny answers ;)– Mathias R. JessenJan 20, 2012 at 22:55
3Related: serverfault.com/questions/3854/how-do-i-destroy-a-hard-disk serverfault.com/questions/8217/hard-drive-disposal superuser.com/questions/34940 superuser.com/questions/10114– BlueRajaJan 20, 2012 at 23:02
Violent smashing with hammers.
1Cats are not NSA-approved methods of disk destruction. Yet.– voretaq7Jan 20, 2012 at 23:24
Given enough time and effort, someone could reassemble shattered drive platters into a somewhat readable state and mount the platters into a second device. Jan 20, 2012 at 23:52
The NSA uses a grenade and an enclosure specifically designed for this purpose. I really do know this from experience. Jan 21, 2012 at 0:53
1Given enough time and effort, Doc will create a time machine so him and Marty can go back in time and hit you with a crowbar before you hit the hard drive with a hammer.– WesleyJan 21, 2012 at 3:43
1Post a hammer, get a badge!– WesleyJan 22, 2012 at 6:04
Get a commercial degausser, a sledgehammer, and a gun. Use them on the drive in any order.
Short of an extremely powerful degaussing, there is no instant method to immediately erase all data from a drive.
If you're looking for a software related solution, you're out of luck. It would have to write junk data to each sector many times over to have the desired effect, which takes time.
Having bashed many disks over time, sledgehammers aren't really all that instant. Takes many whacks on some of them to have an effect. Guns won't necessarily prevent data recovery companies except where the bullet damaged the media...degausser would probably be best. Or a really big rocket aimed at the sun. Jan 20, 2012 at 22:30
1@BartSilverstrim Modern disks (ceramic platters) are much easier than the older ones: A good solid WHACK with a basic claw hammer will shatter a section into dust, and four well-placed hits can turn a drive into an expensive Maraca :)– voretaq7Jan 20, 2012 at 22:48
I threw a disk of a 4 story building once. The drive looked relatively intact afterwards, but it sounded like a maraca when shook - the platters had been shattered into powder. Jan 20, 2012 at 23:26
Also, assuming you are shooting in the correct section (perpendicular to the hard drive), any decent cartridge (e.g. not .22 LR) will penetrate through the entire drive, including the platters. I don't think there is much chance of recovering data from a hard disk platter with a bit hole in it. Jan 20, 2012 at 23:28
1My favorite way. Don't use the tailgate of your truck youtube.com/watch?v=PS3sAWF5S1I A .50 caliber armor piercing round has been known to pierce up to 17 drives at a single shot. Jan 21, 2012 at 0:10
Use full disk encryption. If there is a key at a certain part of the drive that is needed to read the rest, all you should need to do is get that scrambled. Make sure there isn't a copy in the ram of the system somewhere.
Not entirely fail safe. If a vulnerability is discovered down the road, your data is as good as plaintext. Doing this is making a bet that no one will ever crack whatever algorithm you are encrypting your drive with.– MDMarraJan 20, 2012 at 22:32
5Of course, that invites this: xkcd.com/538– cjcJan 20, 2012 at 22:33
Well, quantum computing can render all current encryption pretty much moot...but we still use it. :-P Jan 20, 2012 at 22:34
All the other solutions seemed to be based on physical destruction. This solution provides an extremely quick erasure. It does all depend on how the FDE is implemented. But if its implemented as I "hope" then even the XKCD comic wont work. "Q. What the key used to encrypt the hard drive? A. I don't know, all I did was type in password, and that unlocked the key used" Jan 20, 2012 at 22:41
@Bart: That's only true of algorithms that rely on the difficulty of factoring, or similar probably-not-NP-complete problems. The only real examples I know of are Blum-blum-shub, Diffie-Hellman, and of course, RSA. AES and most other block-ciphers would be completely unaffected. Jan 20, 2012 at 22:52
Thermite. Degausser. Those are as instant as you can get, I suppose. Degausser won't burn your house down.
Some acids might work as well, or at least no one would touch it until the acid works.
Might I suggest that unless you have some great rube-goldberg-esque alarms to trigger this reaction using something like full-disk encryption?
Thermite is about the slowest reacting pyrotechnics that exists. It is hard to ignite, and reacts slowly - not instantly. Jan 31, 2019 at 9:05
Every home should have one.
Realistically, every bit on your platters is recoverable. A single, full-pass write of the disk is the only way, and even then it's still possible to get something off it (but it's very hard). Destroying the disk by buckling or smashing the platters is the fastest way. there's till ways, but it's the kind of stuff only decent sized governments can be bothered with.
You could perhaps try to overwrite the first block of each file and then overwrite the filesystem, which should put it beyond a cursory recovery job, but not anyone more determined.
Ask yourself: What is it worth to my enemies to get hold of what's on this disk?", and take the appropriate measures.
I love that machine Jan 20, 2012 at 22:36
I like how the sheer force of the rotary chippers causes some drive components to burst into a shower of sparks. And they're catching it in a cardboard box... heh! Jan 20, 2012 at 23:54
Or you could just avoid illegal activities. Then when the gub'mint comes and takes your computer, they won't find any incriminating data.
But if you must surf nefarious sites, do so using a diskless laptop booting off of a live cd, connected to the free wifi at the nearest burger joint or coffee shop.
For data storage, use the cloud, logging in with a user account that you NEVER use from a computer with writeable media.
That said, the contents of RAM may still be recoverable. You'll also need a means of ensuring that data is rendered inaccessible, as well.
I'd consider recovering from RAM theoretical at this point. Not too many LEO's carrying liquid nitrogen these days. Jan 20, 2012 at 22:49
@Aaron: See my comment to security.stackexchange.com/a/10644/1508 Jan 20, 2012 at 22:59
1@Jonathan: Not everyone wants to destroy a hard-drive because of illegal activities: trade secrets, tax/medical documents, confidential government files etc. Jan 20, 2012 at 23:04
@BlueRaja, it's unlikely that legal confidential files will need to be destroyed quickly and immediately. Jan 26, 2012 at 20:42
Conventional hard drive (spinning discs)
I believe the fastest and surest way is a hard drive degausser. This will demagnetize the hard drive platters. The drive won't work afterwards because some data on the platter isn't meant to be erased and this method is likely to damage some of the hard drive mechanisms. The degausser itself costs close to $10k. Weaker degaussers intended for tape erasure won't work on hard drives.
Second fastest is probably a hard drive shredder. This is a special piece of grinding equipment that you feed a hard drive in one side and get a pile of metal shavings out the other side. I couldn't easily find pricing, but I assume it's expensive since it's usually sold as a service not a device. This has the advantage of verifiability over a degaussing solution (you can tell whether or not it worked), but is much messier.
Anything that bends or breaks the platters will render the data unreadable to all but the most sophisticated (a G8 government that views your information as worth millions). A big hammer would probably do the trick, especially if you open up the drive so that you're hitting the platters and not just the casing. An industrial press should do it, too. There's commercial versions specifically made for hard drives.
You could open the drive up in a few minutes and apply a belt sander to both sides of all the platters. Removing the shiny stuff from the platters removes and randomizes the data so that nobody can get it back.
If the drive still works, overwriting the entire drive with a single pass of zeros, ones, or random data is sufficient as long as you don't have data worth millions to a major (G8) government. Depending on drive size and speed, this could take hours.
Solid State (SSD)
If it's a solid state drive, you need to destroy all the chips.
If doing it in software, you have to use special secure erase commands. Simply overwriting as with a disc drive won't work.
Preparing for next time
If this is a common need for you, consider using full-drive encryption so that you only have to erase a key, not a whole drive.
Drill a hole into it.
This I've been told by someone who works for a company that is specialized in destroying data.
DBAN isn't fast enough for you :P?
Sounds like a ZOMG THE FBI'S AT THE DOOR after a late night hacking jag that turns out to be the Pizza you ordered turning up a couple hours late. Jan 20, 2012 at 23:49
I believe a faster way (assuming SSD) than any yet mentioned is to check your motherboard and bios for support for the ATA secure-erase feature and then make a bootable thumb drive which makes the appropriate hdparm() calls.
Please note I have not yet tried this, and all of the information I am saying is from feedback to a question I asked on askubuntu, but comments there suggest it would be faster than even a hammer. I have never tried any of this, and it CAN PERMANENTLY DAMAGE HARDWARE... I hear.
1Takes time for it to zero from center to edge. Larger the disk, the longer the time. Doesn't damage the drive, merely is a supported drive wipe command. Immediate data wiping requires immediate physical force or a very intense magnetic field to scramble the platters. Jan 20, 2012 at 23:47
1Immediate claim and speed better than hammer are dependent on SSD.– MikeyJan 21, 2012 at 0:44
I don't have a reference, but I did read a (public) government white paper, FBI?, about this question once.
It concluded that it would be sufficient to burn the drive in a fire hot enough to melt all the individual components, but that no lesser method is completely reliable. (Including smashing with hammers, I assume).
I remember a director of a firm I used to work at insisting I ensured no one could read data off a drive that died in his laptop - I normally used DBAN but this drive wouldn't spin up. I just took it apart in front of him and shattered the platters with my fingers.
Note: slightly easier with laptop drives.