Computer data has become so ubiquitous in our everyday lives, that we use it to store even our most sensitive data. Whether they’re personal pictures or videos, or just classified documents, we want our data to be secure at all times.
This also includes situations where we want to get rid of the data so that no one could dig up our fully functional private hard drive in a garbage pile. There are many different ways of destroying data, so we decided to compile some of the more effective and interesting ones.
How Hard Drives Work
Before you can crush the hard drive, you must become the hard drive … or something like that. In other words, to know what forms of destruction would actually completely erase hard disk drive data you must understand how and where exactly that data is stored.
Your data is stored in two places – the hard drive platters, that store all the data you put on your hard drive, and the electronic cache, which holds the most used or just recent data from the platters.
The HDD Platters
Hard disk platters are the main part of any hard disk drive. They store your data, by applying a magnetic charge to microscopic grains of a magnetic material, thus changing their state. For example, when a binary “1” is stored, the write head applies a charge to a magnetic grain on the platter’s surface in order to give it a higher charge, which can later be read back as the binary “1”.
Everything else on top and below that magnetic layer is applied to make the platters lighter and sturdier and to protect the sensitive magnetic layer. There are usually two types of platters – ones where the disk is made out of aluminum, and ones that are made out of glass and other brittle compounds.
So, to destroy data, you have to make sure that pretty much all sectors of the platter are damaged, in order to make the data stored on the microscopic grains unreadable. Since the only real method of reading data from a hard disk is to have it spin, deforming it enough to not have it spin ever again would do the job as well.
The Drive Cache
Computer data doesn’t simply go directly to the write head to get written on the platter, there has to be an integrated controller that would control the writing and reading processes. This is where the drive buffer, A.K.A. the drive cache, comes in since it “tells” the data what spaces on the platter surface are free and “remembers” where certain data is stored. Basically, it controls and optimizes everything your hard drive does.
Not only that, it also saves the most recent and most often used data in its own, tiny DRAM unit. This allows the drive to read and load data much faster, as well as predict what data you will use at one moment. For example, if you start loading one file of a game, the cache may already know that you’ll probably load the rest of them, so it puts the rest of those files within the cache for it to be loaded faster.
Since some file preferences and data might be left in the cache, it’s important to destroy that too. The cache itself is just a circuit board with a couple of chips, so all you have to do here is smash them up for that data to be lost.
1. Wipe the Drive
Use this method if you want the drive to be usable afterward.
Wiping a drive means overwriting any stored data with ones, zeroes, or random combinations of both, making that data unrecoverable. This requires using a 3rd party software tool, like Darik’s Boot And Nuke (DBAN).
When you delete files normally, they don’t disappear from a hard disk drive, but rather become addressed as free space for new data to be written on. Erasing would be the proper term for removing data from existence, which is accomplished by writing over new data in the same position. Since erasing every file you delete would take much longer (because of the overwriting process), and would make the process irreversible, computers usually don’t do it by default.
The main concern here, though, is how effective is the data destruction process, i.e. will no one be able to recover your data. While wiping the drive is only the first thing you do in any scenario of data destruction, for many, it will already be sufficient. Research papers have been created on this subject, with most of them coming to the same conclusion – a couple overwrites of random data will make the original data basically untraceable.
If you have any knowledge about wiping drives, you may have heard about the Gutmann 35 overwrite wipe, where data is overwritten 35 times to avoid potential recovery. However, Gutmann himself has stated that the paper suggesting this was written in the mid-90s, making it unviable in today’s standards. Back then, there were a whole lot of different encoding standards for computers, performed my much more janky and unprecise hardware, making the 35 overwrites necessary to avoid every recovery method out there. However, today there are only a couple encoding methods out there, not that it matters much because HDD read/write heads are precise enough to rewrite all bits on the platters.
After performing a couple overwrites, the wiping process should be done, after which the empty drive will have to be reformatted for it to be usable again. So, all you have to do to completely destroy your hard drive data is wiping that drive with software. But what fun would that be …
Destroy Data Physically
WARNING! Be careful and use the proper protective gear and eyewear when trying to destroy the hard drive. Also, as you will quickly understand, this will make the hard drive unusable.
As we discussed before, your data is stored in the hard drive platters and memory chips. So, if you’re too paranoid about the drive wipe not working, you may want to try a “hardware” approach, rather than a software one. Below are a few more sensible and practical ways of destroying the hard drive itself. Note that wiping the drive beforehand is necessary for maximum security, even if you manage to destroy the drive physically.
2. Smash The Drive Platters and Controller Yourself
The simplest way of solving problems – applying a hammer to them. But don’t waste extra energy smashing the metallic case of the drive.
Unscrew and pry open the drive’s case and other parts of the drive (different ways of unscrewing for different models) in order to remove the platters and microchips. Remove the hard disk platters and the circuit boards, put them on a hard surface, and start smashing them. Wear protective eyewear and gloves (at least), because many drive platters are made out of glass compounds that shatter easily.
Make sure that the drive can’t be put together or bent back into its original form, and you should be done. Collect the smashed parts of the hard drive and take them to the nearest electronics store, which usually has a way of disposing of electronic parts safely.
3. Have an Industrial Shredder Smash the Drive For You
The procedural way of destroying hard drives is throwing them into an industrial shredder, which will turn them into a mush of metal and plastics. Look up any industrial shredders in your area that might be available to rent or just use for a second. Needless to say, nobody’s going to recover anything from a hard drive that has gone through a shredder. Here’s a somewhat satisfying video showing just how interesting it may be:
4. Degauss the Drive To Ruin Its Magnetic Properties
Bits of your information (ones and zeroes) are stored on the hard disk platters in the form of magnetically charged, microscopic areas of material. These areas are charged via tiny magnetic fields, generated by the read/write head.
These charges are very local, which is why they don’t require a lot of energy or a super-strong field. So, weak magnetic fields around the platters won’t destroy the data on it. This is where the degausser comes in – it produces such a strong magnetic field, that all the magnetized grains in the platter surface will change to the same alignment. If you don’t have any rentable degaussers around your house or don’t want to pay $5’000 for an entire degausser unit, you can buy a smaller degausser wand, that will erase your data after moving it around near the drive platters for just around $500. One of those big, industrial magnets (like the one in scrap heaps) will do the job as well.
You might ask, how is this different from simply wiping the drive and setting all bit values to “0” or “1”? The difference is that the software wipe tool doesn’t touch the drive’s firmware, which is an integral part of what makes a hard drive function at all. Firmware provides basic functions and connection to other devices, as well as a basis for formatting, so without it, a hard drive is just a bunch of fancy metal and plastic.
5. Use a Sanding Machine or Sandblaster
If you don’t want to break the disk platters themselves, or don’t have degaussing tools nearby, you can try to remove the magnetic layer altogether. Using just sandpaper or a metal file will take a long time since the magnetic layer of the platters is rather thick and hard to get rid of efficiently. Instead, have a machine do the work for you, Just be careful, as powerful automated tools may heat up the platter or cause other potential hazards, wear protective gear!
If you have a sandblaster lying around, try using that, which is crossing over into realms of overkill, but might be more fun. Other hardware tools, like drills, might do the trick, but most other options would require more work. Again, safety first!
What Not To Do
WARNING! We don’t recommend any of the methods mentioned further!
The previously mentioned methods are rather safe and can be performed without any major safety hazards (if you use personal protection procedures, of course). However, many times on the internet, you might run into suggestions involving burning the drive, throwing it into acid, microwaving it, and much more. Any thermal or chemical reaction involving hard drive parts will cause safety hazards, ranging from obnoxious fumes to shattering and exploding of certain parts! This is why you should not attempt to burn a drive in any shape or form, to try to melt it in acid etc.
None of these dangerous methods accomplish anything more than a hammer or a bit of sanding. This is why you should stick to the simple methods discussed before and not try to get on the front page of youtube with a “3’000 degree hard drive” video.
All in all, simply wiping a drive will keep your data safe. If you’re still not sure about the safety, degauss the drive, then sand it, then smash it up. If you don’t want to destroy it manually, throw it in a shredder. No one in a million years could uncover anything from that. Good luck in your HDD destroying endeavors, and stay safe!