Did you know that formatting a hard drive doesn’t actually delete the data stored on it? Recovering data after a hard drive has been formatted is actually quite simple.
When formatting a drive, the tool you use simply deletes the old partition, then creates a new one. The operating system can no longer read the data that the drive contained, but the data still exists.
When selling an old machine, or HDD, or even if you’re just looking to dispose of it, securely erasing everything on your hard drive is very important. But how do you do that?
1. Software (DBAN)
Darik’s Boot And Nuke, or DBAN as many people know it, is a free bootable tool that allows you to securely wipe all of the data on your hard drive to government standards.
DBAN is a command line tool, but is very simple to use. It works by systematically replacing all of the data on your hard drive with a random sequence of gibberish. This renders the old data on your drive completely destroyed and is almost impossible to recover from.
You can use DBAN in a number of different ways, but the “autonuke” method is the easiest. Autonuke is a three pass wipe which results in your data being destroyed to a DoD standard.
How to Use DBAN
Download the DBAN ISO from their website, then create a bootable USB stick. Boot your machine using your DBAN USB stick, at the main prompt enter the command autonuke and press enter.
DBAN will then start to wipe your drive automatically, carrying out three passes so that it overwrites your data with gibberish three times. This process can take many hours to complete depending on the size of your hard drive, so it’s probably best to leave the process running overnight.
Once all three passes have completed, the data on your drive will be completely erased and unrecoverable. You can thenreinstall your operating system if needed.
If you want to fully automate the process and software isn’t your thing, you could always opt for a hard drive eraser. They’re not cheap, costing around $200. But they are very useful, especially if you have a number of drives to erase.
Devices like the Startech Drive Eraser (UK) and the WiebeTech Drive eRazer Ultra (UK) are great and they make the process of erasing your data very simple. Just dock your drive and press a button; the eraser does the rest.
Most hardware drive erasers also allow you to print a receipt. So if you are selling that old machine, you can prove to the new owner that the drive has been securely erased.
3. Break and Replace
If you’re disposing of an old computer after buying a new one, you could simply destroy the old hard drive. Hammering a few large nails through the drive at specific points is a great way of ensuring that the drive is completely useless and that your data is safe.
There’s a few simple tools you need to destroy your drive:
- A hammer.
- Three large nails (4–6 inches would be fine).
- A small block of wood.
- Some safetly glasses.
Place your hard drive on top of your block of wood — after all, you don’t want to nail your hard drive to the floor! Take your first nail and hammer it through the drive at the spot marked by the red circle above.
“Why that spot?” I hear you cry. Driving a nail through that part of the drive will not only destroy the hard drive platters, it will also destroy the read/write heads. Rendering the drive, and the data it contains completely useless.
You could hammer two more nails where the yellow dots are, this will further ensure that the platters within the hard drive are completely ruined and that your data is safe.
This approach is also applicable if you are selling your old machine, rather than disposing of it. Hard drives today are relatively cheap, so you could destroy the hard drive and put a new one in the computer you intend to sell.
If you want to save a few bucks on the new drive, you could buy one reconditioned, from somewhere like eBay.
4. Full Disk Encryption
Ok, you got me. Full disk encryption isn’t really a way of erasing the data on your hard drive. But it is a great way of ensuring your data cannot be read, even if you only format the hard drive when you come to get rid of it.
Encryption works by scrambling all of the data on your drive using extremely complex mathematics. Encrypting a drive makes it almost impossible for prying eyes to access your data, so it practically negates the need for erasing your data.
If you’re unlucky enough to unwittingly sell your computer to a hacker, having an encrypted drive will mean that unless the hacker is straight from the set of Mr. Robot, your data is going to be safe.
Having said that, I would still recommend you use a tool like DBAN to erase your data — it’s always best to be safe than sorry.
Do You Even Erase?
Computer security is everyone’s responsibility. With so many of us turning to computers for things like online banking, budgeting, or even just social media, it’s more important than ever to ensure the data you share with people limited. Even if you share it by accident.
You wouldn’t give your computer password to a stranger, so don’t hand over all of your personal data through lack of diligence. If you’re selling or disposing of an old machine, make sure your data is completely destroyed.
Do you have a different way of securely erasing your data? If so, please tell us about it in the comments below.