In spy films the idea of wiping a hard drive usually ends with the drive letting out a puff of smoke as it self-destructs, the reality of wiping a hard drive is not so dramatic.
Yes. Wiping a hard drive essentially means that data is removed and is completely unretrievable. This can be done in such a way that the hard drive can still be reused.
In this article, we look at how to wipe a hard drive without the need for it to self-destruct.
Why would I need to wipe a hard drive?
Maybe you’re a spy on an international mission carrying sensitive data over state lines, or maybe you just want to be sure those bank statements cant be found by anyone else.
As stated previously there is a difference between erasing a hard drive and wiping a hard drive. Erasing a hard drive does not mean that the data is gone forever, wiping does. With that in mind, it is useful to consider the pros and cons. Erasing a hard drive is easy, wiping one is trickier.
Let’s have a look at each.
Wiping – Pros.
- Data is irretrievable.
- The hard drive is reusable.
- Peace of mind that sensitive data is secure.
- Difficult to execute.
- Requires additional software.
- Data cant be recovered if wiped by mistake.
Erasing – Pros.
- Easily done in a few clicks.
- Data is retrievable initially.
- Can be done by any operating system.
- The hard drive is reusable.
- Data can be recovered so is less secure.
- Can be deceptive to the user as having been deleted.
- No peace of mind of security.
The second con there is an interesting one. I have read about hackers who have found sensitive data from recovering hard drives they bought in thrift stores. People assume that emptying the trash on their desktop is enough to protect their files and end up leaving vulnerabilities they had never considered buy donating to goodwill without securing their data first.
In summary, if you need to be confident that the data is irretrievable or if you are disposing of the drive then wipe it. Otherwise, a simple format should have you covered.
How to wipe a hard drive for reuse.
So let’s start by stating here that we have the intention of reusing the drive, how can we go about ensuring the data is completely removed without a trace.
Firstly it’s worth noting how data is stored on a hard drive, in particular an HDD. The data is stored in a binary sequence on a magnetic film coating a disk. The polarity of the segments of this film creates a 1 or a 0, this is binary which is the base code for almost all computing. A head reads the disk on an armature like a record player or CD player. The head can also set the polarity of the individual sections of the magnetic film (byte), this is what we call writing data.
Ok, so you got the basics of the data storage mechanism. Now when you unplug the hard drive all of the polarity data stays put until you plug it in again to be read. The same is true for solid-state drives but the binary is stored in an electric charge.
Wiping Data using disk format.
If you want to wipe all of the data from the drive you will need to reset or change all of the polarity of the drive. This is why you will commonly see people saying a simple format won’t do it. Because a format doesn’t change the polarity it just removes the partition table (reference table for where each bit of data is on the disk.) so that the computer ignores it. This is why if you format a drive by mistake it can be recovered so long as you don’t fill it up again.
If the data isn’t sensitive this will suffice for most people. As you put new data on the disk the old data will be overwritten and become unretrievable and after a while, it will be completely untraceable. You could even speed the process up by copying a large file, say a film, then duplicating it until the disk is full and formating it again. That way if anyone tried to recover data from the drive all they would see is multiple copies of the film. Just make sure it isn’t pirated!
Wiping data using DBAN.
For full guaranteed file destruction then DBAN is the go-to tool. Be advised it can be a pretty complicated task and probably isn’t for someone completely with no tech-savvy.
DBAN (Darik’s Boot and Nuke) Is software that needs to be installed on a bootable disk. You then remove all hard drives that you don’t want to be erased from your computer including your startup disk. Then plug in the disk you have DBAN on and restart the computer with the disk you want to nuke plugged in. Then follow the steps as DBAN does just that.
I won’t go into specific detail here of how to do this but all the resources you need can be found on the DBAN website here.
How to wipe a hard drive that won’t be resued?
Well… I guess if your reading this far you are a spy on an international mission and need to delete sensitive data to stop it from getting into the wrong hands.
Firstly use the technique above using the DBAN tool. You need to be sure that the drive contains nothing before you destroy it.
To destroy a hard disk beyond repair the best bet is crushing it or dismantling it followed by burning the components. Separate any parts that aren’t flammable and discard them responsibly in as many different places as you can.
Then you can sleep soundly knowing that a baddy isn’t going to get your data.
There is some method in the madness here, there are many parts to a hard drive that can give clues as to how when where, and why a disk was used. So if the annihilation of evidence is your desired outcome, splitting the disk into components then destroying them is your best bet.
If you aren’t a spy carrying national secrets then use DBAN and hit it with a hammer a few times and then dispose of it responsibly.
Usually, I finish articles with a reminder to back up your data but seeing as this is about erasing it I guess that doesn’t seem fitting.