A lot of computer users will know that when you delete a file, it isn’t actually completely gone from the system and can often be recovered with a simple piece of data recovery software. This fact is especially important if you are giving away or selling an old computer system / hard drive, or just letting someone borrow an external hard drive or even USB stick because the other user could easily recover data you thought was gone, posing a major security risk.
Even a format and reinstall of the operating system in that situation still doesn’t mean all the old data is completely safe from being recovered by others. The same thing applies to external storage media like USB sticks or memory cards, and these are perhaps more important as they are far more likely to change hands than internal devices.
What you can do is make sure that before a hard drive, SSD or USB stick goes to somebody else, temporarily or permanently, any data that you don’t ever want to be read by others or recovered from these devices gets wiped clean and cannot be retrieved. One way is to wipe the free space on the drive meaning only those files currently visible can be viewed. Another way is to completely wipe the drive or partition clean so no data at all is left on it and nothing at all can be recovered. Here’s a selection of tools that can perform this task and wipe a hard drive clean making it more secure before it leaves your possession.
1. Darik’s Boot And Nuke (DBAN)
DBAN is a very well known and respected data wiping tool that runs from a bootable disc and is great for when you want to sanitize more than a single drive or system drive because it can automatically erase all found partitions. Burn the ISO to CD or create a bootable USB stick and boot to DBAN. Press Enter at the prompt to be taken to interactive mode where you choose your settings. If you type autonuke at the prompt, IT WILL ERASE ALL DRIVES WITHOUT CONFIRMATION, so is something you should be very careful with.
In interactive mode you can change the PRNG (Pseudo Random Number Generator) type, the number of rounds to perform each method and the type of wiping method used. There are 6 to choose from ranging from a basic zero fill, to the default 3 pass DOD Short, DOD standard (7 pass), RCMP (8 pass), Gutmann (35 pass) and the recommended PRNG random data fill which the number of passes is determined by the rounds set. DBAN is a powerful tool but could also be dangerous in inexperienced hands, use with care.
The free version of HDShredder is quite limited in functions compared to the paid versions, but can still perform a 1 pass erase on whole hard drives (not partitions). It doesn’t make clear though whether it is a 0 fill or random fill type of method used in the single pass so maybe is not the software to choose if the drive is going to somebody you don’t know.
The good news is the program comes in a portable Windows executable, an IMG floppy image and also an ISO CD/USB image all included in the zip file so you have multiple ways to get the erasing done. A hex viewer is available to inspect the drive for data and multiple drives can be selected at once using the MultiShred tick box. The Windows program works on XP and above.
3. Parted Magic Eraser
Parted Magic with GParted is one of the best Linux bootable CD environments around today for partitioning and erasing hard drives and is also recommended by companies like Corsair for erasing SSD’s. Simply download the Parted Magic ISO and write it to CD or USB and boot from it. These days the Disk Eraser icon is on the desktop, but if yours isn’t it’s found in the Start menu -> System Tools.
In the main window will be options to zero the MBR, drive or partition using different methods, and for multi pass options there’s the NWipe tool which is actually a fork from and very similar to Darik’s wiping tool in DBAN. The Internal Secure Erase method is the most important because it issues the ATA erase command found in the firmware of nearly all drives since 2001. This is more secure than overwriting with 0’s, 1’s or random data using 3rd party tools and is the recommended way to wipe a hard drive or SSD if your drive supports it. Parted Magic is also found on the Hiren’s Boot CD repair disc.
4. CMRR HDDErase
HDDErase was developed by The Center for Magnetic Recording Research (CMRR) and originally sponsored by the National Security Agency. This tool works exclusively by issuing the ATA Secure Erase Command which is a preferred method for SSD’s and HDD’s made since 2001 (bigger than 15GB), and is DOS based meaning it needs to be run from a floppy, CD or bootable USB stick. The ISO can be burned straight out and includes the HDDErase executable or you can manually copy the file to your own DOS distro.
Boot the disc and at the prompt type hdderase, this will start the process and all you need to do is select your drive and follow the prompts to secure erase it. If your drive supports it there may also be an option to perform an Enhanced Secure Erase which will write set patterns instead of zero’s to the drive. Because the erase is performed within the drive itself, this method is considered more secure and thorough than overwriting with a 3rd party utility. HDDErase is also present on the Ultimate Boot CD and Hiren’s Boot CD repair discs.
5. Roadkil’s Disk Wipe
Roadkil has many little useful tools and Disk Wipe is just about as easy and simple to operate as they come. The program is a tiny portable executable of around 50K and can overwrite partitions or physical discs selectable from the drop down menu. Simply select whether you want to blank the drive with zero’s or random data and enter the number of passes in the box, then click the button to erase. Disk Wipe also works on floppy disks and USB pen sticks and is compatible with Windows 95 and above.
Hardwipe has quite a few useful features and in addition to erasing drives or partitions completely, it can also securely erase files, folders and the drive’s remaining free space. Since we last looked at Hardwipe it has gained the welcome addition of an official portable version although the small trade off is you don’t get the right click Explorer context menu options found in the installer version which allows you to wipe selected files, drives or free space at the click of the button. The program has also gained advertising in its main window in the latest release which isn’t too distracting thankfully.
To select a volume click the Wipe drive button on the left and select the drive or partition to sanitize. There are 6 erasing methods; zero fill, random fill (default), GOST R 50739-95 (2 pass), DOD 5220.22-M (3 pass), Schneier (7 pass) and the fully paranoid Gutmann 35 pass method. The erase can be verified and the computer can be shutdown after the wiping completes. Auto throttling could be useful and reduces wiping speed if it detects the computer is being used or there is mouse / keyboard activity. Hardwipe works on Windows XP SP2 and above.
7. Disk Wipe
Disk Wipe is an easy to use and standalone portable utility that works with hard drives, USB sticks and memory cards etc, and is able to erase them using a variety of different methods. The program will also format the drive before wiping because it works faster if it does so, FAT16, FAT32 and NTFS can be chosen. There are 7 erasing types to choose from including the quick zero fill, random fill and GOST 2 pass (1 zero, 1 random) methods, and the slower British HMG, DOD 5220 and Gutmann methods. A View Data option allows you to view the drive to see what data is present in each cluster, Disk Wipe works on Windows XP and above.
8. MiniTool Drive Wipe
MiniTool are the people behind the excellent partition manager Partition Wizard, and another one of their tools is the simple to use Drive wipe. Sadly the program isn’t portable unless you know how to extract it with Universal Extractor, so may be best suited to erasing external USB sticks or hard drives etc.
The program has 2 main options on startup, Wipe Partition or Wipe Disk, and you simply select the volume to wipe using the partition manager style disc layout. There are 5 basic erasing methods available; zero’s or one’s single pass, a zero’s and one’s 2 pass, and the DOD 3 or 7 pass methods. Drive Wipe works on Windows 2000 and above.
Editor’s Note: Anybody wondering why other good sanitizing tools such as CCleaner or Eraser aren’t included here, it’s because they were covered in a similar article about wiping the free space on hard drives which is also well worth reading.
Special Note: There has been much talk on the internet over the years about how many passes and how much sanitizing needs to be done to make the data on a drive irretrievable. The general consensus is that 1 or maybe even 2 passes is about all you really need to wipe a hard drive, 3 at the most, anything above that is pretty much pointless. In this case a random fill is generally preferred to a single 0 or 1 fill. Even the man behind the famous 35 pass method, Peter Gutmann, has said in his paper on the subject, for drives manufactured since around 2001, 2 random passes is the best you can do.
SSD’s are slightly different again and because of the service functions they have such as wear leveling etc, a standard overwrite with a piece of software is not always enough. In this case, running an ATA Secure Erase command included in the firmware of all modern drives is the best solution and takes very little time compared to a full erase. This resets the memory storage cells back to factory condition and wipes the data off, something which is often recommended to also restore performance to slow running SSD drives. Parted Magic’s Eraser and HDDErase both can perform this function.
Another option is encrypting the drive with something like Bitlocker or Truecrypt before a 1 pass or secure erase. This way, in the highly unlikely event anything is left that is recoverable, it’s encrypted anyway. Of course, you’re welcome to run as many passes to sanitize your drive as you wish or feel comfortable with, but in all reality, there appears to be very little to be gained running any more than 1 or 2 passes.