How to Securely Destroy Data

Securely erasing data that isn’t needed anymore is so important, and there are a number of methods of doing this.

Whether you’re disposing of a hard drive that is no longer in use, selling it to someone else, or just clearing some free space, you should always delete your data securely. Data can be a goldmine for criminals, whether it’s from a business or personal hard drive. When you delete data from a hard disk drive, it doesn’t take a great deal of skill to recover it. What’s actually deleted is the master file table (MFT) entry; these entries are then marked as free and can be reused. But the actual data – stored as a series of 0s and 1s – is still there, until it is overwritten with new data. This is how data recovery software works, scouring the hard drive to locate binary data and piecing it back together into a salvageable format. Consider the sort of data you store on your hard drive, whether it’s your personal or business computer – would you want it in the hands of a stranger? If you want your data to be truly deleted, you have two options – physical destruction and overwriting.

Physical destruction is pretty self-explanatory, and obviously is only an option when you’re getting rid of a hard drive rather than selling it. You can do this at home using a hammer and screwdriver, making sure the platters are thoroughly smashed. Alternatively, you can hire a company to physically destroy your data. This can be done through a process called degaussing, which involves destroying the platter’s magnetic fields, or shredding, which turns the drive into tiny particles. Importantly, degaussing will no work with SSDs, which don’t store data magnetically, so shredding is the only option here.

The second option – and perhaps the easiest is disk wiping, whereby the drive is written with dummy data. This ensures that the original data cannot be recovered. Darik’s Boot and Nuke (DBAN) is a free tool that can be used to securely overwriting the data on your hard drive. Once you have booted into the DBAN screen, press Enter, which brings up the tool’s Interactive Mode. Here, you can select the drive you want to erase, pressing Space then F10 to initiate the erasure process. Upon completion of the dummy data’s writing, you will get a notification.

Data Recovery