Shredding hard disk drives is the most common data destruction methods and is used by intelligence agencies to permanently destroy sensitive and classified data. How would a cyber-criminal take a pile of shredded hard drive and rebuild the data? Well it might be easier than you think. However the ordinary user shouldn’t be too concerned though.

Hard drives are often shredded to a defined size – 4mm, 3mm or 2mm. A typical hard drive will produce hundreds, if not thousands of mangled pieces. Whilst there is absolutely no way this would ever be reconstructed, it may just be possible to read parts of the data using microscopes.

The platters on a high density drive may well contain a significant amount of information in a single 4mm shred. By identifying the binary source code using very high magnification microscopes a raw image can be built of the data on that individual shred. Put all these together and you can start to rebuild the data.

A binary region on a hard drive platter can be anything from 250 nanometres wide and less. This equates to 100 billion bits per square inch of hard drive platter area. If it was possible to rebuild the data from a shredded hard drive, the cyber-criminal would be kept bust for about twenty years! Furthermore, if the targeted hard drive is shredded and mixed with other hard drives, it becomes impossible to identify all the pieces required.

If you are storing ‘top secret’ data maybe take heed. Otherwise the reality of recovering data from a shredded hard drive remains the stuff of sci-fi movies!