Methods for Hard Drive/Disk Destruction
By DON CIO Privacy Team - Published, August 5, 2010
The following guidelines are provided for the proper destruction of Department of the Navy hard drives.
Physical alteration of the disk media and disk heads of a hard drive makes it more difficult to recover data from the media. To deny keyboard and simple laboratory data recovery techniques, the disk heads should be prevented from flying over the spinning disk. Significant media damage reduces the effectiveness of laboratory attack.
- Physical techniques. The least expensive physical techniques should generate surface deformations in excess of 0.001 inch and preclude normal reading through a disk head. This is sufficient to render attacks planned to recover typical CUI prohibitively costly. Physical techniques include:
Thermal destruction techniques. Thermal destruction will not only deform the magnetic media but also purge the data contained on the media.
- Bending. Bend the disk platters to an internal angle of at least 5 degrees. An abrupt bend is preferred.
- Drilling. Drill holes through platters. Drilling should produce holes greater than 0.25 inch. The outer tracks and most of the remaining tracks should be penetrated.
- Cutting. Cuts should penetrate all tracks of the disk surface. Cuts may be accomplished by physical or thermal means.
- Shredding. Shred to a chip size less than 1.5 inches. Shredding circuit boards to a chip size less than 0.5 inches will also likely damage the flash memory.
- Incineration or smelting. Heat to a temperature where the substrate melts (aluminum or titanium alloys) or fractures (glass and ceramics).