Optical media refers to data storage devices that digitally write and read data via a laser diode. The technology was developed in the late 1950s, but didn’t become widely used until the introduction of Compact Discs (CDs) and Digital Video Discs (DVDs) in the 1980s and 1990s and more recently Blu-Ray Discs.
Methods of Destruction
There are three proven techniques for destroying optical media. Disintegration Shredding Declassifying or Grinding
NSA Destruction Requirements for Classified Optical Media
The NSA Regulation for optical media is NSA/CSS 04-02. It states that discs be reduced to a waste particle no larger than 2.2mm x 4mm. The NSA publishes a list of Evaluated Products that comply with this specification.
Disintegration uses proven rotary knife mill technology to cut discs until the particles are so small that they cannot be reconstructed or otherwise accessed.
Shredding uses dedicated shredders that function much the same way paper shredders do. The difference is that optical media shredders are equipped to deal specifically with plastic, have modified feed openings to prevent “flyback” and special bins to eliminate static build up that typically occurs.
Declassifying uses abrasives to grind the data bearing surface from a disc turning it into dust. This works well for CDs that store data on the external surface of the disc. It can also work for DVDs, but since data on DVDs is contained between two disc layers sandwiched together, discs must be split apart and both halves must be declassified.
Choosing the Best Device for Your Needs
Usually the main criteria to determine the appropriate optical media destroyer is volume. However, other factors such as portability, no power operation, or the ability to destroy other media could be equally important. If volume is low, or portability/no power required operation is a must, a declassifier (grinder) is a good choice. These devices reduce the data layer to 250 microns (recommended by NIST 800-88) leaving only a polycarbonate disc suitable for recycling. If volume is high (hundreds or thousands of discs at a time), a shredder is appropriate. If volume is high and/or you need the ability to destroy other media such as USB drives, smart phones etc, choose a disintegrator or mixed media destroyer.