Tuesday, 28 June, 2005

How do you securely destroy a CD or DVD?

Related to the previous note, how the heck do I securely destroy a CD or DVD?  I know I can make it unreadable to a standard drive by shattering it or popping it in the microwave for about two seconds.  But that doesn't really affect the bits that are written to the media.  Could somebody melt the plastic cover off the CD and read the raw media using techniques similar to those used to reconstruct information from damaged hard drives?  Seems to me the best way would be to shred the media.

Several companies make devices that purport to make your data unreadable.  Aleratec makes a DVD/CD shredder that doesn't actually shred the media in the normal sense.  It simply impresses a waffle pattern on the plastic covering, making the CD unreadable by any normal means.  That would stop the average dumpster diver from stealing your information, but it wouldn't deter somebody who is more motivated.

Many companies make devices that actually shred the media in much the same way that a paper shredder shreds paper.  In fact, some paper shredders will shred CDs, DVDs, and diskettes.  Provided the resulting pieces are small enough, it would be very difficult (but not impossible) for even the most motivated black hat to obtain any useful data.  This option gives the most bang for the buck.

As with hard drives, the only sure way to destroy the data would be to melt the media into so much slag.  I suspect a machine to do that would be way too expensive unless you really don't want the government to have any chance at reconstructing your data.  But if they were willing to go to that extreme, they'd probably be better off getting a warrant and seizing your computer.

I think I'll invest in a new paper shredder.