Destroy Confidential Data
Mac Tip #231/22-February-2006

A friend cleaning up her office found an old treasure trove of floppy discs containing confidential information from clients. She wanted to throw the discs away, but needed to be sure that if anyone were to find them they would not be able to retrieve any of the information.

You may have a similar situation with CDs or DVDs or perhaps a hard drive or even a memory stick or memory card, or in fact anything you can put into a computer and save information to.

My friend asked about using a magnet to scramble the floppies or perhaps using an older Mac with a floppy drive to erase them all, but I said there was a better way.

If you want to be quite sure no-one can retrieve the information from an old floppy or other data store destroy it: physically.

For floppies get a sturdy pair of scissors and maybe a blunt knife and a rubbish bin. A floppy is made up of a plastic case which holds a flat disc of the kind of tape a video tape is made of. Either bend and twist the plastic case on the floppy until it opens or pry it open with the knife. Now use the scissors to cut the actual disc into pieces. If you have strong enough scissors you may be able to cut through both the case and the disc at the same time.

With other media such as CDs and DVDs wrap each one inside a towel and bend it in half until it snaps. My experience is that it will shatter into smaller fragments — the towel catches the shards and protects your hands. Again, sturdy scissors may do a good job.

For a hard drive removed from a computer locate the screws that hold the case together and take out the physical platter(s). Smash or severely scratch them.

Memory sticks and the like can probably be reformatted and used for other purposes but if for some reason you will be throwing it away then use a hammer or something else to physically smash it up.

I believe it’s possible to buy shredders that handle CDs and DVDs, so if you often need to destroy them then check your local office supplies store. It seems they may also be able to shred floppies.

Next time I’ll write about securely erasing data without destroying the medium.