The media run rampant with stories of cracked computer files and corporate espio-nage. So why do people think nothing of leaving electronic versions of sensitive documents on a hard disk drive, readily accessible to anyone who sits down at the computer and types a few commands?
There is a simple, low-cost method to keep your sensitive computer documents confidential. Store them on floppy disks instead of on your hard disk. Then treat those floppies as you would confidential paper documents -- lock them up when you aren't using them. The disadvantages of floppies -- slower operation and lower capacity than hard disks -- are a small price to pay for security and privacy.
After you've moved the sensitive files from your hard disk to the floppies, you should erase them from the hard disk. Simply deleting files doesn't actually remove the data from a hard disk. The information is still there; only a directory entry is changed. To actually erase the data, you need to use a utility program such as PC Tools Deluxe from Central Point Software Inc. for the IBM PC and clones; MacTools Deluxe, also from Central Point; or Symantec Corp.'s SUM II for the Macintosh.
If you don't have access to utility software, then you should change or garble the contents of your sensitive file on the hard disk after you've copied it to a floppy disk. If your program makes a backup file automatically, then you'll want to garble the backup file as well by making an additional change to the saved garbled file and saving it again. Then delete both the file and the backup file. This method isn't as good as a true erasure, but only the most determined snoopers will be able to find your documents.
If you must keep a sensitive file on a hard disk (perhaps because it is too large to fit on a floppy), then you should use an encryption program that scrambles the contents. The three utility programs mentioned above all do encryption.
-- Cary Lu