Erasing or overwriting is a process where a software program (loaded from a floppy disk or CD) basically fills up all the sectors (the data blocks on your hard drive that acts as placeholders for any stored information) on a disk with random characters. Each pass or overwrite makes it harder and harder for data to detected or read.
Overwriting is also currently the only method that is guaranteed to allow you reuse the hard drive after sanitization (you gotta love that word right?). Overwriting should destroy data but allow you to operate the drive and reset the partition and reformat it.
Now you will find a bunch of companies selling disk wiping, erasers, overwriters that they say meet the USA DOD (Dept. of Defense) standards. All this means is that an overwriting program will write by using "zeros" in the first pass overwriting and filling up every space on the drive. Then it will use some other random character for another two passes. Other international organizations recommend anything from 5 or 7 passes of random characters.
Erasing Other Magnetic Media: overwriting should also work for any kind of rewritable media like a floppy or Zip disk. Solid state chips found in Flash memory or Smart cards can have full chip erased or "flashed" clean using their respective manufacturers specifications.
Definition: Floppy disks and hard disks can be called magnetic disks that are used to store information, data and programs for use on a computer. Information is converted in concentric tracks that are magnetically etched by a formatting program that arrives with the operating system.
Why Magnetic Fields Affect Disks:
Magnetic charges on tapes or disks have to be spaced apart so that fields do not interfere with each other. The write head creates a strong magnetic field to reorient the magnetic molecules. The closer the read/write head is placed to the surface, the smaller the magnetic field needs to be. If data locations are too close, writing one bit will also affect its neighboring bits. Also, magnetized areas of a tape or disk that are too close will eventually change neighboring areas.
Tips To Secure Your Hardware Donation
Well-intended computer users are oblivious to the dangers that come from improper disposal of computer hardware. It's imperative that the average computer person understands how to prevent these dangers. Here are a few tips on securing and erasing data before you donate.
Traditional Way to erase the Floppy disks and hard disks:
- Using a disk sanitizer such as Disk Wipe, which will overwrite your original data with "gibberish" so it, too, will become indecipherable.
- Encrypt files with software that provides strong encryption to protect sensitive data, including spreadsheets, word docs, and email messages and attachments.
New Way to erase the Floppy disks and hard disks
Demagnetize the hard-drive with the following "degausser tool". This is generally known as "erasure". The process changes the magnetic alignment of your data so that its magnetic domain points elsewhere, making your data indecipherable; similar to how you would dupe a compass.