Disposition of Computer Hard Drives
Attachment 3
Definitions

Clearing	Rendering stored information unrecoverable unless special utility software or techniques are used.
Coercivity	Defines the magnetic field necessary to reduce a magnetically saturated material's magnetization to zero. Coercivity strength of an applied magnetic field determines which type of degausser may be applied to a particular type of magnetic material. Demagnetizing the magnetic material of data storage media removes data remanence.
Degaussing	Degaussing (i.e., demagnetizing) is a procedure that reduces the magnetic flux to virtual zero by applying a reverse magnetizing field. Properly applied, degaussing renders any previously stored data on magnetic media unreadable and may be used as a method of sanitization.
Erasing	An ambiguous term which can refer to purging, clearing, or removing file allocation.
Keyboard attack	Extracting information from data storage media by executing software utilities, keystrokes, or other system resource executed from a keyboard. For example, disk and file recovery utilities and memory scavenging procedures can be used to carry out keyboard attacks.
Laboratory attack	Using sophisticated signal recovery equipment in a laboratory environment to recover stored information from data storage media.
Media	Short for storage media. Physical objects on which data can be stored, such as hard drives, floppy disks, CD-ROMs, and tapes.
Memory Scavenging	Searching through data storage to collect residue thereby acquiring data. Data may be stored on records, blocks, pages, segments, files, directories, words, bytes, fields, or peripheral devices, such as printers or video displays.
Overwriting	Process of writing patterns of data on top of the data stored on a magnetic medium.
Oersted	A unit of magnetic field strength.
Remanence	Residual information remaining on data storage-media after clearing.
Sanitize	To expunge data from storage media (e.g., diskettes, CD-ROMs, and tapes) so that data recovery is impossible. Sanitizing includes overwriting, degaussing and destruction. Clearing data does not constitute sanitizing.
User	The state organization with effective ownership or control of a hard drive, not an individual using a computer.