Part H: "DELETE," "ERASE," and "FORMAT"
Before we discuss how to dispose of classified information, lets take a look at some things which
DON'T work. If you store classified information on a floppy disk or hard disk, there are some
computer commands which seem to erase classified information from the disk, but, in reality, DO NOT
purge information from the media, and DO NOT meet the prerequisites for declassification.
"DEL" (delete) and "ERASE" are MS-DOS (a program which controls the basic operation of a PC)
commands which delete a file from a disk. Word processing programs also have a delete or erase
command. These commands DO NOT actually erase the information! They only remove the file name
from the disk file directory, which is a kind of table of contents for the disk.
"FORMAT" is an MS-DOS command which prepares a disk to receive files. If you format a disk on
which files are stored, only the disk file directory and volume table of contents (VTOC) are blanked
out The directory and VTOC are removed, but he files and all the information have NOT actually been
Part I: "RESTORE"
There are a number of commercially available computer utility programs which can "unerase" deleted
files and can recover files from a formatted disk. Using such software, any deleted or erased file can
be recovered. If you store a SECRET file on a disk and delete or erase that SECRET file or format
that disk, that disk is still SECRET.
Part J: Approved Methods for Purging Computer Media
If "erase" or delete" doesn't purge your computer media, what does? Paragraph 2-21, AR 380-19,
describes the methods for purging which are the ONLY ones approved for use in the U.S. Army.
These methods DO purge all information and DO not meet the prerequisites for declassification.
Volatile Random Access Memory (RAM): Volatile RAM (internal memory chips which do not retain their
data when electrical power is removed) can be purged by overwriting all locations with any character,
or by performing a power off/on cycle (turn the power off, then on, and then off again).
Floppy disks (magnetic): Floppy disks (both 5.25 Inch and 3.5 inch) can be purged by degaussing
with a Type I or Type I degausser. These degaussers are listed in NSA (National Security Agency)
publication, "Information Systems Security Products and Services Catalogue." There are a lot of
degaussers on the market, but you can ONLY use those that are approved by the NSA.
Hard disks (magnetic): Hard disks can be purged by degaussing with a Type I or Type II degausser.
They can also be purged by overwriting all locations as described in Table 2-2, AR 380-19.