Computer Forensics Glossary

D

DATA

(1) Distinct pieces of information, usually formatted in a special way. All software is divided into two general categories: data and programs. Programs are collections of instructions for manipulating data.
Data can exist in a variety of forms -- as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind. Strictly speaking, data is the plural of datum, a single piece of information. In practice, however, people use data as both the singular and plural form of the word.
(2) The term data is often used to distinguish binary machine-readable information from textual human-readable information. For example, some applications make a distinction between data files (files that contain binary data) and text files (files that contain ASCII data).
(3) In database management systems, data files are the files that store the database information, whereas other files, such as index files and data dictionaries, store administrative information, known as metadata. - Webopedia

Dbf

A file extension for a dBASE database file.
DBX
Database (multiple programs)
Microsoft Outlook Express E-mail Folder

Deleted Files

This referes to a file state in which the area that a particular file occupies is available to be overwritten by the operating system as part of routine operation.  If a subject knows there are incriminating files on the computer, he or she may delete them in an effort to eliminate the evidence. Many computer users think that this actually eliminates the information. However, depending on how the files are deleted, in many instances a forensic examiner is able to recover all or part of the original data.(2) 

Denial Of Service Attack (DoS)

This is an attempt to make a computer resource unavailable to its intended users. Although the means to, motives for and targets of a DoS attack may vary, it generally comprises the concerted, malevolent efforts of a person or persons to prevent an Internet site or service from functioning efficiently or at all, temporarily or indefinitely. 

Desktop

In graphical computing, a desktop environment (DE, sometimes desktop manager) offers a graphical user interface (GUI) to the computer. The name is derived from the desktop metaphor used by most of these interfaces, as opposed to the earlier, textual command line interfaces (CLI). A DE typically provides icons, windows, toolbars, folders, wallpapers, and abilities like drag and drop. As a whole, the particularities of design and function of a desktop environment endow it with a distinctive look and feel.

Dictionary Attack

This is a technique for defeating a cipher or authentication mechanism by trying to determine its decryption key or passphrase by searching a large number of possibilities. In contrast with a brute force attack, where all possibilities are searched through exhaustively, a dictionary attack only tries possibilities which are most likely to succeed, typically derived from a list of words in a dictionary. Generally, dictionary attacks succeed because many people have a tendency to choose passwords which are short (7 characters or less), single words in a dictionary, or are simple variations that are easy to predict, such as appending a single digit to a word 

Digital

Digital is a system that uses discrete values (often electrical voltages), representing numbers or non-numeric symbols such as letters or icons, for input, processing, transmission, storage, or display, rather than a continuous spectrum of values (ie, as in an analog system).  The distinction between "digital" and "analog" can refer to method of input, data storage and transfer, or the internal working of a device. The word comes from the same source as the word digit and digitus: the Latin word for finger (counting on the fingers) as these are used for discrete counting.  The word digital is most commonly used in computing and electronics, especially where real-world information is converted to binary numeric form as in digital audio and digital photography. Such data-carrying signals carry one of two electronic or optical pulses, logic 1 (pulse present) or 0 (pulse absent).

Digital Audio Tape (DAT or R-DAT)

This is a signal recording and playback medium developed by Sony in the mid 1980s. In appearance it is similar to a compact audio cassette, using 4 mm magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As the name suggests the recording is digital rather than analog, DAT converting and recording at higher, equal or lower sampling rates than a CD (48, 44.1 or 32 kHz sampling rate, and 16 bits quantization). If a digital source is copied then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD MiniDisc, both of which use lossy data compression.

Digital Evidence

Information stored or transmitted in binary form that may be relied on in court.(2)

Digital Storage

This is a casually storage or memory refer to computer components, devices and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention.

Directory

Directory is an entity in a file system which contains a group of files and/or other directories. A typical file system may contain thousands (or even hundreds of thousands) of directories. Files are kept organized by storing related files in the same directory. A directory contained inside another directory is called a subdirectory of that directory. Together, the directories form a hierarchy, or tree structure.

Directory Table

Directory Table is a special type of file that represents a directory (nowadays commonly known as a folder). Each file or directory stored within it is represented by a 32-byte entry in the table. Each entry records the name, extension, attributes (archive, directory, hidden, read-only, system and volume), the date and time of creation, the address of the first cluster of the file/directory's data and finally the size of the file/directory. Aside from the Root Directory Table in FAT12 and FAT16 file systems which occupies the special Root Directory Region location, all Directory Tables are stored in the Data Region. The actual number of entries in a directory stored in the Data Region can grow by adding another cluster to the chain in the FAT.

Disk Cache

Disk Cache is the embedded memory in a hard drive acting as a buffer between the computer and the physical hard disk platter that is used for storage. Modern hard disks come with 8 to 32 MiB of such memory.
See also branch (definition 1), directory, tree structure

Disk Copy

Disk Copy was the default utility for handling disk images in System 7 through Mac OS X 10.2 (Usable in System Software 6 as well). In later versions of Mac OS X it has been replaced by DiskImageMounter for mounting the images and Disk Utility for creating them.
 

Disk Drive

A disk drive is a peripheral device used to collect information from. Main implementations are hard disks, floppy disks and optical discs. Nowadays the term disk storage almost exclusively refers to hard disk storage.

Disk driver

device driver, or software driver is a computer program allowing higher-level computer programs to interact with a computer hardware device.  A driver typically communicates with the device through the computer bus or communications subsystem to which the hardware is connected. When a calling program invokes a routine in the driver, the driver issues commands to the device. Once the device sends data back to the driver, the driver may invoke routines in the original calling program. Drivers are hardware-dependent and operating-system-specific. They usually provide the interrupt handling required for any necessary asynchronous time-dependent hardware interface.

Doc

A file extension that identifies document files formatted for a word processor. This is the default file extension for Microsoft Word document files

Disk Operating System (DOS)

DOS (from Disk Operating System) commonly refers to the family of closely related operating systems which dominated the IBM PC compatible market between 1981 and 1995

DIR

Dir is a command used for file and directory listing, specifically in CP/M and the command line interface (CLI) of the DOS operating system. It is analogous to the Unix ls command.  Because it is the primary means of seeing which files and directories are in one or more directories on a disk or other storage medium, the dir command is one of the most basic commands employed by users of the command line interface to MS-DOS and various versions of Windows.[1]

Domain Name System (DNS)

This system associates various sorts of information with so-called domain names; most importantly, it serves as the "phone book" for the Internet by translating human-readable computer hostnames, e.g. en.wikipedia.org, into the IP addresses, e.g. 66.230.200.100, that networking equipment needs for delivering information. It also stores other information such as the list of mail exchange servers that accept email for a given domain. In providing a worldwide keyword-based redirection service, the Domain Name System is an essential component of contemporary Internet use.

DOT

ext.  Microsoft Word Document Template [Buy Office XP at Shop.Microsoft]
Corel Lines-Definition
Bert's Dinosaurs File
Ribbons Molecular Dot Surface (Molecular graphics software)

Download

This is to receive data from a remote or central system, such as a webserver, FTP server, mail server, or other similar systems. A download is any file that is offered for downloading or that has been downloaded.

DSL

DSL is a family of technologies that provide digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, although in recent years, many[attribution needed] have adopted digital subscriber line as a more marketing-friendly term for the most popular version of consumer-ready DSL, ADSL.

Dual boot

Dual booting or dual-booting is the act of installing multiple operating systems on a computer, and being able to choose which one to boot when switching on the computer power. The program which makes dual booting possible is called a boot loader.

Duplicate

An accurate digital reproduction of all data contained on a digital storage device (e.g., hard drive, CD-ROM, flash memory, floppy disk, Zip, Jaz). Maintains contents and attributes (e.g., bit stream, bit copy, and sector dump).(2)