An attack on a computer system or network that causes a loss of service to users by consuming the bandwidth of the network or overloading the processor and memory of the computer system.
DHCP (Dynamic Host Configuration Protocol)
This protocol is used by service providers and network equipment to automatically assign random IP addresses from a pool rather than assigning permanent IP addresses to users.
dictionary attack
Password-cracking attempts that successively tries possibilities that are most likely to succeed, typically derived from a list of words in a dictionary. Generally, dictionary attacks succeed because most people have a tendency to choose passwords that are easy to remember.
distributed denial-of-service (DDoS) attack
Using hundreds or thousands of computers that have been taken over (see bot army) to conduct a DoS attack on a corporation, government entity, or website service with the intent to cause severe service disruption or complete failure.
downlink
The connection and information flow from the service provider to your computer.
drive-by download
The act of prompting the user to download a program while browsing the Internet without the user ever requesting installation of the program in the first place.
DSL (digital subscriber line)
A high-speed Internet connection that uses unused frequencies on phone lines to deliver very high data rates with the use of a specialized modem.
DVD (digital video disc)
An optical storage disc and media format that can be used for data storage, including for movies with high video and sound quality.
dynamic IP address
Having an IP address assigned by a device in the Internet service provider's network, which can change each time an address is requested. Often referred to as DHCP, which is the name of the protocol that specifies the rules for allocating IP addresses in this manner.
