J-P

Jaz drive

A true, replaceable hard disk. Each Jaz cartridge is basically a hard disk, with several platters contained in a hard, plastic case.

key logger

Device that intercepts, records, and stores everything that the user types on the keyboard into a file. This includes all keystrokes including passwords.

KISS method

KISS stands for 'Keep It Simple, Stupid' and is an acronym that reminds us to avoid making things overly complex.

known plaintext attack

An attack to decrypt a file characterized by comparing known plaintext to the resulting ciphertext .

logic bomb

A virus or other program that is created to execute when a certain event occurs or a period of time goes by. For example, a programmer might create a logic bomb to delete all his code from the server on a future date, most likely after he has left the company.

malware

Another name for malicious code. This includes viruses, logic bombs , and worms.

Message Digest 5 (MD5)

A method of verifying data integrity that is more reliable than checksum. MD5 is a one-way hash function, meaning that it takes a message and converts it into a fixed string of digits, which is then used to verify that the message hasn't been altered .

metadata

A data component that describes the data. In other words, it's data about data.

modem

A shortened version of the words modulator -demodulator. A modem is used to send digital data over a phone line. The sending modem converts data into a signal that is compatible with the phone line, and the receiving modem then converts the signal back into digital data.

Netstat

A utility that displays the active port connections on which the computer is listening.

Network File System (NFS)

Provides remote access to shared filesystems across networks. The primary function of NFS is to mount directories to other computers. These directories can then be accessed as though they were local.

New Technology File System (NTFS)

A filesystem supported by Windows NT and higher Windows operating systems.

operating system

Acts as a director and interpreter between the user and all the software and hardware on the computer.

packets

Unit of information routed between an origin and a destination. A file is divided into efficient- size units for routing.

passcode

A character string used to authenticate a user ID to perform some function, such as encryption key management.

password

A string of characters used to authenticate a user by comparing the value to a stored value that is associated with a specific user ID.

password cracking

Attempting to discover a password by trying multiple options, continuing until a successful match is found.

PC

A personal computer intended for generic use by an individual. PCs were originally known as microcomputers because they were built on a smaller scale than the large systems most businesses used.

personal digital assistant (PDA)

A tightly integrated handheld device that combines computing, Internet, and networking components . A PDA can use flash memory instead of a hard drive for storage.

plaintext

An unencrypted message.

port scanner

A program that attempts to connect to a list of computer ports or a range of IP addresses.

private key algorithm

An encryption algorithm that uses the same key to encrypt and decrypt.

protocol

A set of rules and conventions that governs how computers exchange information over the network medium.

public key algorithm

An encryption algorithm that uses one key to encrypt plaintext and another key to decrypt ciphertext.