Glossary

An IP multi-cast is a method of sending packets of data to a group of receivers in a single transmission. This method is often used to stream media applications on the Internet and private networks.

See also: Multi-Cast

Multi-homed is any computer host that has multiple IP addresses to connected networks. A multi-homed host is physically connected to multiple data links that can be on the same or different networks. Multihoming is commonly used in Web management for load balancing, redundancy, and disaster recovery.

 

See also: Multi-Homed

The National Institute of Standards and Technology (NIST) is a non-regulatory federal agency within the U.S. Department of Commerce. NIST’s mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

See also: NIST 

A Null session is also known as Anonymous Logon. It is a method that allows an anonymous user to retrieve information such as user names and share this over the network, or connect without authentication. Null sessions are one of the most commonly used methods for network exploration employed by “hackers.” A null session connection allows you to connect to a remote machine without using a user name or password. Instead, you are given anonymous or guest access.

See also: Null Session

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, and proceeding to the bottom layer, over the channel to the next station and back up the hierarchy. The OSI model takes the task of internetworking and divides that up into what is referred to as a vertical stack that consists of the following layers.

1. Physical (Layer 1) – This layer conveys the bit stream, electrical impulse, light, or radio signal through the network at the electrical and mechanical level. Fast Ethernet, RS232, and ATM are protocols with physical layer components.

2. Data Link (Layer 2) – At this layer, data packets are encoded and decoded into bits. The data link layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer.

3. Network (Layer 3) – This layer provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node.

4. Transport (Layer 4) – This layer provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer.

5. Session (Layer 5) – This layer establishes, manages and terminates connections between applications.

6. Presentation (Layer 6) – This layer provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa.

7. Application (Layer 7) – This layer supports application and end-user processes. This layer provides application services for file transfers, e-mail, and other network software services. Telnet and FTP are applications that exist entirely in the application level.

See aloso OSI

A packet is a unit of data that is routed between an origin and a destination on the Internet or any other packet-switched network. When any file (such as e-mail message, HTML file, Graphics Interchange Format file, Uniform Resource Locator request) is sent from one place to another, the Transmission Control Protocol (TCP) layer of TCP/IP divides the file into smaller chunks ideal for routing.

Password Authentication Protocol (PAP) is the most basic form of authentication in which a user’s name and password are transmitted over a network and compared to a table of name-password pairs. The basic authentication feature built into the HTTP protocol uses PAP.

Password cracking is the process of trying to guess or crack passwords to gain access to a computer system or network. Crackers generally use a variety of tools, scripts, or software to crack a system password. Password cracks work by comparing every encrypted dictionary word against the entries in system password file until a match is found.

Password sniffing is a technique used to gain knowledge of passwords that involves monitoring traffic on a network to pull out information. There are several softwares available for automatic password sniffing.

Sniffing attack or a sniffer attack, in context of network security, corresponds to theft or interception of data by capturing the network traffic using a sniffer (an application aimed at capturing network packets). When data is transmitted across networks, if the data packets are not encrypted, the data within the network packet can be read using a sniffer. Using a sniffer application, an attacker can analyze the network and gain information to eventually cause the network to crash or to become corrupted, or read the communications happening across the network.

See also: Sniffing Attack

A patch is a piece of software designed and created to update a computer program or its supporting data, to fix or improve it. This includes fixing security vulnerabilities and other bugs, usually called bug fixes. Each patch is created to improve the usability and/or performance of the system or application.

Penetration is defined as gaining unauthorized logical access to sensitive data by evading a system’s protections.

Pharming is defined as a cyber attack that is intended to redirect a website’s traffic to a masquerading website, which may be a fake one. Pharming is achieved by corrupting a DNS server on the Internet and steering a URL to the masked website’s IP. Generally all users use a URL like www.worldbank.com instead of the real IP (192.86.99.140) of the website. The URL can be redirected to send traffic to the IP of the pseudo website by substituting the pointers on a DNS server. The transactions can be imitated and information like login credentials can be gathered at the pseudo site. Using the information gathered, the attacker can access the real site and conduct transactions using the credentials of a valid user.

See also: Pharming 

Phishing is an attempt to acquire sensitive information such as usernames, passwords, and credit card details by impersonating as a trustworthy entity. Phishing emails may contain links to websites that are infected with malware. Phishing is typically carried out by email spoofing or instant messaging, and it often directs users to enter details at a fake website whose look and feel are almost identical to the legitimate one.

See also: Phishing

A ping of death is an attack that involves sending a distorted or otherwise malicious ping to a computer with the intent of overflowing the input buffers of the destination machine and causing it to crash. A ping of death is fragmented into groups of 8 octets before transmission.

See also: Ping of Death

Plaintext is the most portable format and is supported by almost every application. In cryptography, plaintext refers to any message that is not encrypted.

Poison reverse is a method where the gateway node communicates its neighbour gateways that one of the gateways is no longer connected. The notifying gateway sets the number of hops to the unconnected gateway to a number that indicates “infinite”. In effect, advertising the fact that there routes are not reachable.

See also: Poison Reverse

Promiscuous mode allows a network device to intercept and read each network packet that reaches in its entirety. This is used by network administrators to diagnose network problems, but also by unsavoury characters who are trying to eavesdrop on network traffic (which might contain passwords or other information).

See also: Promiscuous Mode

A proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A proxy server is associated with or part of a gateway server that separates the enterprise network from the outside network and a firewall server that protects the enterprise network from outside intrusion. Most proxies are web proxies, facilitating access to content on the World Wide Web and providing anonymity.

A Public Key is the publicly-disclosed component of a pair of cryptographic keys used for asymmetric cryptography.