Acknowledgement. Packet or frame type usually sent upon successful receipt of data.
Asymmetric Digital Subscriber Line. Technology used on telephone lines to provide home Internet access.
Advanced Encryption Standard. Symmetric key cipher. Recommended for use.
Address Resolution Protocol. Maps IP addresses to MAC addresses.
American National Standards Institute. Standards organisation.
Access Point. Device in wireless LAN that bridges wired and wireless segments.
American Standard Code for Information Interchange. Format for mapping English characters to 7 bit values.
Asynchronous Transfer Mode. Wired technology used in core and access networks.
Border Gateway Protocol. Exterior routing protocol for exchanging information between autonomous systems.
Bootstrap Protocol. Used for automatically configuring computers upon boot. Replaced by DHCP.
Berkeley Software Distribution. The original open source variant of Unix, now a popular Linux alternative for servers.
Basic Service Set Identifier. Unique to a wireless LAN AP; normally the AP MAC address.
Certificate Authority. Entity for signing and issuing certificates in public key cryptographic systems.
Cipher Block Chaining. Mode of operation used to allow symmetric block ciphers to encrypt data larger than a block size.
Command Line Interface. User interface to a computer that involves typing text based commands.
Central Processing Unit. The “brains” of a computer.
Cross Site Request Forgery. Web application attack.
Computer Science. Field of study.
Cascading Style Sheets. Defines formatting of content in HTML.
Counter mode. Mode of operation used to allow symmetric block ciphers to encrypt data larger than a block size
Clear To Send. Wireless LAN control from sent in response to RTS.
Concurrent Versions System. Version control software.
Data Encryption Standard. Symmetric key cipher. Not recommended for use.
Distributed Denial of Service. DoS attack coming from many computers.
Diffie-Hellman. Public key cryptography algorithm, primarily for sharing secrets.
Dynamic Host Configuration Protocol. Used for automatically configuring network interfaces of computers in a LAN.
Diffie-Hellman Key Exchange. Public key cryptography algorithm, primarily for sharing secrets.
Domain Name System. Maps human friendly domain names to computer readable IP addresses.
Denial of Service. Attack on server or network the prevents normal users from access the service.
Electronic Code Book. Mode of operation used to allow symmetric block ciphers to encrypt data larger than a block size.
Extended Service Set Identifier. Name given to wireless LAN network; multiple APs may be in the same network.
File Transfer Protocol. Application layer protocol for transferring files between client and server. Uses TCP.
Free Software Foundation. Organisation that promotes the use of free (as in freedom), open source software.
Graphical User Interface. User interface to a computer that involves windows, mouse, buttons etc.
GNU’s Not Unix. A free operating system, using free, open source software. Often combined with Linux kernel to produce GNU/Linux.
Hash-based MAC. Message authentication code function that uses existing hash algorithms. That is, converts hash functions into MAC functions.
HyperText Markup Language. Language for defining how content is displayed in a web browser.
HyperText Transfer Protocol. Application layer protocol for transferring web pages from server to client. Uses TCP.
HTTP Secure. HTTP on top of SSL/TLS, to provide secure web browsing.
Internet Assigned Numbers Authority. Organisation that defines the use of Internet numbers such as ports and protocol numbers.
Internet Control Message Protocol. Protocol for testing and diagnostics in the Internet. Used by ping.
Integrated Development Environment. Software application used for developing, testing and debugging software.
Institute of Electrical and Electronic Engineers. Organisation that defines electrical, communications and computer standards, including for LANs and WLANs.
Internet Engineering Task Force. Organisation that defines standards for Internet technologies, including IP, TCP and HTTP.
Internet Protocol. Network layer protocol used for internetworking. Core protocol of the Internet. Two versions: IPv4 and IPv6.
Internet Protocol Security. Extensions to IP that include security mechanisms. Optional whan using IPv4.
Internet Security Association and Key Protocol. Security protocol for key exchange.
Internet Service Provider. Organisation that provides Internet access to customers.
Information Technology. Field of study.
Initialisation Vector/Value. Value used to initialise cryptographic algorithms. Often chosen by user similar to a key.
Local Area Network. Network covering usually offices, homes and buildings. Layer 1 and 2 technology.
Linear Congruential Generator. Pseudo random number generator.
Long Term Support. Assigned to selected versions of software, such as Ubuntu operating system, to indicate that version will be supported for a long period than other versions.
Message Authentication Code or Medium Access Control
Message Digest 5 hash function. Cryptographic hash function that is still widely used, but no longer considered secure for many purposes.
Network Address Translation. Technique used in networks to convert private, internal IP addresses into public, external IP addresses.
Network Interface Card. Device in a computer that connects the computer to a network.
Network Time Protocol. Protocol for clients to synchronise their clocks to more accurate time servers.
Operating System. Software that provides services for operating a computer, hiding computers details from applications.
Open Systems Interconnection. Standard for connecting different networks together. No longer widely used by the OSI 7 layer model still referred to.
Open Shortest Path First. Internal routing protocol.
Open Web Application Security Project. Project that keeps track of common attacks on web applications and provides advice on securing apps.
Pluggable Authentication Modules. Linux modules that allow application to use different authentication techniques.
PHP: Hypertext Preprocessor. Programming language primarily used to create dynamic web sites.
Physical Layer. Lowest layer in Internet and OSI layer architectures. Deals with transmitting bits as signals.
Pseudo Random Number Generator. Algorithm for outputting random numbers. Not a true random number generator, but commonly used for convenience.
Pre-Shared Key. Secret cryptographic key that two parties have exchanged in advance.
Random Access Memory. Short term, volatile storage area for computers.
Request For Comment. Type of standard used by IETF. The standards for IP, TCP and DNS are RFCs.
Routing Information Protocol. Internal routing protocol.
Rivest Shamir Adleman cipher. Public key cryptographic cipher used for confidentiality, authentication and digital signatures.
Request To Send. Type of WLAN frame.
Round Trip Time. Time for a message to travel from source to destination and then back to the source.
Secure Copy. Command and protocol for transferring files securely from one computer to another.
Synchronous Digital Hierarchy. Wide area network technology used across cities and countries.
Secure Hash Algorithm. Cryptographic hash algorithm. Different variants including SHA, SHA2 and SHA3.
Simple Mail Transfer Protocol. Application layer protocol for transferring email between computers.
Stateful Packet Inspection. Technique that allows a firewall to make decisions on packets based on past packets in a connection.
Structured Query Language. Language for querying databases.
Secure Shell. Application for remotely logging in to a computer.
Service Set Identifier. Same as a ESSID.
Secure Sockets Layer. Protocol for securing application data that uses TCP for communications. Replaced by TLS but still referred to.
Subversion. Version control system.
Syncrhonise. Type of TCP segment, used during connection establishment phase.
Transmission Control Protocol. Transport layer protocol that provides reliable, connection-oriented data transfer. Used by many applications in the Internet.
Trivial File Transfer Protocol. Application layer protocol for transferring files. Very lightweight, compared to FTP.
Transport Layer Security. Replaced SSL.
The Onion Router. System for private networking, whereby it is very difficult for someone to know who you are communicating with.
Time To Live. Value often given to packets so that after a certain time those packets are discarded/deleted. Usually measures in router hops, rather than seconds.
User Datagram Protocol. Transport layer protocol that provides unreliable, connection-less data transfer. Used by applications that require simplicity and/or fast data transfer. Alterative to TCP.
Uniform Resource Locator. Identifies a resource in the Internet, such as a web page. E.g. http://www.example.com/dir/page.html
Virtual Machine. Software implemtnation of a computer, virtualising the typical hardware components of a computer.
virtnet. Software for quickly deploying Linux based virtual machines in a virtual network.
Virtual Private Network. Technology for private communications from a client to server.
World Wide Web Consortium. Organisation that sets standards for web browsing and applications, such as HTML.
Wide Area Network. Network that covers cities and countries, usually owned by telecom operators or ISPs.
Wireless Fidelity . Marketing name for WLAN.
Wireless Local Area Network. Technology for wireless communications on a LAN.
WiFi Protected Access. Encryption and authentication protocol for WLANs.
Windows Subsystem for Linux. Software that allows command-line based Linux operating systems to run as an application in Windows.
eXtensible Markup Language. Language for defining other languages that define the structure/organisation of content.
Cross Site Scripting. Web application attack.