Miki is our faithful secretary who, despite many excellent qualities, knows very little about acronymns and technology terms. When she hears things like “the TCP sequence in the IP Header” or “how to choose between SSL VPN and PPTP VPN” it just makes her head spin. So Miki has taken the time to put these confusing terms into plain English in the following Glossary. It serves as a Mini-Wiki to help our users understand the technology terms used in our site.
AES (Advanced Encryption Standard): An encryption standard being developed by NIST. Intended to specify an unclassified, publicly-disclosed, symmetric encryption algorithm.
Administrator: A high level user able to access and demand all available resources from a computer.
Algorithm: A set of step-by-step instructions for a problem-solving or computation procedure, especially one that can be implemented by a computer.
Antivirus: Computer programs that attempt to identify, thwart, and eliminate computer viruses and other malicious software (malware). Antivirus software can identify viruses using either the signature of a known virus or by detecing anomalous behavior.
Asymmetric Cryptography: Or public-key cryptography. A modern branch of cryptography in which the algorithms employ a pair of keys (a public key and a private key) and use a different component of the pair for different steps of the algorithm.
Auditing: Auditing is the analysis of assets to ensure such things as policy compliance and proper security.
Authentication: Authentication is the process of confirming the correctness of a claimed identity.
Availability: Availability is the need to ensure that the business purpose of a system can be met and that it is accessible to those who need to use it. See uptime.
Bandwidth: Commonly used to mean the capacity of a communication channel to pass data in a given amount of time. Usually expressed in bits per second (bps) and sometimes in kilobits per second (kbps) or kilobytes per second (KBps).
Bit/Byte: A byte is the fundamental unit of computer storage; the smallest addressable unit in a computer’s architecture. Usually holds one character of information and usually means eight bits. A bit is a “binary digit”; one of two symbols “0” (zero) and “1” (one) that are used to represent binary numbers.
Block Cipher: A block cipher encrypts one block of data at a time.
Broadcast: Broadcasting (network) refers to transmiting a packet that will be received (conceptionally) by every device on the network. In practice, the scope of the broadcast is limited to a broadcast domain. Contrast broadcasting (one-to-any), unicasting (one-to-one), and multicasting (one-to-many in a joined predefined group).
Browser: A client computer program that can retrieve and display information from servers on the World Wide Web (e.g. Windows Explorer, Safari, Firefox, etc.).
CPU (Central Processing Unit): The CPU is the component in a digital computer that interprets instructions and processes data contained in computer programs.
Cache: Pronounced cash; a special high-speed storage mechanism. It can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching.
Certificate-Based Authentication: Certificate-Based Authentication is the use of SSL and certificates to authenticate and encrypt HTTP traffic.
Cipher/Ciphertext: A cryptographic algorithm for encryption and decryption. Ciphertext is the encrypted form of the message being sent.
Client: A system entity that requests services from a Server.
Client program: An application program which provides some service or capability, usually through a network, for a user. The program that you use to receive and send email is an example of a client program; it is providing you, the client, with email service.
Cookie: Data exchanged between an HTTP server and a browser (a client of the server) to store state information on the client side and retrieve it later for server use. When sending data to a client, an HTTP server may send along a cookie, which the client retains after the HTTP connection closes. A server can use this mechanism to maintain persistent client-side state information for HTTP-based applications, retrieving the state information in later connections.
Cryptography: Cyrptography is a discipline of mathematics and computer science concerned with information security and related issues, particularly encryption and authentication. Also known as cryptology.
DES (Data Encryption Standard): A widely-used method of data encryption using a private (secret) key. There are 72,000,000,000,000,000 (72 quadrillion) or more possible encryption keys that can be used. For each given message, the key is chosen at random from among this enormous number of keys. Like other private key cryptographic methods, both the sender and the receiver must know and use the same private key
DNS (Domain Name System): The domain name system (DNS) is the way that Internet domain names are located and translated into Internet Protocol addresses. A domain name is a meaningful and easy-to-remember “handle” for an Internet address.
DSA (Digital Signature Algorithm): An asymmetric cryptographic algorithm that produces a digital signature in the form of a pair of large numbers. The signature is computed using rules and parameters such that the identity of the signer and the integrity of the signed data can be verified
Diffie-Hellman (DH): A key agreement algorithm published in 1976 by Whitfield Diffie and Martin Hellman. Diffie-Hellman does key establishment, not encryption. However, the key that it produces may be used for encryption, for further key management operations, or for any other cryptography.
Email: Electronic mail, or email, lets you communicate with other people on the Internet. Email is a basic Internet service and is by far the most popular.
Encryption: In cryptography, encryption is the process of obscuring information to make it unreadable to anyone without special knowledge.
Expatriate: Or expat. Someone temporarily or permanently residing in a country and culture other than that of their upbringing or legal residence. At PSMail, expat does not mean a person forced to emigrate for political reasons.
Firewall: A logical or physical discontinuity in a network to prevent unauthorized access to data or resources.
HTML (Hypertext Markup Language): The set of markup symbols or codes inserted into a file intended for display on a World Wide Web browser page.
HTTP (Hypertext Transfer Protocol): The protocol in the Internet Protocol (IP) family used to transport hypertext documents across an internet.
Hoax: Hoaxes attempt to trick or defraud users. A hoax could be malicious, instructing users to delete a file necessary to the operating system by claiming it is a virus. It could also be a scam that convinces users to send money or personal information.
Hyperlink: In hypertext or hypermedia, an information object (such as a word, a phrase, or an image; usually highlighted by color or underscoring) that points (indicates how to connect) to related information that is located elsewhere and can be retrieved by activating the link.
IP (Internet Protocol): The method or protocol by which data is sent from one computer to another on the Internet.
IPSEC (Internet Protocol Security): A developing standard for security at the network or packet processing layer of network communication.
Keystroke logger: A tool that captures the keys struck on a keyboard, typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored. There are numerous ways that keystrokes can be logged, including both hardware and software-based methods.
L2TP (Layer 2 Tunneling Protocol): An extension of the Point-to-Point Tunneling Protocol used by an Internet service provider to enable the operation of a virtual private network over the Internet.
MD5: A one way cryptographic hash function.
PGP (Pretty Good Privacy): PGPTM is a trademark of Network Associates, Inc., and refers to a computer program (and related protocols) that uses cryptography to provide data security for electronic mail and other applications on the Internet.
PPTP (Point-to-Point Tunneling Protocol): A protocol (set of communication rules) that allows corporations to extend their own corporate network through private “tunnels” over the public Internet VPN Protocol.
Phishing: The use of e-mails that appear to originate from a trusted source to trick a user into entering personal information at a fake website. Typically the e-mail and the web site look like they are part of a bank the user is doing business with.
RAM (Random Access Memory): RAM refers to data storage formats and equipment that allow the stored data to be accessed in any order, that is, at random, not just in sequence. Usually represented in MegaBytes or GigaBytes.
ROM (Read-Only Memory): ROM is a class of storage media used in computers and other electronic devices. A good example is the CD-ROM where information and data can be read but not written.
RSA (Rivest-Shamir-Adleman): An algorithm for asymmetric cryptography invented in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman.
Removable media: This refers to cartridge and disk-based physical storage devices which can be used to easily move data between computers with physical access. Floppy disks, compact discs, and flash memory cards are all removable media.
SHA1: A one way cryptographic hash function.
SSL (Secure Sockets Layer): A protocol developed by Netscape for transmitting private documents via the Internet. SSL works by using a public key to encrypt data that’s transferred over the SSL connection. TLS is its predecessor.
Secure email: Secure email provides either client-to-server (SMTPS/POP3S/STARTTLS) or client-to-client (S/MIME) security and encryption for email sent over the Internet.
Server: A system entity that provides a service in response to requests from other system entities called clients.
Session: A session is a virtual connection between two hosts on which network traffic is passed.
Session Hijacking: Taking over a session that someone else has established.
Session Key: In the context of symmetric encryption, a key that is temporary or is used for a relatively short period of time. Usually, a session key is used for a defined period of communication between two computers, such as for the duration of a single connection or transaction set, or in an application that protects relatively large amounts of data and, therefore, needs to be re-keyed frequently.
Spam: The abuse of electronic messaging systems to send unsolicited, bulk messages. While the most widely recognized form of spam is e-mail spam, the term is also applied to similar abuses in other media like faxes and instant messaging.
Symmetric Key: A cryptographic key that is used in a symmetric cryptographic algorithm.
TCP/TCP-Handshake: TCP (Transmission Control Protocol) enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent. Ex. Machine A sends a packet with an SYN flag set to Machine B. B acknowledges A’s SYN with a SYN/ACK. A acknowledges B’s SYN/ACK with an ACK.
TLS (Transport Layer Security): A protocol that ensures privacy between communicating applications and their users on the Internet. When a server and client communicate, TLS ensures that no third party may eavesdrop or tamper with any message. TLS is the successor to the Secure Sockets Layer (SSL).
UDP (User Datagram Protocol): An IP based protocol like TCP. Unlike TCP, however, UDP provides very few error recovery services, offering instead a direct way to send and receive datagrams over IP. Although considered unreliable, UDP is used over the Internet for critical information such as DNS or VPN due to its low overhead and quick delivery.
URL (Uniform Resource Locator): The global address of documents and other resources on the World Wide Web. The first part of the address indicates what protocol to use. The second part specifies the IP address or the domain name where the resource is located, followed by directory structure where the resource is. Ex. http://www.example.net/directory/filename.ext
USB (Universal Serial Bus): USB is a serial bus standard for connecting devices. It was designed for computers such as PCs and the Apple Macintosh, but its popularity has caused it to become commonplace on video game consoles, PDAs, portable memory devices, and even devices such as televisions and home stereo equipment.
Uptime: A measure of the time a computer system has been “up” and running. The term came into use to describe the opposite of downtime (times when a system was non-operational). The uptime and reliability of computer and communications facilities is sometimes measured in nines. “Five nines” means 99.999% reliability, which translates to a total downtime of no longer than five minutes per year.
Userland: A program or process developed in this space has the ability to run on a computer without administrator privileges. It is less privileged than the Administrator.
VPN (Virtual Private Network): A restricted-use, logical (i.e., artificial or simulated) computer network that is constructed from the system resources of a relatively public, physical (i.e., real) network (such as the Internet), often by using encryption (located at hosts or gateways), and often by tunneling links of the virtual network across the real network. For example, if a corporation has LANs at several different sites, each connected to the Internet by a firewall, the corporation could create a VPN by (a) using encrypted tunnels to connect from firewall to firewall across the Internet and (b) not allowing any other traffic through the firewalls. A VPN is generally less expensive to build and operate than a dedicated real network, because the virtual network shares the cost of system resources with other users of an otherwise open network.
Virus: A computer virus is a self-replicating computer program that spreads by inserting copies of itself into other executable code or documents. A computer virus behaves in a way similar to a biological virus, which spreads by inserting itself into living cells.
Vulnerability: A flaw or weakness in a system’s design, implementation, or operation and management that could be exploited to violate the system’s security policy.
Webmail: A tool that lets you send and read emails directly from any computer connected to the internet. You basically use your browser such as Internet Explorer, Firefox, Chrome or Safari to access your email. For PSMail users, this is using PSMail’s mail portal website https://mail.psmail.net/
WEP (Wired Equivalent Privacy): A security protocol for wireless local area networks defined in the standard IEEE 802.11b.
Wiretapping: Monitoring and recording data that is flowing between two points in a communication system.
Worm: A computer program that can run independently, can propagate a complete working version of itself onto other hosts on a network, and may consume computer resources destructively (e.g., Melissa Worm).