User guide

Glossary
Multi-Tech Systems, Inc. RouteFinder RF850/860 User Guide (PN S000400E) 177
Authentication Header (AH) – A provision of IPSec that adds a digital signature to an IP packet. The digital
signature is created through a key-controlled "hashing" of each packet, providing user authentication, and
system integrity.
Broadcast – The address that a computer refers to if it wants to address all the computers of a network.
Example: for a network with the IP address 212.6.145.0 and a net mask 225.225.225.240, a broadcast would be
the address 212.6.145.15.
CSS (Cascading Style Sheets) – HTML was intended to mark up only a Web page's structure, but not its on-
screen display characteristics. For Web page appearances, the World Wide Web Consortium (W3C) developed
a complementary markup system called Cascading Style Sheets (CSS) to make it easier to define a page's
appearance without affecting its HTML structure. HTML can be frustrating when trying to control the appearance
of a Web page and its contents. Style sheets work like templates: you define the style for a particular HTML
element once, and then use it over and over on any number of Web pages. To change how an element looks,
you just change the style; the element automatically changes wherever it appears. (Before CSS, you had to
change the element individually, each time it appeared.) Style sheets let Web designers more quickly create
consistent pages and more consistent web sites.
Browsers began supporting the first CSS Specification, Cascading Style Sheets, Level 1 (CSS1), in versions 3.0
of Opera and Microsoft Internet Explorer and in version 4.0 of Netscape Navigator. The 4.0 and later versions of
all three browsers also support properties from the newer Cascading Style Sheets, Level 2 (CSS2) specification,
which let you specify elements' visibilities, their precise positions on the page, and how they overlap each other.
Certificate – A cryptographically signed object that contains an identity and a public key associated with the
identity. Public key certificates are digital stamps of approval for electronic security. The three main
characteristics of certificates are 1) provide identification of the web site and the owner, 2) contain the public
key to be used to encrypt and decrypt messages between parties, and 3) provide a digital signature from the
trusted organization that issued the certificate, as well as when the certificate expires.
Certificate Authority – The issuer of a certificate is the Certificate Authority (CA). The CA is the party that
digitally signs a certificate and ensures its validity. There are two types of CAs, private and public. Private CAs
issue certificates for use in private networks where they can validate the certificate. Public CAs issues
certificates for servers that belong to the general public. A Public CA must meet certain requirements before
they are added as a root authority to a browser. Since this is a controlled process, all public CA must be
registered to issue certificates.
Certificate Revocation List – A log of certificates that have been revoked before their expiration date.
Cipher – An encryption/decryption algorithm.
Ciphertext – Encrypted data.
Client-Server Model – A common way to describe the paradigm of many network protocols. Examples include
the name-server/name-resolver relationship in DNS and the file-server/file-client relationship in NFS.
CHAP (Challenge Handshake Authentication Protocol) – An IETF standard for authentication using PPP
which uses a "random Challenge", with a cryptographically hashed "Response" which depends on the
Challenge and a secret key.
Client – A client is a program that communicates with a server via a network, so as to use the service provided
by that server. Example: Netscape is a www cli
ent, with the help of which one can call up information from a
www server.
Client-Server Principle – Applications based on the client-server principle use a client program (client) at the
user-end that exchanges information with a server on the network. Usually the server is responsible for the data
keeping, while the client takes over the presentation of this information and the interaction with the user. For
this, the server and the client employ an exactly defined protocol. All the important applications in the Internet
(e.g. www, FTP, news) are based on the client-server principle.
CMP (Certificate Management Protocol) – A protocol defining the online interactions between the end entities
and the certification authority in PKI. It is written by PKIX working group of IETF and is specified in document
RFC 2510.
Compromise – The unintended disclosure or discovery of a cryptographic key or secret.
CRL – Certificate Revocation List.