Symantec 10521146 Administration Guide - Page 344

344 Glossary digital certificate A digital certificate is an electronic credit card that establishes a user's credentials when doing business or other transactions on the Web. It is issued by a Certificate Authority (CA). It contains the user's name, a serial number, expiration dates, a copy of the certificate holder's public key (used for encrypting and decrypting messages and digital signatures), and the digital signature of the certificate-issuing authority so that a recipient can verify that the certificate is real. digital signature An electronic rather than a written signature that can be used by someone to authenticate the identity of the sender of a message or of the signer of a document. It can also be used to ensure that the original content of the message or document that has been conveyed is unchanged. Additional benefits to the use of a digital signature are that it is easily transportable, cannot be easily repudiated, cannot be imitated by someone else, and can be automatically time-stamped. direct connection A form of data communication in which one computer is directly connected to another, usually via a null modem cable. disabled A status that indicates that a program, job, policy, or scan is not available. For example, if scheduled scans are disabled, a scheduled scan does not execute when the date and time specified for the scan is reached. DMZ (de-militarized zone) A network added between a protected network and an external network to provide an additional layer of security. Sometimes called a perimeter network. DNS (Domain Name System) A hierarchical system of host naming that groups TCP/IP hosts into categories. For example, in the Internet naming scheme, names with .com extensions identify hosts in commercial businesses. DNS spoofing The act of breaching the trust relationship by assuming the Domain Name System (DNS) name of another system. This is usually accomplished by either corrupting the name service cache of a victim system or by compromising a Domain Name Server for a valid domain. domain A group of computers or devices that share a common directory database and are administered as a unit. On the Internet, domains organize network addresses into hierarchical subsets. For example, the .com domain identifies host systems that are used for commercial business. download To transfer data from one computer to another, usually over a modem or network. Usually refers to the act of transferring a file from the Internet, a bulletin board system (BBS), or an online service to one's own computer. DSX (Dynamic Security Extension) A proprietary technology that is patented and works in the following way. The operating system has a system call (or vector) table that contains memory address pointers for each system call. These pointers point to a location in memory where the actual kernel code of the system calls resides. DSX stores the address pointers for the security-sensitive system calls and then redirects these pointers to the corresponding SECURED system call code, which is located elsewhere in memory.