Security Solutions

A-22
Appendix A: Glossary
TLS Transport Layer Security. The successor to SSL. It prevents eavesdropping
on communications between Internet client and server. For more information,
see RFC 2240 at http://www.ietf.org/rfc/rfc2246.txt.
transient agent An agent that is installed on the endpoint for a short time only at the beginning
of each test. The ActiveX test method uses a transient agent.
Troja n A malicious program disguised as or embedded within legitimate software.
The term comes from the classical myth of the Trojan horse—something that
looks useful, interesting, or harmless, but is actually harmful when executed.
Trojans cannot operate autonomously, in contrast to some other types of
malware such as viruses or worms. Trojans “hitch a ride” on an executable
program that the intended victim must deliberately launch.
There are two common types of Trojan. One is found in otherwise useful
software that has been corrupted by the insertion of the Trojan, which
executes while the program is used, for example, in weather-alerting pro-
grams, computer clock-setting software, and peer-to-peer file-sharing utilities.
The other type of Trojan is a standalone program that masquerades as some-
thing else, such as program that claims to rid your hard drive of viruses but in
fact inserts them.
TTLS Tunneled TLS. An extension to TLS that does not require the client to be
authenticated by a CA-signed PKI certificate. For more information, see the
Internet Draft at http://tools.ietf.org/wg/eap/draft-funk-eap-ttls-v0-01.txt.
U
UDP User Datagram Protocol. A stateless protocol that is part of the IP protocol
suite. Using UDP, programs on network computers can send datagrams to one
another. UDP does not provide the reliability and ordering guarantees that
TCP does; datagrams may arrive out of order or go missing without notice.
However, UDP is faster and more efficient for many lightweight or time-
sensitive programs. For more information, see RFC 768 at http://www.ietf.org/
rfc/rfc0768.txt.
UMTS Universal Mobile Telecommunications System. A third-generation cellular
technology successor to GSM. Also called 3GSM. For more information, see
the specification at http://www.3gpp.org/ftp/Specs/html-info/21101.htm.
unmanaged
endpoint
A device that is not under the company’s administrative control. Examples
include a guest’s computer or a contractor’s computer. Such a device is still
subject to the company’s network security policies.