User's Manual

ADSL Modem
Glossary of Terms 237
Glossary of Terms
A
ADSL Modem
A device connecting a computer
to the Internet via an existing
phone line. ADSL (Asymmetric
Digital Subscriber Line) modems
offer a high-speed 'always-on'
connection.
C
Cable Modem
A device connecting a computer
to the Internet via the cable
television network. Cable
modems offer a high-speed
'always-on' connection.
Certificate Authority
The Certificate Authority (CA)
issues certificates to entities such
as gateways, users, or computers.
The entity later uses the
certificate to identify itself and
provide verifiable information.
For instance, the certificate
includes the Distinguishing
Name (DN) (identifying
information) of the entity, as
well as the public key
(information about itself), and
possibly the IP address.
After two entities exchange and
validate each other's certifcates,
they can begin encrypting
information between themselves
using the public keys in the
certificates.
Cracking
An activity in which someone
breaks into someone else's
computer system, bypasses
passwords or licenses in
computer programs; or in other
ways intentionally breaches
computer security. The end
result is that whatever resides on
the computer can be viewed and
sensitive data can be stolen
without anyone knowing about
it. Sometimes, tiny programs are
'planted' on the computer that are
designed to watch out for, seize
and then transmit to another
computer, specific types of data.
D
DHCP
Any machine requires a unique
IP address to connect to the
Internet using Internet Protocol.
Dynamic Host Configuration
Protocol (DHCP) is a
communications protocol that
assigns Internet Protocol (IP)
addresses to computers on the
network.