Watchguard Firebox X1000 Reference Manual page 120

CHAPTER 9: Glossary
108
Address Resolution Protocol (ARP)
A TCP/IP protocol used to convert an IP address into a physical
address such as an Ethernet address.
address space probe
An intrusion measure in which a hacker sequentially attacks IP
addresses. These probes are usually attempts to map IP address
space to look for security holes that a sender might exploit to
compromise system security.
agent
A computer program that reports information to another
computer or allows another computer access to the local system.
Agents can be used for good or malice. Many security programs
have agent components that report security information back to a
central reporting platform. However, agents can also be remotely
controlled programs hackers use to access machines.
AH (authentication header)
A protocol used in IPSec available for use with IPSec Branch
Office VPN. AH provides authentication for as much of the IP
header as possible (except for mutable fields that are
nondeterministic, such as TTL fields) and all upper protocols and
payload. It offers the functionality of ESP except for
confidentiality, which ESP's encryption provides.
algorithm (encryption)
A set of mathematical rules (logic) used in the processes of
encryption and decryption.
algorithm (hash)
A set of mathematical rules (logic) used in the processes of
message digest creation and key/signature generation.
alias
A shortcut that enables a user to identify a group of hosts,
networks, or users with one identifying name. Aliases are used to
speed user authentication and service configuration.
Application Program Interface (API)
Software that allows dissimilar software products to interact upon
one another.
WatchGuard Firebox System