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Chapter 7: Terminology
Chapter 7
Terminology
This chapter describes terms that are commonly used in this document.
Term Description
ADSL Asymmetric Digital Subscriber Line. A
technology allowing high-speed data transfer
over existing telephone lines. ADSL supports
data rates between 128 kbps to 8 Mbps when
receiving data and between 64 kbps to 768 kbps
when sending data.
Advanced Encryption Standard
(AES) The Advanced Encryption Standard is a new
block cipher standard to replace DES,
developed by NIST, the US National Institute of
Standards and Technology. AES ciphers use a
128-bit block and 128, 192 or 256-bit keys. The
larger block size helps resist birthday attacks
while the large key size prevents brute force
attacks.
Aggressive Mode This Phase 1 keying mode automatically
exchanges encryption and authentication keys
and uses less messages in the exchange when
compared to Main mode. Aggressive mode is
must be used to allow parties that are configured
with a dynamic IP address and a preshared
secret to connect or if the Shiva VPN Gateway or
the remote party is behind a NAT device.
Authentication Authentication is the technique by which a
process verifies that its communication partner
is who it is supposed to be and not an imposter.
Authentication confirms that data is sent to the
intended recipient and assures the recipient that
the data originated from the expected sender
and has not been altered on route.
Automatic Keying, Internet Key
Exchange (IKE) This type of keying automatically exchanges
encryption and authentication keys and replaces
them periodically.