User's Manual

Chapter 3 — Configuring the Computer
48 741 and 751 Mobile Computers (Windows Mobile 5.0) User’s Manual
There are many schemes available to implement these features. Use the
following tables to understand the common terminology for wireless
network security.
Encryption Terminology
Acronym Description
AES
(Advanced Encryption
Standard)
A block cipher, a type of symmetric key cipher that uses groups of
bits of a fixed length - called blocks. A symmetric key cipher is a
cipher using the same key for both encryption and decryption.
As implemented for wireless, this is also known as CCMP, which
implements AES as TKIP and WEP are implementations of
RC4.
CKIP (Cisco Key
Integrity Protocol)
This is Cisco’s version of the TKIP protocol, compatible with
Cisco Aironet products.
TKIP (Temporal Key
Integrity Protocol)
This protocol is part of the IEEE 802.11i encryption standard for
wireless LANs, which provides per-packet key mixing, a message
integrity check and a re-keying mechanism, thus overcoming
most of the weak points of WEP. This encryption is more
difficult to crack than the standard WEP. Weak points of WEP
include: No Initiation Vector (IV) reuse protection, weak keys,
no protection against message replay, no detection of message
tampering, and no key updates.
WEP (Wired
Equivalent Privacy)
encryption
With preconfigured WEP, both the client 751 and access point
are assigned the same key, which can encrypt all data between the
two devices. WEP keys also authenticate the 751 to the access
point - unless the 751 can prove it knows the WEP key, it is not
allowed onto the network. WEP keys are only needed if they are
expected by your clients. There are two types available: 64-bit (5-
character strings, 12345) (default) and 128-bit (13-character
strings, 1234567890123).
Key Management Protocols Terminology
Acronym Description
WPA (Wi-Fi
Protected Access)
This is an enhanced version of WEP that does not rely on a static,
shared key. It encompasses a number of security enhancements over
WEP, including improved data encryption via TKIP and 802.11b/g
authentication with EAP. WiFi Alliance security standard is designed
to work with existing 802.11 products and to offer forward
compatibility with 802.11i.
WPA2 (Wi-Fi
Protected Access)
Second generation of WPA security. Like WPA, WPA2 provides
enterprise and home Wi-Fi users with a high level of assurance that
their data remains protected and that only authorized users can access
their wireless networks. WPA2 is based on the final IEEE 802.11i
amendment to the 802.11 standard ratified in June 2004. WPA2 uses
the Advanced Encryption Standard (AES) for data encryption and is
eligible for FIPS (Federal Information Processing Standards) 140-2
compliance.