Motorola CB3000 - Client Bridge - Wireless Access Point, Руководство пользователя

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D-2 CB3000 Client Bridge User’s Guide
D.1 WEP Security
All WLAN devices face possible information theft. Theft occurs when an unauthorized user eavesdrops to
obtain information illegally. The absence of a physical connection makes wireless links particularly
vulnerable to this form of theft. Most forms of security rely on encryption to various extents.
Encryption entails scrambling and coding information, typically with mathematical formulas called
algorithms, before the information is transmitted. An algorithm is a set of instructions or formula for
scrambling the data. A key is the specific code used by the algorithm to encrypt or decrypt the data.
Decryption is the decoding and unscrambling of received data. WEP may be all that a retail business needs
for the simple encryption of wireless data. However, networks that require more security are at risk from a
WEP flaw and should use a more sophisticated method for securing their CB3000 Client Bridge managed
network.
The same device, host computer or front-end processor, usually performs both encryption and decryption. The
data transmit or receive direction determines whether the encryption or decryption function is performed.
The device takes plain text, encrypts or scrambles the text typically by mathematically combining the key
with the plain text as instructed by the algorithm, then transmits the data over the network. At the receiving
end another device takes the encrypted text and decrypts, or unscrambles, the text revealing the original
message. An unauthorized user can know the algorithm, but cannot interpret the encrypted data without the
appropriate key. Only the sender and receiver of the transmitted data know the key.
WEP is an encryption security protocol specified in the IEEE Wireless Fidelity (Wi-Fi) standard, 802.11b and
supported by the CB3000 Client Bridge. WEP encryption is designed to provide a wireless device with a level
of security and privacy comparable to that of a wired LAN.
The level of protection provided by WEP encryption is determined by the encryption key length and algorithm.
An encryption key is a string of case sensitive characters used to encrypt and decrypt data packets
transmitted between a
mobile unit (MU) and the CB3000 Client Bridge. An CB3000 Client Bridge and
associated device must use the same encryption key (typically 1 through 4) and the same WEP algorithm to
inter-operate.
For detailed steps on configuring WEP for the CB3000 Client Bridge, see Configuring WEP Security Settings
on page 3-8 .