Nokia ?110 User Manual page 38

To provide secure communication over the wireless LAN, the Nokia C110/
C111 offers the Wired Equivalent Privacy (WEP) security feature. WEP uses
the RC4 algorithm with an up to 128-bit key. The algorithm provides for
security via two methods: authentication and encryption. Authentication is
the means by which one wireless station is verified to have authorisation to
communicate with a second station in a given coverage area.
In the infrastructure mode, authentication is established between an access
point and each wireless station. If a wireless station receives a packet that has
not been scrambled with a correct key, the packet is discarded. Encrypted
messages can be opened by other wireless LAN cards only if they all use the
same encryption key. In the ad hoc mode, authentication is established
between each wireless station.
The WEP feature offers a security level comparable to that of wired
networks. The level of security is dependent on the length of the key: the
more bits there are in the key, the longer it takes to decrypt the information
sent and the higher the level of security.
WEP keys consist of a secret key and a 24-bit Initialization Vector. For
example, the 104-bit WEP key has a 104-bit secret key which the user can set,
and a 24-bit Initialization Vector that cannot be controlled by the user. Some
manufacturers refer to the 104-bit key as a 104-bit key, whereas others refer
to it as a 128-bit key (104+24). Both keys offer the same level of encryption
and are therefore interoperable.
Other manufacturer's 128-bit keys may not be compatible with the
128-bit key (128+24) used with the Nokia C110/C111. Instead, with the
Nokia C110/C111 you may need to use the 104-bit key (104+24) to
ensure compatibility with other manufacturer's 128-bit keys.
There are two types of WEP keys: shared keys and personal keys.
Shared keys
Shared WEP keys are shared by all wireless stations using the network or
subnetwork; only stations that have the correct key can receive and decrypt
data. The same key is loaded into the access point. Shared keys are usually
created by system administrators, who distribute them to users. In the ad hoc
operating mode, the person who is creating the ad hoc network decides on a
password and then distributes it to others. The system uses this password to
create a shared WEP key.
Shared keys are network-specific, and each network can have up to 4
different shared keys. The name of a shared key is the same as the name of the
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