Authentication And Wep - NETGEAR MA111 User Manual

User Manual for the NETGEAR 11 Mbps Wireless USB Adapter MA111

Authentication and WEP

The absence of a physical connection between nodes makes the wireless links vulnerable to
eavesdropping and information theft. To provide a certain level of security, the IEEE 802.11
standard has defined two types of authentication methods, Open System and Shared Key. With
Open System authentication, a wireless PC can join any network and receive any messages that are
not encrypted. With Shared Key authentication, only those PCs that possess the correct
authentication key can join the network. By default, IEEE 802.11 wireless devices operate in an
Open System network.
Wired Equivalent Privacy (WEP) data encryption is used when the wireless devices are configured
to operate in Shared Key authentication mode. There are two shared key methods implemented in
most commercially available products, 64-bit and 128-bit WEP data encryption.
802.11 Authentication
The 802.11 standard defines several services that govern how two 802.11 devices communicate.
The following events must occur before an 802.11 Station can communicate with an Ethernet
network through an access point such as the one built in to the MA111:
Turn on the wireless station.
1.
The station listens for messages from any access points that are in range.
2.
The station finds a message from an access point that has a matching SSID.
3.
The station sends an authentication request to the access point.
4.
The access point authenticates the station.
5.
The station sends an association request to the access point.
6.
The access point associates with the station.
7.
The station can now communicate with the Ethernet network through the access point.
8.
An access point must authenticate a station before the station can associate with the access point or
communicate with the network. The IEEE 802.11 standard defines two types of authentication:
Open System and Shared Key.
• Open System Authentication allows any device to join the network, assuming that the device
SSID matches the access point SSID. Alternatively, the device can use the "Any" SSID option
(case sensitive) to associate with any available Access Point within range, regardless of its
SSID.
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Wireless Networking Basics