User's Manual

Reference Manual for the Model FWAG114 Cable/DSL Wireless ProSafe Firewall
Wireless Networking Basics D-5
3. The station uses its configured 64-bit or 128-bit default key to encrypt the challenge text, and
sends the encrypted text to the access point.
4. The access point decrypts the encrypted text using its configured WEP Key that corresponds
to the station’s default key. The access point compares the decrypted text with the original
challenge text. If the decrypted text matches the original challenge text, then the access point
and the station share the same WEP Key and the access point authenticates the station.
5. The station connects to the network.
If the decrypted text does not match the original challenge text (i.e., the access point and station do
not share the same WEP Key), then the access point will refuse to authenticate the station and the
station will be unable to communicate with either the 802.11 network or Ethernet network.
This process is illustrated in below.
Figure 10-2: Shared key authentication
Overview of WEP Parameters
Before enabling WEP on an 802.11 network, you must first consider what type of encryption you
require and the key size you want to use. Typically, there are three WEP Encryption options
available for 802.11 products:
1. Do Not Use WEP: The 802.11 network does not encrypt data. For authentication purposes, the
network uses Open System Authentication.
INTERNET LOCAL
ACT
12345678
LNK
LNK/ACT
100
Cable/DSL
ProSafeWirelessVPN Security Firewall
MODEL
FVM318
PWR TEST
WLAN
Enable
Access Point1) Authentication
request sent to AP
2) AP sends challenge text
3) Client encrypts
challenge text and
sends it back to AP
4) AP decrypts, and if correct,
authenticates client
5) Client connects to network
Shared Key
Authentication Steps
Cable or
DLS modem
Client
attempting
to connect