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ZyXEL – SBG Support Notes
Wired Equivalent Privacy (WEP) is a security mechanism defined within the
802.11 standard and designed to make the security of the wireless
medium equal to that of a cable (wire). WEP data encryption was designed
to prevent access to the network by "intruders" and to prevent the capture
of wireless LAN traffic through eavesdropping. WEP allows the
administrator to define a set of respective "Keys" for each wireless network
user based on a "Key String" passed through the WEP encryption algorithm.
Access is denied by anyone who does not have an assigned key. WEP
comes in 40/64-bit and 128-bit encryption key lengths.
Note that WEP was shown to have fundamental flaws in its key generation
processing.
What is the difference between 40-bit and 64-bit WEP?
40-bit WEP & 64-bit WEP are the same encryption level and can
interoperate. The lower level of WEP encryption uses a 40-bit (10 Hex
character) as "secret key" (set by user), and a 24-bit "Initialization Vector"
(not under user control) (40+24=64). Some vendors refer to this level of
WEP as 40-bit, others as 64-bit.
What is a WEP key?
A WEP key is a user defined string of characters used to encrypt and
decrypt data.
Can the SSID be encrypted?
WEP, the encryption standard for 802.11, only encrypts the data packets,
not the 802.11 management packets; however, the SSID is in the beacon
and probe management messages. The SSID is not encrypted if WEP is
turned on. The SSID is transmitted over the air in clear text. This makes
obtaining the SSID easy by sniffing 802.11 wireless traffic.
By turning off the broadcast of SSID, can someone still sniff the
SSID?
Many APs by default have broadcasting the SSID turned on. Sniffers
typically will find the SSID in the broadcast beacon packets. Turning off the
broadcast of SSID in the beacon message (a common practice) does not
prevent getting the SSID, since the SSID is sent in the clear in the probe
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