Extreme Networks Altitude 4700 Series Product Reference Manual page 29

interpret the encrypted data without the appropriate key. Only the sender and receiver of the
transmitted data know the key.
Wired Equivalent Privacy (WEP) is an encryption security protocol specified in the IEEE Wireless Fidelity
(Wi-Fi) standard, 802.11b and supported by the AP. WEP encryption is designed to provide a WLAN
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 Access Point. An Access Point and its associated wireless clients
must use the same encryption key (typically 1 through 4) to interoperate.
For detailed information on WEP, see
KeyGuard Encryption
Use KeyGuard to shield the master encryption keys from being discovered through hacking. KeyGuard
negotiation takes place between the Access Point and MU upon association. The Access Point can use
KeyGuard with certain Motorola MUs. KeyGuard is only supported on certain Motorola MUs.
For detailed information on KeyGuard configurations, see
page 209.
Wi-Fi Protected Access (WPA) Using TKIP Encryption
Wi-Fi Protected Access (WPA) is a security standard for systems operating with a Wi-Fi wireless
connection. WEP's lack of user authentication mechanisms is addressed by WPA. Compared to WEP,
WPA provides superior data encryption and user authentication.
WPA addresses the weaknesses of WEP by including:
a per-packet key mixing function
●
a message integrity check
●
an extended initialization vector with sequencing rules
●
a re-keying mechanism
●
WPA uses an encryption method called Temporal Key Integrity Protocol (TKIP). WPA employs 802.1X and
Extensible Authentication Protocol (EAP).
For detailed information on WPA using TKIP configurations, see
TKIP" on page 211.
WPA2-CCMP (802.11i) Encryption
WPA2 is a newer 802.11i standard that provides even stronger wireless security than Wi-Fi Protected
Access (WPA) and WEP. Counter-mode/CBC-MAC Protocol (CCMP) is the security standard used by the
Advanced Encryption Standard (AES). AES serves the same function TKIP does for WPA-TKIP. CCMP
computes a Message Integrity Check (MIC) using the proven Cipher Block Message Authentication Code
(CBC-MAC) technique. Changing just one bit in a message produces a totally different result.
WPA2-CCMP is based on the concept of a Robust Security Network (RSN), which defines a hierarchy of
keys with a limited lifetime (similar to TKIP). Like TKIP, the keys the administrator provides are used to
derive other keys. Messages are encrypted using a 128-bit secret key and a 128-bit block of data. The
end result is an encryption scheme as secure as any the Access Point provides.
Altitude 4700 Series Access Point Product Reference Guide
"Configuring WEP Encryption" on page
"Configuring KeyGuard Encryption" on
208.
"Configuring WPA/WPA2 Using
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