Security
Avaya Wireles s AP-4/5/6 Us er’s Guide 4 -125
WPA is a replacement for Wired Equivalent Privacy (WEP), the
encryption technique specified by the original 802.11 standard. WEP has
several vulnerabilities that have been widely publicized. WPA addresses
these weaknesses and provides a stronger security system to protect
wireless networks.
WPA provides the following new security measures not available with
WEP:
• Improved packet encryption using the Temporal Key Integrity
Protocol (TKIP) and the Michael Message Integrity Check (MIC).
• Per-user, per-session dynamic encryption keys:
— Each client uses a different key to encrypt and decrypt unicast
packets exchanged with the AP
— A client's key is different for every session; it changes each
time the client associates with an AP
— The AP uses a single global key to encrypt broadcast packets
that are sent to all clients simultaneously
— Encryption keys change periodically based on the Re-keying
Interval parameter
— WPA uses 128-bit encryption keys
• Dynamic Key distribution
— The AP generates and maintains the keys for its clients
— The AP securely delivers the appropriate keys to its clients