3Com WXR100 3CRWXR10095A, WX4400 3CRWX440095A, WX1200 3CRWX120695A Configuring User Encryption

284CHAPTER 13: CONFIGURING USER ENCRYPTION

Configuring WPA Wi-Fi Protected Access (WPA) is a security enhancement to the IEEE

802.11wireless standard. WPA provides enhanced encryption with new cipher suites and provides per-packet message integrity checks. WPA is based on the 802.11i standard. You can use WPA with 802.1X authentication. If the client does not support 802.1X, you can use a preshared key on the MAP and the client for authentication.

WPA Cipher Suites WPA supports the following cipher suites for packet encryption, listed from most secure to least secure:

„Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) — CCMP provides Advanced Encryption Standard (AES) data encryption. To provide message integrity, CCMP uses the Cipher Block Chaining Message Authentication Code (CBC-MAC).

„Temporal Key Integrity Protocol (TKIP) — TKIP uses the RC4 encryption algorithm, a 128-bit encryption key, a 48-bit initialization vector (IV), and a message integrity code (MIC) called Michael.

„Wired Equivalent Privacy (WEP) with 104-bit keys — 104-bit WEP uses the RC4 encryption algorithm with a 104-bit key.

„WEP with 40-bit keys — 40-bit WEP uses the RC4 encryption algorithm with a 40-bit key.

You can configure MAPs to support one or more of these cipher suites. For all of these cipher suites, MSS dynamically generates unique session keys for each session. MSS periodically changes the keys to reduce the likelihood that a network intruder can intercept enough frames to decode a key.