802.11i uses Extensible Authentication Protocol (EAP) with strong encryption scheme and dynamically assigns every transmission its own key to heighten the protection of the data in transmit against taping or tampering. With 802.11i enabled, logging on to wireless network is more complex than with WEP.
WPA (Wi-Fi Protected Access) is a subset of 802.11i standard that is endorsed by the Wi-Fi Alliance, an international organization dedicated to ensuring the interoperability of 802.11-capable device.
In a wireless network secured with Wi-Fi Protected Access, the AP acts as proxy between a remote access server and station until the station has successfully authenticated with the remote access server. It requires mutual authentication — the station authenticates with the remote access server, and vice versa. After authentication, remote access server instructs AP to allow traffic from the client into network. Following that, the client and server agree on an encryption key for subsequent data transmission.
WPA2 is an updated version that has already gained wide support by commercial products.
Read the following material to learn more about wireless network security:
Dean (2010) 611–14.