The below example shows how an 802.11 authentication occurs via the Pre-Shared Key Authentication Mechanism. For an understanding of the Pre-Shared key Mechanism refer here <802.11 Pre-Shared Key Mechanism>. The below example shows a WPA-PSK example.
- AP sends a beacon packet with the WPA Information element with the Authentication Key Management as PSK and in this particular example TKIP as the Multicast and unicast cipher suite supported
- The WLAN station intending to connect to the Access Point sends a probe request. The probe request frame has no information elements for WPA
- The Access Point responds with a Probe Response with the WPA Information element incorporated in the Probe Response
- The 802.11 Authentication frames are exchanged with authentication set as open system authentication. This is because the upper layer authentication is indicated by the WPA information element
- The Association Request and the Association Response frames are exchanged. At the end of the association handshake. The WLAN Station is connected to the Access Point but the data port is still blocked.
- The below figure indicates the steps till association
