dentifies the broadcasting device's RSN capabilities in beacon, probe, association and reassociation frames. The IE identifies specific RSN capabilities; supported authentication and key management mechanisms, and ciphers for unicast or multicast messages, as described in Table 8-4. The selection of security parameters occurs through the following exchange; Step (1) The client station broadcasts a Probe Request. Step (2) The access point broadcasts a Probe Response including an RSN IE. Step (3) The client station sends an Open System Authentication request to the access point. Step (4) The access point provides an Open System Authentication response to the client. Step (5) The client station sends an Association Request with an RSN IE indicating its choice of RSN capabilities. Step (6) The access point send an Association Response indicating success if the client station's selected security parameters are supported by the access point. Notice that this exchange is unprotected and, since Open System Authentication is used (see the Section "Station Services, p. 147"), there is effectively no authentication between the client station and the access Table 8-4: RSN Information Element content RSN capability Description Supported authentication and RSN devices can either support 802.1x key management authentication and key management or mechanisms 802. 1x key management with no authentication Supported ciphers RSN devices may support any of the following ciphers for either unicast or multicast message encryption (WEP, TKIP, WRAP and AES- CCMP) Chapter Eight point. This does not introduce a security threat since the exchange simply serves to establish the protocol and cipher that will then be used to ensure mutual authentication and subsequent data privacy. To provide a degree of backward compatibility with legacy equipment, networks that use RSN but do not have the required hardware to support AES will allow the use of TKIP/RC4 for encryption. This interim step towards full RSN is referred to by the term transition sec