Cisco Wireless LAN Security

Shared-Key Authentication

In the realm of WLANs, the shared key is one of the more secure methods of authentication; it is based on a challenge-response protocol. The shared-key authentication requires WEP mechanisms and thus depends on a WEP infrastructure.

Note

Shared-key authentication is not a true authentication mechanism per se. Looking at the messages, it is a protocol that merely establishes proof that both parties share the same secret, but it does not prove or authenticate each party’s identity.

Protocol Choreography

Shared-key authentication requires a six-step process with four messages, as detailed in Figure 5-3.

Figure 5-3. Shared-Key Authentication

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Step 1 is the authentication request to an AP, followed ...