In ________, users authenticate themselves to the access point via the use of a single, shared initial key.

• A. WEP
• B. 802.11i pre-shared key mode
• C. WPA pre-shared key mode
• D. All of the above

Answer: (D)

This question hinges on how authentication works when a single shared secret is used across the network. In a pre-shared key setup, the access point and every client use the same secret to prove they should be allowed onto the network. That’s exactly how WEP can operate when using shared-key authentication, and it’s also how WPA and 802.11i (WPA2) function when configured in PSK mode. In all these cases, there isn’t a unique credential for each user; access is granted to anyone who knows the shared initial key, established through the pairwise handshake processes that derive session keys from that secret. So the description applies to all three scenarios. Remember, while PSK setups are easy to deploy, they sacrifice per-user authentication and can be risky if the shared key is weak or exposed.