Adam
works as a Network Administrator. He discovers that the wireless AP transmits 128 bytes of
plaintext, and the station responds by encrypting the plaintext. It then transmits the resulting
ciphertext using the same key and cipher that are used by WEP to encrypt subsequent network
traffic. Which of the following types of authentication mechanism is used here?

A.
Pre-shared key authentication

B.
Open system authentication

C.
Shared key authentication

D.
Single key authentication

Explanation:
Shared key authentication is an authentication method specified in the 802.11
standard. In this authentication, a static WEP key should be
configured on the client. The shared key authentication has the following processes:
1.The client makes a request to the access point for shared key authentication by sending an
authentication request.
2.The access point sends authentication response to the client. Authentication response contains
challenge text in a clear text format.
3.The client uses its locally configured WEP key to encrypt the challenge text and replies with a
subsequent authentication request.
4.If the access point can decrypt the authentication request and retrieve the original challenge text,
then it responds with an
authentication response that allows the client to access the network.