Key Derivation from Preshared Key and EAP

D.

The key derived from a preshared key and Extensible Authentication Protocol (EAP) is the Pairwise Master Key (PMK), so the correct answer is D.

When a wireless client device wants to connect to a Wi-Fi network, it first authenticates itself to the network through the use of an EAP method. EAP is an authentication framework that supports a variety of authentication methods, such as username/password, digital certificates, and tokens.

Once the client device has been authenticated, it derives a Pairwise Master Key (PMK) from the preshared key and the EAP authentication exchange. The PMK is used to generate a Pairwise Transient Key (PTK), which is unique to the client device and the Wi-Fi access point.

The PTK is used to encrypt data sent between the client device and the access point using the Temporal Key Integrity Protocol (TKIP) or the Advanced Encryption Standard (AES). The PTK is also used to generate a Group Temporal Key (GTK), which is used to encrypt data sent between the access point and multiple client devices.

In summary, the PMK is derived from a preshared key and EAP, and is used to generate the PTK and GTK for securing wireless communications between client devices and Wi-Fi access points.