MENU
What does WPA3-Personal use as the source to generate a different Pairwise Master Key (PMK) each time a station connects to the wireless network?
The source that WPA3-Personal uses to generate a different Pairwise Master Key (PMK) each time a station connects to the wireless network is session-specific information (MACs and nonces). WPA3-Personal uses Simultaneous Authentication of Equals (SAE) to replace PSK authentication in WPA2-Personal. SAE is a secure key establishment protocol that uses a Diffie-Hellman key exchange to derive a shared secret between two parties without revealing it to an eavesdropper. SAE involves the following steps:
The station and the access point exchange Commit messages that contain their MAC addresses and random numbers called nonces.
The station and the access point use their own passwords and the received MAC addresses and nonces to calculate a shared secret called SAE Password Element (PE).
The station and the access point use their own PE and the received MAC addresses and nonces to calculate a shared secret called SAE Key Seed (KS).
The station and the access point use their own KS and the received MAC addresses and nonces to calculate a shared secret called SAE Key Confirmation Key (KCK).
The station and the access point use their own KCK and the received MAC addresses and nonces to calculate a confirmation value called SAE Confirm.
The station and the access point exchange Confirm messages that contain their SAE Confirm values.
The station and the access point verify that the received SAE Confirm values match their own calculated values. If they match, the authentication is successful and the station and the access point have established a shared secret called SAE PMK.
The SAE PMK is different for each session because it depends on the MAC addresses and nonces that are exchanged in each authentication process. The SAE PMK is used as an input for the 4-way handshake that generates the Pairwise Temporal Key (PTK) for encrypting data frames.
The other options are not sources that WPA3-Personal uses to generate a different PMK each time a station connects to the wireless network because:
Opportunistic Wireless Encryption (OWE): OWE is a feature that provides encryption for open networks without requiring authentication or passwords. OWE uses a similar key establishment protocol as SAE, but it does not generate a PMK. Instead, it generates a Pairwise Secret (PS) that is used as an input for the 4-way handshake that generates the PTK.
Simultaneous Authentication of Equals (SAE): SAE is not a source, but a protocol that uses session-specific information as a source to generate a different PMK each time a station connects to the wireless network.
Key Encryption Key (KEK): KEK is not a source, but an output of the 4-way handshake that generates the PTK. KEK is used to encrypt group keys that are distributed by the access point.