wifi - 802.11i

https://en.wikipedia.org/wiki/IEEE_802.11i-2004

Pairwise Transient Key (64 bytes) is divided into five separate keys:

1.   16 bytes of EAPOL-Key Confirmation Key (KCK)– Used to compute MIC on WPA EAPOL Key message

2.   16 bytes of EAPOL-Key Encryption Key (KEK) - AP uses this key to encrypt additional data sent (in the 'Key Data' field) to the client (for example, the RSN IE or the GTK)

3.   16 bytes of Temporal Key (TK) – Used to encrypt/decrypt Unicast data packets

4.   8 bytes of Michael MIC Authenticator Tx Key – Used to compute MIC on unicast data packets transmitted by the AP

5.   8 bytes of Michael MIC Authenticator Rx Key – Used to compute MIC on unicast data packets transmitted by the station

The Group Temporal Key (32 bytes) is divided into three separate keys:

1.   16 bytes of Group Temporal Encryption Key – used to encrypt/decrypt Multicast and Broadcast data packets

2.   8 bytes of Michael MIC Authenticator Tx Key – used to compute MIC on Multicast and Broadcast packets transmitted by AP

3.   8 bytes of Michael MIC Authenticator Rx Key – currently unused as stations do not send multicast traffic