Disassociation

4.10.3.5 Disassociation

Disassociation initiated by either STA in an RSNA causes the deletion of the PTKSA at both ends and the
deletion of the GTKSA in a non-AP STA. The controlled and uncontrolled ports created for this association
are also deleted.
4.10.4 IBSS functional model description
4.10.4.1 General
This subclause summarizes the system setup and operation of an RSNA in an IBSS. An IBSS RSNA is
specified in 11.5.10.
4.10.4.2 Key usage
In an IBSS the individually addressed data frames between two STAs are protected with a pairwise key. The
key is part of the PTK, which is derived during a 4-Way Handshake. In an IBSS the 4-Way Handshake may
follow IEEE 802.11 authentication of one STA to another. Such authentication may be used by the peer to
cause deletion of the PTKSA and Block the Controlled Port thus resetting any previous handshake.
In an IBSS group addressed data frames are protected by a key, e.g., named B1, that is generated by the STA
transmitting the group addressed frame. To allow other STAs to decrypt group addressed frames, B1 is sent
to all the other STAs in the IBSS. B1 is sent in an EAPOL-Key frame, encrypted under the EAPOL-Key
encryption key (KEK) portion of the PTK, and protected from modification by the EAPOL-Key
confirmation key (KCK) portion of the PTK.
In an IBSS the SME responds to Deauthentication frames from a STA by deleting the PTKSA associated
with that STA.