Error (0x08) - Error code for key handshake failures
GTK (0x01) - Group Temporal Key for multicast/broadcast traffic
IGTK (0x09) - Integrity Group Temporal Key for protected management frames (802.11w)
Key ID (0x0a) - Key identifier for various key types
Lifetime (0x07) - Key lifetime in seconds
MAC Address (0x03) - Used in TDLS and peer-to-peer communications
Multiband GTK (0x0b) - Group key for multi-band operation
Multiband Key ID (0x0c) - Key identifier for multi-band GTK
Nonce (0x06) - Additional nonce for key derivation
PMKID (0x04) - Pairwise Master Key Identifier for fast roaming
SMK (0x05) - Station-to-Station Master Key for TDLS
KDE (Key Data Encapsulation) Data Type - identifies vendor-specific key data elements in EAPOL Key frames (uses OUI 00:0F:AC)