| Type | Type Value | Description | Contents |
| KEY_REQUEST | 0x06 | Sent by nodes to the PKG | Enc(timestamp), , |
| KEY_REPLY | 0x07 | Sent by PKG to nodes as a reply to KEY_REQUEST message | Enc(System Parameters, node , private key), , |
| JOIN | 0x01 | Broadcasted by nodes who wants to join a group | node , timestamp, JOIN token |
| INVITE | 0x02 | Broadcasted by controller for inviting nodes to form a group | (participant , node , participant , ) |
| READY | 0x03 | Broadcasted by nodes as a reply to INVITE message | participant , timestamp, READY token |
| ROUND_1 | 0x04 | Contains cryptographic material for the first round of the GKA | sender , Crypto R1 |
| ROUND_2 | 0x05 | Contains cryptographic material for the second round of the GKA | sender , receiver , Crypto R2 |
| DATA | 0x08 | Contains encrypted data with the group key | sender , receiver , Enc(data), , |
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