Publish-Subscribe Key Distribution for End-to-End Encryption

The patent segments the communication system into two distinct security layers: group-level communication (handled by the message broker) and individual end-to-end communication (established directly between communication apparatuses). This segmentation allows the message broker to handle message distribution efficiently while separate point-to-point encrypted channels ensure end-to-end security between specific communication apparatuses, resolving the contradiction between ease of operation and reliability.

The patent applies local quality by differentiating security requirements for different communication scenarios within the group. While group keys provide general message protection for all members, the invention adds individualized point-to-point encrypted channels for specific communication apparatuses. This allows messages to be protected at the group level while simultaneously ensuring that only intended recipients can access specific messages, preventing unauthorized manipulation by other group members.

The patent introduces the message broker as an intermediary that manages communication coordination between apparatuses. The broker handles message routing and distribution, while point-to-point encrypted channels are established only when specifically needed for secure end-to-end communication. This intermediary approach reduces overall system complexity by centralizing communication management while maintaining security options, avoiding the need for all apparatuses to directly manage encrypted connections with every other apparatus.