While exploring the Business Chat Specs and other blogs/ forums, I have come to know that the Business Chat messages are "fully encrypted". Does this mean that each message shares a private key with Apple on the Business Chat Server? When customers provide sensitive data in the form of attachments, for example, there are other security measures that I would like to add onto Business Chat messages to ensure the privacy of customers. Essentially, can an additional layer of encryption be added onto Business Chat messages by the company enrolling with Business Chat and integrating with the Business Chat Server?