How do I make it so the chat message are encrypted so that even someone with admin database access cannot read them?

Not sure where else to post this question… but how do I make it so that everything is secure for my users? As it is now, it appears that an admin could go in and read messages between people. Even though I’m the only person with admin access to the database, I’d prefer that even I were unable to read messages between users. How do I configure this?