Hello,
Database is encrypted at rest. That protects the data to get read outside of Campaign and Database authenticated access. So we protect data from the outside to say. Now if your need is project from the inside meaning to hide a piece of data from your Campaign users while still being able to use this data it for sending message (email address or personalization data) then this capability is indeed not here so far.
Encrypting email address at delivery / tracking logs level is then not supported on Campaign. Some mechanisms like email tokenization could be a solution for example. This is not part of the roadmap so far. That we keep the door open to explore it in the future.