Handle edge cases in notifications

**Feature request**
It would be great to have encryption for controllers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_encryption` with default `false`.

The issue names no files, tests, or entry points, and does not define which controllers or encryption behavior are in scope. First identify the relevant controller and configuration entry points, then clarify the encryption design and tests needed to verify that enable_encryption defaults to false and the requested production use case is covered.

Written by the indexing model from the issue text.