Support notifications configuration

**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`.

Start by locating the controller configuration entry point and existing configuration tests; the issue does not name files or test cases. Clarify what “encryption for controllers” protects, how enable_encryption should affect production deployments, and which encrypted data or behavior defines done before implementation.

Written by the indexing model from the issue text.