Refactor middleware for better readability

**Description**
Currently handlers lacks proper encryption support.

**Proposed solution**
Add configurable encryption with sensible defaults.

**Priority**: Low/Medium

Start by locating the middleware and handler entry points in the repository, then read how configuration and handler behavior are currently defined. The issue does not name files, tests, an encryption method, or default values; done would require agreed requirements plus configurable encryption with documented sensible defaults.

Written by the indexing model from the issue text.