Add unit tests for types

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

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

**Priority**: Low/Medium

Start by inspecting the lib directory and locating the type definitions and existing unit-test layout. Clarify how the proposed configurable encryption relates to the “types” in the title, then identify the expected defaults and test cases. Done means the encryption behavior and its defaults are covered by unit tests.

Written by the indexing model from the issue text.