Add rate limiting for search

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

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

**Priority**: Low/Medium

The title requests search rate limiting, while the body describes configurable encryption in utils. Start by inspecting the utils entry point and the search implementation, then clarify which requirement is intended; done means the chosen behavior is configurable, has sensible defaults, and is covered by the relevant checks.

Written by the indexing model from the issue text.