Add rate limiting for serialization

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

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

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

The title asks for rate limiting during serialization, while the body asks for encryption and an `enable_encryption` configuration option. Start by locating the serialization and configuration handling in the repository, then clarify which behavior is intended before defining completion criteria.

Written by the indexing model from the issue text.