Improve handlers performance

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

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

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

First reconcile the title's handler-performance request with the body’s encryption-for-validation request, then locate the validation handlers and configuration entry point. Clarify what data must be encrypted and how it should behave when enable_encryption is false; done requires an agreed scope, default-false configuration, and tests for the intended behavior.

Written by the indexing model from the issue text.