# Sentinel LDK Envelope Prerequisites

NOTE The prerequisites in this section are not required when working with Envelope with the DEMOMA Batch Code.

To protect an application with Sentinel LDK Envelope, you must have the following elements available:

>Your Vendor Code file

>A Sentinel Developer key or Master key connected to the machine used to protect applications

NOTE If you require an alternative to using a Developer key or Master key, contact Technical Support.

### Related Topics

Opening an Existing Project

Working with Binaries

Protection Parameters

Protecting a Project

Saving a Project

Key Concept: Project