ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / PDFFormat Class / MasterPassword Property

MasterPassword Property
Gets or sets the master password to protect the file. The password will need to be entered for editing and printing file.
Syntax
public string MasterPassword {get; set;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.5 or higher.
See Also