PDF Password - PDF specification allows owners to specify up to two passwords for a document to protect and encrypt it: an owner password and a user password. Doxillion Document Converter needs access permission for copy or extract page contents from the document according to PDF specification. Therefore, Doxillion requires to enter an owner password if the PDF document does not have "copy" permission, although PDF readers can open it. Doxillion does not pop up this dialog if the PDF is not encrypted or disabled "copy" permission.