To protect the PDF with a password, you can take the help of a reliable utility like PDFCHAMP Secure PDF Tool. This application helps to protect PDFs with a password, and using it does not require any other installation. This application helps you to set restrictions on PDF files for printing, copying, and editing. Also, this software application does not require any technical skill to utilize the program. This advanced application locks your PDF without losing structure and data, whether the PDF is lightweight or heavy. This application smoothly works on all Windows versions without limitations.