I'm looking for a program that allows me to export a document to PDF safely, so that other users can open it but can not copy or print its contents.
While I used Windows I used PDF printers such as PDF24 and BullZip, which allowed me to create documents with these characteristics. But when I opened these documents from my Ubuntu with Okular or Document Viewer, all safety features disappeared. So, I could copy and print documents protected by Windows on Ubuntu.
My question then is: how I can protect PDFs on all platforms? I'm looking for something easy to use because it will be used by people who have NO extensive knowledge in computers.
Thanks a lot.