How to set security options to create PDF using pdflatex

Question

My questions is very simple. How can I set security setting for a PDF file created with PDFLatex?

I should set some password or print permissions, etc.

Answer 1

This answer, taken partially verbatim from Digital signature on TeX.SX:

Using the PDF Toolkit you can specify a separate owner and user password. Owner passwords are required when changing document properties, while user passwords may be required for performing certain actions, like printing. However, only specifying an owner password and allowing printing by default, would allow users of the document to view/read/print without authentication. You would need the following command line execution:

pdftk input.pdf output output.pdf owner_pw foo allow printing

The above commands takes as input input.pdf, sets the owner password to foo and would allow printing by any user. Modification of document settings require the owner password. See the documentation/man page and examples for more information.