We are currently having an issue where we are creating a secured PDF and users on a Mac claim they can open the PDF but cannot print. We have confirmed some of them use the Mac Preview, and some are using NitroPdf.
Thanks for your patience and sorry for the delayed response.
I have tested the scenario over MAC OS X Yosemite where I have tried viewing the PDF file in Default Viewer App and when trying to print the document to PdfWriter soft printer, I am unable to notice any issue. I have observed that when trying to print the document, a prompt to enter password is displayed and unless the password is provided, one cannot print the file.
For testing purposes, I have printed the file to PDF format and PostScript format and they are properly being generated. I have also tried directly adding the print to iBooks and I can see the output in iBooks store. For your reference, I have attached the images showing my observations.
PS, I have also attached the resultant PDF (printed with PdfWriter) and PostScript file generated over my end and when viewing the PDF file, you will not observe any security restrictions.