Applying security to existing PDF documents

Q: I'm working on a .Net C# application that creates PDF files using
Crystal Reports. Crystal Reports doesn't support encrypting PDF's. My
client doesn't want the PDF's to be editable or allow content copying.
So, I wanted a component that I could integrate into my application,
that would allow all the PDF's created in Crystal to be further
processed to add the security settings the client requires. I don't
want a command line tool, I wanted something like a .Net managed DLL I
could reference in my project that would add security settings to the
PDF's created in Crystal.

From looking at your products it seems like the PDFSecure SDK might do

the trick. Is this a valid use of the PDFSecure SDK?
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A: You can use either PDF Secure SDK (http://www.pdftron.com/
pdfsecure) or PDFNet SDK (http://www.pdftron.com/net) to apply (or
modify) security on existing PDF documents. In case you are interested
in PDFNet SDK a good starting point for your project would be EncTest
sample project (http://www.pdftron.com/net/samplecode.html#EncTest).

For example (in C#):

PDFDoc doc = new PDFDoc("in.pdf");
StdSecurityHandler new_handler = new StdSecurityHandler();
new_handler.ChangeUserPassword("test");

// Set Permissions
new_handler.SetPermission(SecurityHandler.Permission.e_print, true);
new_handler.SetPermission(SecurityHandler.Permission.e_extract_content,
false); doc.SetSecurityHandler(new_handler);

doc.Save("secured.pdf", 0);
doc.Close();