Perhaps I am missing something in the documentation, which shows how to encrypt existing documents together with setting what Adobe Reader shows in the Document Properties / Security tab.

However, I do not want to encrypt the document, what I want to accomplish is that my document will show:

--- Document Restrictions Summary -----

     Signing: Allowed

Documents I create with iText say, by default:

     Signing: Not Allowed

Of course, I would like to play with other “restrictions”, for example say Content Copying: Not Allowed _without_ having to encrypt, but that is secondary. I do not think it is required to have document encrypted in order to allow (counter) signing it.