We are looking for a way to modify/encrypt documents, so that they are only usable to a specified date. Also copies the staff might create have to inherit this property. OS will be Windows Vista, documents are .pdf or .doc.
Do you know one?
I am aware that this is absolutely no protection against text extraction/printing/photos/screenshots, yes.
You wrote "This will let you do a lot of what you were requesting" - obviously, I request two features: "day-x-selfdestruct" and inheritance when copied. What of these 2 don't you see as fulfilled?