Why are you trying to do this? It is a very unusual request. There's probably another way to solve your requirement that does not involve doing this.
For example, if you are trying to control what the user sees - to prevent them from seeing sensitive information, If you are trying to prevent user edits, I would recommend either a) using a SharePoint workflow that moves the XML from one library to another and uses content types, or b) a Web service that restricts access based on who the form is assigned to. If you are trying to prevent user access to sensitive data I recommend either a) creating separate forms for those parts of your process that have sensitive data, b) using a Web service to restrict viewing of the entire form, or c) using qRules to just encrypt the fields in your form that are sensitive.