According to http://docs.oracle.com/javase/7/docs/technotes/guides/jweb/security/no_redeploy.html signed Java Web Start applications and JAR files for Java Applets should contain "Codebase" and "Permissions" attributes in their MANIFEST.MF file.

When using the JavaFX Packager tool and the corresponding Ant tasks to create and sign jars it's currently not possible to specfiy these properties (at least I've not found out how).

Support for these two new attributes should be added to <fx:deploy> and <fx:signjar> Ant tasks.