A method providing simple fine-grain hardware primitives with which software engineers can efficiently implement enforceable separation of programs into modules and constraints on control flow, thereby providing fine-grain locality of causality to the world of software. Additionally, a mechanism is provided to mark some modules, or parts thereof, as having kernel privileges and thereby allows the provision of kernel services through normal function calls, obviating the expensive prior art mechanism of system calls. Together with software changes, Object Oriented encapsulation semantics and control flow integrity in hardware are enforced.