Protected electronic designs permit appropriate simulation and testing of the electronic design in a simulation environment, while preventing a correctly operating unauthorized implementation of the electronic design in a hardware environment such as a programmable device. An unprotected version of the simulation version of an electronic design is augmented by adding protection circuitry to the unprotected version to create a protected version of the electronic design, which operates correctly in a simulation environment but which fails to operate correctly in a hardware environment. In some embodiments of the present invention, a separate programming version which does not incorporate the protection circuitry of the simulation version may also be provided for licensed/authorized users of the electronic design, which may be an IP core or other design.