A method for preventing illicit copying of an application specific integrated circuit (ASIC). The ASIC is defined by a net list which includes a timer circuit for disabling the ASIC. The timer circuit includes a plurality of stages which are distributed in different cores of the ASIC to inhibit detection and removal of the circuit. The timer times out after a period which is set to permit evaluation of the ASIC design. Following the time out period, further use of the ASIC design is inhibited.