A locking system for an integrated circuit (IC) chip can include an arrangement of one or more antifuse devices in a signal path of the IC chip. The antifuse devices can be configured to operate in a first state, corresponding to a normally open switch, to inhibit normal operation of the IC chip, and to transition from the first state to a permanent second state, corresponding to a closed switch, in response to a program signal applied to at least one terminal of the IC chip to enable the normal operation of the IC chip.