A circuit protection method based on replacing minterms with combinatorial circuits

This paper introduces an integrated circuit camouflage strategy based on the minterms. The modified circuit can be well protected against SAT attacks. The method consists of two main steps: finding minterms and perturbing the circuit. This approach applies to multi-output circuits. This method allows for quick and accurate identification of minterms and the generation of circuits with significantly enhanced output disturbances. Experiments conducted on the OpenSPARC microprocessor using the ISCAS'85 and ISCAS'89 benchmark circuits demonstrate the effectiveness of our method. The time to find a minterm is only about 0.03s. The average correctness of the search is more than 90 %. The combinatorial circuit is resistant to SAT attack after replacement of the minterm. Moreover, the perturbation of circuit outputs significantly surpasses that of the original CamoPerturb structure, with one of the most notable improvements being an enhancement of approximately 330 times.