In order to effectively detect whether the chip is inserted into the hardware Trojan circuit during the design and manufacturing process

a method is proposed to increase the transition probability of the circuit nodes by inserting 2-to-1 MUXs in the chip design stage. The main input of the candidate node whose transition probability is lower than the transition probability threshold is inserted into the MUX to improve the transition probability of the relevant nodes

so as to realize acceleration of hardware Trojan detection in the circuit. The optimization of the insertion algorithm is realized by analyzing the fan-out cone and logic topology

and the node with the greatest influence on the transition probability of the whole circuit is selected as the candidate node

thus the number of MUXs insertion is reduced. Meanwhile

the critical path delay limit is increased to avoid the critical path delay of the circuit exceeding the preset threshold. The input terminals of the pre-designed hardware Trojan circuit are inserted into the nodes with small transition probability in the circuit

and the excitation signal is inputted to the input terminals of the circuit to analyze the change of the circuit's transition probability and the activation probability of the hardware Trojan circuit before and after the MUX insertion. The experimental results of the ISCAS'89 reference circuit show that the number of nodes whose transition probability is less than the transition probability threshold in the circuit is significantly lower; the probability of the inserted hardware Trojan being activated is significantly improved; the increased percentage of circuit critical path delay is controlled within a preset scale factor.