A low cost acceleration method for hardware trojan detection based on fan-out cone analysis

Fabless semiconductor industry and government agencies have raised serious concerns about tampering with inserting hardware Trojans in an integrated circuit supply chain in recent years. In this paper, a low hardware overhead acceleration method of the detection of HTs based on the insertion of 2-to-1 MUXs as test points is proposed. In the proposed method, the fact that one logical gate has a significant impact on the transition probability of the logical gates in its logical fan-out cone is utilized to optimize the number of the insertion MUXs. The nets which have smaller transition probability than the threshold value set by the user and minimal logical depth from the primary inputs are selected as the candidate nets. As for each candidate net, only its input net with smallest signal probability is required to be inserted the MUXs based test points until the minimal transition probability of the entire circuit is no smaller than the threshold value. Experiment results on ISCAS´89 benchmark circuits show that our proposed method can achieve remarkable improvement of transition probability with small overhead penalty.