Hardware Trojan Prevention Through Limiting Access to the Active Region

Hardware Trojan (HT) has become a serious threat to the semiconductor industry. Many solutions have been developed to detect Trojans and address hardware security concerns. However, due to the wide range of possible Trojans, specific solutions for certain Trojans have been presented and a comprehensive solution is yet to be developed. Trojan prevention methods have also been explored to ensure hardware security. This paper presents a new technique for HT prevention in which attackers are deprived of the resources to route their Trojans and connect them to the active region of the chip. In the proposed solution, the empty space of the die is filled with polysilicon to block unauthorized die connection by attackers. This will deprive attackers of the routing resources to layout their Trojan circuitry. A readout circuit is used to determine that the polysilicon layer is intact, and it has not been tampered with. Simulation results indicate that with proper design, even a reduction of around 14.85 $\mu m^{2}$ polysilicon can be detected. This technique can ensure 100% utilization of the empty spaces in the polysilicon layer.