A secure camouflaged logic family using post-manufacturing programming with a 3.6GHz adder prototype in 65nm CMOS at 1V nominal V<inf>DD</inf>

Abstract

With the continued globalization of the IC manufacturing supply chain, securing that supply chain is becoming increasingly difficult and this opens the door to a myriad of security threats such as unauthorized production, counterfeiting, IP theft, and hardware Trojan Horses. A parallel and related threat is posed by advanced reverse engineering capabilities, such that even chips manufactured at the most advanced technology nodes can be de-layered, imaged, and analyzed [1]. While various manufacturing methodologies and camouflaged gates have been proposed, none fully address these threats, especially in combination. To address these concerns, we use post-manufacturing programmable camouflaged logic topology to simultaneously obscure the design IP from the manufacturer as well as combat reverse engineering. The basis of the design is a threshold-voltage-defined (TVD) logic gate topology that solely uses different threshold voltage implants to determine the logic gate function [2]. Every gate has an identical physical layout and is post-manufacturing programmed with different threshold voltages for different Boolean functions using intentional directed hot-carrier injection (HCI). Similar intentional HCI techniques have previously been used to enhance SRAM margins, boost PUF reliability, and build TRNGs [3][4]. The design is fully compatible with standard CMOS logic processes, requiring no special layers, structures, or process steps.