On the Difficulty of Inserting Trojans in Reversible Computing Architectures

Fabrication-less design houses outsource their designs to third-party foundries to lower fabrication cost. However, this creates opportunities for a rogue in the semiconductor foundry to introduce hardware Trojans, which stay inactive most of the time and cause unintended consequences to the system when triggered. Hardware Trojans in traditional CMOS-based circuits have been studied, and Design-for-Trust (DFT) techniques have been proposed to detect them. Different from traditional circuits in many ways, reversible circuits implement one-to-one input/output mappings. In this paper, we investigate the security implications of reversible circuits with a particular focus on the susceptibility to hardware Trojans. To this end, we consider reversible functions implemented using reversible circuits as well as irreversible functions embedded in reversible circuits.