MWA Skew SRAM Based SIMPL Systems for Public-Key Physical Cryptography

SIMulation Possible, but Laborious (SIMPL) systems are a novel cryptographic concept for physical cryptography that have been suggested in recent years. They can potentially solve inherent vulnerabilities of conventional public-key cryptography that is based on unproven mathematical hypotheses. The security of SIMPL systems rests on their physical unclonability and on the runtime difference between the real-time behavior of the unique SIMPL system and any adversarial simulation or emulation of it. One first circuit-based realization of SIMPL systems via so-called skew SRAMs has previously been discussed in the literature. This paper presents an approach to enhance the security of skew SRAM based SIMPL systems by introducing more complicated and parallel computing behavior taking place in the skew SRAM, which we call multiple-wordline-activation (MWA) skew SRAM. Simulations of the MWA skew SRAM show expected behavior complexity that can be taken advantage of in SIMPL systems to amplify the speed advantage over emulators (functional physical clones) or simulators (digital clones), which plays a key role in the security of SIMPL systems.