Reliability and Uniformity Enhancement in 8T-SRAM based PUFs operating at NTC

Abstract

SRAM-based PUFs (SPUFs) have emerged as promising security primitives for low-power devices. However, operating 8T-SPUFs at Near-Threshold Computing (NTC) realm is plagued by exacerbated process variation (PV) sensitivity which thwarts their reliable operation. In this paper, we demonstrate the massive degradation in the reliability and uniformity characteristics of 8T-SPUF. By exploiting the opportunities bestowed by schematic asymmetry of 8T-SPUF cells, we propose biasing and sizing based design strategies. Our techniques achieve an immense improvement of more than 55% in the percentage of unreliable cells and improves the proximity to ideal uniformity by 82%, over a baseline NTC 8T-SPUF with no enhancement.