A 354F² Leakage-Based Physically Unclonable Function With Lossless Stabilization Through Remapping for Low-Cost IoT Security

A leakage-based physically unclonable function (PUF) is proposed to provide cost-effective security for Internet of Things (IoT) devices. By exploiting the exponential dependence of subthreshold leakage current on a transistor's threshold voltage variations, a response key bit is generated with only 354F2 silicon area. Moreover, to improve stability without discarding challenge-response pairs (CRPs), a novel lossless stabilization scheme called “remapping” is proposed. The proposed leakage-based PUF exhibited a 3.87% native unstable bit ratio (UBR) and 0.426% native bit error rate (BER). With the proposed remapping and 11-bit temporal majority voting applied, the BER and UBR are significantly improved to 47 and 538 ppm, respectively, achieving stability as high as a conventional trimming approach without any key losses.