Leakage-based Strong PUF Operating at Ultra-Low Voltage Using a Leakage Control Approach
Shunkichi Hata, Kimiyoshi Usami · 2024
PUF (Physically Unclonable Function) utilizing the physical characteristics of semiconductors has been attracting an attention as the individual identification technology of LSI chips. This technology is expected to make it possible to authenticate genuine products and prevent the distribution of counterfeit products. On the other hand, when energy harvesting is used as a power source, the electromotive force of the energy harvester is small and ultra-low voltage operation is required. LRPUF (Leak Racing PUF) was proposed as a leakage based strong PUF composed of digital circuits. However, ultra-low voltage operation has not been reported with a proof of working in real silicon so far. In this paper, in order to improve the quality of LRPUF at ultra-low voltage, we propose a method to make it operate at ultra-low voltage. The voltage for leakage control (VLC) which controls the leakage current in the leakage generation circuit of the LRPUF is used to enable ultra-low voltage operation. The proposed LRPUF was fabricated in a 180nm CMOS bulk process and the measured results demonstrated that it properly operates at 0.4V. Measurements on 9 chips show Inter-HD of 40.1 %, Intra-HD of 2.72%, and Hamming Weight of 66.53%. The mesured energy dissipation per L-bit output is 18.75 [fJ/bit] and the area to one CRP is$\mathbf{ 1.51E-23[} F^2 / \mathbf{ CRP] }$.