Transformer PUF : A Highly Flexible Configurable RO PUF Based on FPGA

Physical unclonable function (PUF) is a promising security primitive for IP protection and user authentication. As there are plenty of reconfigurable resources in a field programmable gate array (FPGA), configurable ring oscillator (CRO) PUF is one of the most hardware efficient PUF designs. Previous CRO PUF designs have relatively improved the yield of challenge and response pairs (CRPs). In this paper, a highly flexible CRO PUF based on FPGA, defined as Transformer PUF, is proposed. The proposed PUF design, which has multiple reconfigurability from XOR gates and multiplexers, can be deformable between different CRO PUFs. Compared with the traditional CRO PUFs, it is more resistant to two common machine learning attack techniques, logistic regression (LR) and covariance matrix adaptation evolutionary strategies (CMA-ES), with a small sample set size. Moreover, the Transformer PUF achieves the highest hardware efficiency among CRO PUFs. The results of the experiment carried out on Xilinx Artix-7 development board demonstrate that Transformer PUF has a good uniqueness of 49.44% and a high reliability of 98.12%.