Xilinx FPGA-based Ring Oscillator PUFs: Design Challenges and Solutions

The configurability and programmability features of the FPGA boards make it a preferred platform to implement vast IoT and embedded systems applications. However, FPGAs are vulnerable to different security issues such as unauthorized cloning, counterfeiting, or overbuilding the original systems. Therefore, there is an increasing demand for security solutions for FPGA-based systems, which may be used in device authentication and secret key generation. Physical unclonable functions (PUFs) have emerged as a low-cost, reliable countermeasure against different hardware security threats. Ring oscillator PUFs are well suited to be implemented on FPGA boards. Consequently, ring oscillator PUFs are widely used as security measures with FPGA-based IoT and embedded systems. Nevertheless, some challenges face the design of FPGA-based ring oscillator PUFs. Hence, this paper presents possible challenges that may face the design of an FPGA-based ring oscillator PUFs and the possible solution for each challenge. In addition, this study further discusses ways to improve the main performance metrics for the FPGA-based ring oscillator PUF, which are uniqueness, uniformity, and reliability.