A Response-Nonlinearized DEMUX-TDC PUF for Resistance Against Modeling Attacks and Secure Authentication Protocols

As a critical hardware security primitive for the authentication within the Internet of Things (IoT), the physical unclonable function (PUF) represents an innovative security design paradigm for integrated circuits. However, the linear challenge-response mapping of the arbiter PUF (APUF) and variants render these structures more susceptible to modeling attacks due to their delayed linear structure. In this article, we propose a nonlinearized demultiplexer time-to-digital converter (DEMUX-TDC) PUF. This PUF uses a quantized delay difference technique to alter the traditional response generation mechanism, demonstrating robust resistance against modeling attacks. First, the proposed PUF employs a segmented APUF variant structure configured in both front and back segmented modes to generate a source of delay difference entropy. Additionally, the scheme incorporates a multilayer differential tapped TDC circuit to quantize the delay differences into digital codes, followed by a linear feedback shift register (LFSR) to obfuscate the final output response. We further propose a highly secure mutual authentication protocol based on reconfigurable PUF, by leveraging the characteristics of front and back segments of the PUF’s challenge. Evaluation of the proposed scheme on the implementation of Xilinx Virtex-7 and Spartan-6 field-programmable gate array (FPGA) demonstrates that the uniqueness and uniformity can reach ideal value, in the condition of prediction accuracy across six modeling attacks remaining around 50%.