TIMA-PUF: Time Measurement Based Arbiter PUF

Designing a reliable and lightweight Physical Unclonable Function (PUF) is of prior importance in the context of hardware security. In this paper, a new variant of an arbiter PUF is proposed. Unlike the classical arbiter PUF that only compares the delay of two symmetrical paths, we propose to measure the path propagation delays and returns the time difference. Such measurements enable the arbiter PUF to be used in conjunction with techniques such as filtering of unreliable or low-entropy challenges and, thus, improve the global PUF performances. This ability is obtained thanks to an asynchronous Time-To-Digital Converter (TDC), which allows the measurements of the path delays. The proposed PUF benefits from the strengths of a classical arbiter PUF, such as the ability to extract a large number of challenge-response pairs at high throughput while improving reliability and entropy. This new arbiter PUF has been implemented on an FPGA and the results show it can achieve almost ideal values for metrics such as uniqueness, reliability and uniformity, simply by filtering the most unreliable responses.