Physical unclonable function (PUF) is a promising hardware security primitive that can generate a unique secret key peculiar to each chip by extracting the differences of non-reproducible manufacturing variations for the same implementations. Although there are several types of PUF designs and structures, ring oscillator (RO) PUF is one of the most prominent PUFs due to its straightforward implementation and remarkable performance. However, the traditional RO-PUF does not support large sizes of input/output combinations or challenge-response pairs (CRPs), as it is called in the scope of PUFs. Consequently, RO-PUF is more vulnerable to adversary attacks which can reveal the PUFs’ CRPs using a machine learning approach. Increasing the size of RO-PUF's CRPs requires a high increase in the circuit size leading to unacceptable area overhead for lightweight applications. The primary technique used to increase RO-PUF CRPs’ size without increasing the size of the required hardware is to develop a configurable ring oscillator (CRO) PUF. In this paper, we propose a configurable logic unit (CLU) that can be utilized to build a low-hardware CRO-PUF. The proposed CLU consists of a 1-XOR gate and a 1-XNOR gate. Building a CRO-PUF using the proposed CLU dramatically increases the CRPs size while minimizing the required hardware. The proposed CRO-PUF achieves excellent evaluation results, with measured uniqueness of 50.1 %, uniformity of 49.45 %, and reliability of 98.33 %. These values are in close proximity to the ideal targets of 50 % for uniqueness and uniformity, and 100 % for reliability

物理不可克隆函数（PUF）是一种很有前途的硬件安全原语，它可以通过提取相同实现的不可复制制造变化的差异来生成每个芯片特有的唯一密钥。尽管 PUF 设计和结构有多种类型，但环形振荡器 (RO) PUF 因其简单的实现和卓越的性能而成为最著名的 PUF 之一。然而，传统的 RO-PUF 不支持大尺寸的输入/输出组合或挑战响应对 (CRP)，正如 PUF 范围内所称的那样。因此，RO-PUF 更容易受到对手的攻击，这些攻击可以使用机器学习方法揭示 PUF 的 CRP。增加 RO-PUF 的 CRP 尺寸需要大幅增加电路尺寸，从而导致轻量级应用的面积开销不可接受。用于在不增加所需硬件大小的情况下增加 RO-PUF CRP 大小的主要技术是开发可配置环形振荡器 (CRO) PUF。在本文中，我们提出了一种可配置逻辑单元（CLU），可用于构建低硬件 CRO-PUF。所提出的 CLU 由一个 1-XOR 门和一个 1-XNOR 门组成。使用所提出的 CLU 构建 CRO-PUF 显着增加了 CRP 的大小，同时最大限度地减少了所需的硬件。所提出的CRO-PUF取得了优异的评价结果​​，测量的唯一性为50.1%，均匀性为49.45%，可靠性为98.33%。这些值非常接近 50% 的唯一性和一致性以及 100% 的可靠性的理想目标