## 1 Introduction  
In today's digital age of interconnection, technology plays a significant role in transforming and affecting the daily lives of individuals in all dimensions, including traveling, shopping, and household electronics. There are many changes around us because of technology. Sophisticated sensors are embedded in many of the objects that surround us. Each sensor conveys crucial data that allow us to understand the functioning and interaction of these things. By 2025, it is estimated that the number of Internet of Things (IoT) devices will increase to more than 64 billion, approximately eight times the Earth's human population [1]. The IoT is a system of interconnected computing devices [2] that can transfer data (by sensing/acquiring) without human intervention. Unique identifiers are used to distinguish IoT devices. The IoT has revolutionized lives by enabling individuals and businesses to work more intelligently with enhanced control. It automates processes and significantly reduces labor costs and human errors. Nevertheless, challenges persist when deploying IoT networks. At the forefront of these challenges is the conundrum posed by multiple, heterogeneous IoT frameworks and existing standards. This intricacy necessitates a clarion call for enhanced standardization and a re-evaluation of compliance in device development [3]. The second challenge emanates from the ubiquity of miniature sensors and microcontrollers, defaulting to an \"ON\" state, potentially laying the groundwork for unauthorized access. However, the paramount concern lies in the realm of security and privacy, where IoT-sensitive data become vulnerable to the prying eyes of intruders and hackers [4]. The specer of data leakage looms large, with attacks stemming from impersonation and interceptions. Impersonation involves hackers masquerading as authorized users, while interception entails seizing communication channels to pilfer sensitive data, exemplified by a hacker infiltrating an intelligent home IoT application to steal personal information. Moreover, identification, authentication, encryption, confidentiality, jamming [5], cloning [6], hijacking [7], and privacy are among the IoT security challenges. Several systems employ encryption to secure their messages from being intercepted by hackers. To counteract these threats, encryption becomes the linchpin of IoT security, with cryptographic approaches serving as the vanguard. While encryption fortifies message security, its efficacy is not absolute. Malevolent third parties can still dispatch encrypted packets over the network [8], laying bare the need for additional protective measures. Authentication mechanisms emerge as a potent shield [9], with studies [10; 11] and proposals abounding to authenticate users or devices within the IoT ecosystem. One of the technologies adopted to protect IoT devices is PUFs. A PUF is a form of hardware that embraces challenge-response authentication [12]. It changes the input challenge into an output response with the help of a physical system. The scheme adopted to calculate the answer is designed to be exact to the hardware instance (unique) and cannot be replicated (unclonable). PUF authentication is based on users and devices. There are four different types of user authentication (password, token, and biometrics--hard and soft), the machines are cryptographic [13], and the PUFs have authentication protocols. The benefits of PUFs make them good candidates for IoT applications and systems. This paper embarks on a comprehensive exploration of PUFs in the context of IoT security. Building upon prior reviews, we delve into the characteristics, classifications, and relationships of various PUF technologies. A survey scrutinizes low-power System-on-Chip (SoC) designs, illuminating suitable hardware defenses in mobile and embedded systems operating under power constraints [14]. A retrospective analysis of proposed PUFs between 2001 and 2014 uncovers security issues, motivating further research to bolster PUF strength.