Design of Gas Sensors-Based PUF for Internet of Things Security

In the Internet of Things (IoT) systems, sensor nodes often have limited resources, such as weak computational capabilities, small storage space, and low battery capacity, and are susceptible to various network attacks. To enhance the security of sensor nodes, this article proposes the development of gas sensors using TiO2–ZnO nanofibers, innovatively leveraging the physical unclonable output response [physical unclonable function (PUF)] generated by the unavoidable random process variations introduced during the fabrication of semiconductor gas sensor arrays. Response data from the TiO2–ZnO gas sensors were collected under different concentrations of target gases and varying operating voltages. To improve data stability and reliability, the median averaging filter method was combined with a multibit balancing algorithm, ultimately producing a 128-bit PUF response. The proposed PUF was evaluated for security and reliability, with a uniqueness of 49.6%, a randomness of 98.6%, and a reliability of 97%. The results demonstrate that the PUF exhibits strong resistance to attacks and interference, providing secure and reliable identity authentication and key management services for IoT nodes.