Physical Unclonable Functions (PUFs) are hardware-based unique and irreproducible keys that can be used for authentication and encryption. We show that robustly secure PUFs can be easily manufactured by inscribing random gratings in optical fibers.
Physical Unclonable Functions (PUFs) are physical devices exploiting intrinsic randomness through the fabrication process that can be used for authentication and secure key generation. In this article, we describe a novel weak PUF architecture based on the inscription of random gratings in an optical fiber, which can be easily interrogated by a commercial instrument due to the enhanced backscatter. With PUF lengths of only 40 mm, we show that the false positive and false negative probabilities can reach below 10−27. We also describe a temperature and strain compensation algorithm to mitigate environmental fluctuations. Furthermore, we describe an alternative technique which increases the number of bits used for digitizing the PUF's signature, thus significantly decreasing the false identification probabilities by almost two orders of magnitude.
Abstract A physical unclonable function (PUF) device leverages manufacturing randomness to generate a unique fingerprint for secure authentication, encryption, and counterfeit prevention. Optical PUFs (OPUFs) have gained prominence due to their strong security, light‐based challenge‐response mechanisms, and potential for quantum‐secure encryption. These devices have promising applications for hardware security, authentication, cryptographic key generation, and anti‐counterfeiting measures across multiple industries. This review enlightens the diverse material platforms used for OPUFs, ranging from fiber optics and liquid crystals to advanced semiconductor nanocrystals and plasmonic metasurfaces, each offering distinct optical characteristics that impact security strength. While no single material system dominates the field, hybrid and multi‐model approaches integrating low‐dimensional materials are being explored to enhance reliability and scalability. Finally, the challenges and future perspectives are outlined, including adaptive OPUFs architectures, utilizing artificial intelligence (AI) for challenge‐response generation, and their integration into quantum communication networks, highlighting how next‐generation semiconductor materials can further advance OPUFs technologies.
Because of advancements in digital communication and associated technology, security and privacy have become crucial. Physical Unclonable Function (PUF) is one of the promising security solutions due to their adaptability, reliability, and secure nature. PUFs are unique identifiers that can be presented in many forms due to their unique structure and application. However, their application might be limited due to the reliability and fabrication process. Hence, a new PUF is proposed in this study, which comprises a semi-distributed fiber optic device. The proposed solution can overcome reliability concerns based on the unique behavior of biosensors and offers a simple fabrication process. Based on the random information of the physical characteristics, Physical Unclonable Functions has demonstrated potential for secure device authentication. This thesis describes the design, implementation, and evaluation of semi-distributed fiber optic devices as robust PUFs. Using intrinsic variability of fiber optic interferometric configurations, each device produces a unique spectrum showing good intra-device repeatability and high inter-device differentiation. Experimental validation of spectral reflectivity measurements confirms low internal variability, crucial for reliable authentication. In addition to these correlations, this research shows extensive simulations, allowing us to thoroughly analyze device uniqueness and stability, across a broad range of environmental scenarios. The proposed semi-distributed type of the fiber optic PUFs is promising solutions for secure and scalable authentication in applications that require high levels of security and integrity. This study represents a step towards the practical deployment and enhancement of fiber-optic PUF solutions into secure systems verification.
Quantum Physical Unclonable Functions (QPUFs) offer a physically grounded approach to secure authentication, extending the capabilities of classical PUFs. This review covers their theoretical foundations and key implementation challenges—such as quantum memories and Haar‐randomness—, and distinguishes QPUFs from Quantum Readout PUFs (QR‐PUFs), more experimentally accessible yet less robust against quantum‐capable adversaries. A co‐citation‐based selection method is employed to trace the evolution of QPUF architectures, from early QR‐PUFs to more recent Hybrid PUFs (HPUFs). This method further supports a discussion on the role of information‐theoretic analysis in mitigating inconsistencies in QPUF responses, underscoring the deep connection between secret‐key generation and authentication. Despite notable advances, achieving practical and robust QPUF‐based authentication remains an open challenge.
Physical unclonable functions (PUFs), physical objects that are practically unclonable because of their andom and uncontrollable manufacturing variations, are becoming increasingly popular as security primitives and unique identifiers in a fully digitized world. One of the central PUF premises states that both friends and foes, both legitimate manufacturers and external attackers alike, cannot clone a PUF, producing two instances that are the same. Using the latest nanofabrication techniques, we show that this premise is not always met: We demonstrate the possibility of effective PUF duplication through sophisticated manufacturers by producing 63 copies of a non-trivial optical scattering structure which exhibit essentially the same scattering behavior. The remaining minuscule differences are close to or below noise levels, whence the duplicates have to be considered fully equivalent from a PUF perspective. The possibility for manufacturer-based optical PUF duplication has positive and negative consequences at the same time: While fully breaking the security of certain schemes, it enables new applications, too. For example, it facilitates unforgeable labels for valuable items; the first key-free group identification schemes over digital networks; or new types of encryption/decryption devices that do not contain secret keys.