Integrated circuit anti-counterfeiting based on optical physical unclonable functions (PUFs) plays a crucial role in guaranteeing secure identification and authentication for Internet of Things (IoT) devices. While considerable efforts have been devoted to exploring optical PUFs, two critical challenges remain: incompatibility with the complementary metal-oxide-semiconductor (CMOS) technology and limited information entropy. Here, we demonstrate all-silicon multidimensionally-encoded optical PUFs fabricated by integrating silicon (Si) metasurface and erbium-doped Si quantum dots (Er-Si QDs) with a CMOS-compatible procedure. Five in-situ optical responses have been manifested within a single pixel, rendering an ultrahigh information entropy of 2.32 bits/pixel. The position-dependent optical responses originate from the position-dependent radiation field and Purcell effect. Our evaluation highlights their potential in IoT security through advanced metrics like bit uniformity, similarity, intra- and inter-Hamming distance, false-acceptance and rejection rates, and encoding capacity. We finally demonstrate the implementation of efficient lightweight mutual authentication protocols for IoT applications by using the all-Si multidimensionally-encoded optical PUFs.
Integrated circuit anti-counterfeiting based on optical physical unclonable functions (PUFs) plays a crucial role in guaranteeing secure identification and authentication for Internet of Things (IoT) devices. While considerable efforts have been devoted to exploring optical PUFs, two critical challenges remain: incompatibility with the complementary metal-oxide-semiconductor (CMOS) technology and limited information entropy. Here, we demonstrate all-silicon multidimensionally-encoded optical PUFs fabricated by integrating silicon (Si) metasurface and erbium-doped Si quantum dots (Er-Si QDs) with a CMOS-compatible procedure. Five in-situ optical responses have been manifested within a single pixel, rendering an ultrahigh information entropy of 2.32 bits/pixel. The position-dependent optical responses originate from the position-dependent radiation field and Purcell effect. Our evaluation highlights their potential in IoT security through advanced metrics like bit uniformity, similarity, intra- and inter-Hamming distance, false-acceptance and rejection rates, and encoding capacity. We finally demonstrate the implementation of efficient lightweight mutual authentication protocols for IoT applications by using the all-Si multidimensionally-encoded optical PUFs.
The rapid expansion of the Internet of Things (IoT) has significantly raised concerns over secure identification and authentication of IoT devices. While physical unclonable function (PUF)-based anticounterfeiting cryptography shows promise, implementing multi-factor authentication (MFA) system with resource-constrained PUF device remains a significant challenge. Here, we demonstrate a multidimensional-encoded optical PUF fabricated with multi-color quantum dots (mQDs), resilient to machine learning attacks, for use in anticounterfeiting MFA. Randomly distributed mQDs in a periodic nanostructure fabricated via nanoimprint lithography generate spatially chaotic, unpredictable multiple security keys when ultraviolet (UV) light is only illuminated. Photoluminescence measurements revealed irregular mQD emission, where disordered distribution-induced Förster resonant energy transfer produces unpredictable color patterns. Our PUF-induced multiple keys were validated through advanced PUF metrics like uniformity, uniqueness, correlation factor, entropy, and even resilience to machine learning attack. We further demonstrate efficient implementation of a cryptography protocol with MFA system for IoT applications using mQDs-based optical PUFs. Material systems with physical unclonable functions (PUF) are needed for secure authentication. Here, a multidimensional-encoded optical PUF fabricated with multi-color quantum dots is demonstrated, for multi-factor authentication.
Physical Unclonable Functions (PUFs) are hardware security primitives whose inherent physical complexity can be exploited for secure authentication and cryptographic key generation. Silicon photonic devices, owing to their suitability for quantum and artificial intelligence applications alongside standard CMOS fabrication processes, constitute a highly promising substrate for integrated multifunctional PUFs. Despite the advanced security guarantees offered by quantum cryptographic protocols and the central role of silicon photonics in quantum technologies, quantum readout strategies based on single-photon states for photonic PUFs remain largely unexplored. In this work, we experimentally demonstrate a silicon nitride (SiN) programmable photonic Mach Zehnder interferometer mesh that implements a unitary transformation and operates as a PUF, whose secret physical signature arises from uncontrollable waveguide variations during fabrication. Using experimentally derived parameters from the SiN integrated mesh, we further introduce and numerically evaluate a quantum readout protocol that combines single-photon states with PUFs. Maximally mixed quantum states are employed to conceal the underlying unitary transformation from passive eavesdropping. Security against adversaries possessing devices fabricated under similar conditions is assessed, with authentication performance quantified through Monte Carlo analysis of the false acceptance and false rejection rates as a function of the number of detected events and corrected errors. The results indicate exceptional performance with equal error rates as low as 10 to the minus 14, highlighting the potential of quantum secure PUFs for high security authentication applications.
With the rapid expansion of digital communication and the Internet of Things (IoT), hardware-level security and anti-counterfeiting technologies have become increasingly important. Traditional cryptographic systems depend on mathematically generated keys, which are vulnerable to duplication and physical attacks. In contrast, Physical Unclonable Functions (PUFs) utilize inherent physical randomness to produce unique, unpredictable responses, offering a hardware root of trust for secure authentication. Among various PUF implementations, optical PUFs (O-PUFs) have attracted attention due to their high entropy density, non-contact readout, and immunity to electromagnetic interference. These systems exploit light–matter interactions, such as scattering, reflection, and emission to generate random optical fingerprints. In recent years, photoluminescent (PL) materials have emerged as promising candidates for constructing material-based optical PUFs. Their intrinsic emission randomness, strong optical signals, and tunable luminescence enable secure encoding without complex nanofabrication. Materials such as perovskite quantum dots and lanthanide-based metal–organic frameworks (MOFs) combine high photoluminescence efficiency, environmental stability, and low-cost processability, making them ideal for scalable optical authentication applications. This thesis explores the development and performance evaluation of photoluminescent based PUFs for optical security and anti-counterfeiting. Three types of luminescent materials, namely perovskite quantum dots, lanthanide-based MOFs, and intermolecular charge-transfer (CT) complexes are qualitatively analyzed as potential optical PUF platforms. A particular focus is placed on the statistical evaluation of Terbium-based MOFs (Tb-MOFs) and CT complexes. For Tb-MOFs, two entropy sources are examined: the spatial distribution of MOF microstructures and the randomness in PL intensity. Similarly, CT complexes are evaluated based on their disordered geometric topology. Standardized image processing, including optical imaging, grayscale conversion, and binarization, is employed to extract PUF features. Quantitative metrics such as uniqueness, reliability, and encoding capacity are analyzed. The results demonstrate that both Tb-MOF and CT-based systems achieve high encoding capacity and stable reproducibility within a sub-millimeter scale. This study validates the feasibility of luminescent materials as robust optical PUFs and provides a foundation for scalable, photostable, and intelligent optical authentication systems
Quantum dots (QDs) have garnered significant attention for their unique size-dependent optical and electronic properties, enabling their widespread use in applications ranging from high-efficiency photovoltaics and light-emitting diodes to biomedical imaging and quantum computing. Their tunable emission, high photo-stability, and ease of surface modification make them ideal candidates for precision nanotechnology applications. In this work, we explore a novel and rapidly emerging application of QDs in hardware security through the development of Quantum Dot-based Physical Unclonable Functions (QD-PUFs). Unlike conventional security paradigms, QD-PUFs leverage the intrinsic physical randomness of QD-based nanostructures to generate challenge-response pairs with superior uniqueness, reliability, and robustness. We review the integration of QDs into PUFs, beginning with their material properties and extending to entropy sources arising from synthesis and fabrication, surface and encapsulation effects. A comparative analysis of different readout mechanisms and related applications underscores the unique encoding capacity and security potential of QD-based systems. By demonstrating their feasibility for scalable, high-security applications, this study underscores the transformative impact of QDs in next-generation authentication and anti-counterfeiting technologies.
As an anti-counterfeiting technology, physical unclonable function (PUF) is irreplaceable in addressing security risks in the Internet of Things. However, limited by the fixed structural shape, PUF security cannot be further improved. Here, we present a 5D spin-PUF with three sensing effects and two spatial parameters as encoding parameters. The free transformation of the spin state is regulated for dynamic anti-counterfeiting. Fabricated by the self-developed laser-induced technology, the 5D coding base units are composed with random crystal direction, height, and concentration of SiC nanocrystals with spin structures. Spin states are manipulated by temperature, magnetic fields, and microwaves as three additional dimensions. The number of challenge-response pairs increases exponentially to 4,097 with an encoding capacity of 10 27 , 310 , 000 . With an excellent Hamming distance and low autocorrelation coefficient, the recognition accuracy reaches more than 94% using DenseNet. Additionally, we demonstrate unique real-time anti-counterfeiting of product state information. It could potentially be a next-generation security strategy.
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.