Traditional Physical Unclonable Functions Research Articles

Near-Infrared Circularly Polarized Luminescent Physical Unclonable Functions.

Distinguished from traditional physical unclonable functions (PUFs), optical PUFs derive their encoded information from the optical properties of materials, offering distinct advantages, including solution processability, material versatility, and tunable luminescence performance. However, existing research on optical PUFs has predominantly centered on visible photoluminescence, while advanced optical PUFs based on higher-level covert light remain unexplored. In this study, we present optical PUFs based on the utilization of the covert light of near-infrared circularly polarized luminescence (NIR-CPL). This interesting property is achieved by incorporating Yb-doped metal halide perovskite nanocrystals (Yb-PeNCs) possessing NIR emission property into chiral imprinted photonic (CIP) films. By employing a solvent immersion method, we successfully integrated Yb-PeNCs into these CIP films, thereby creating an optically unclonable surface. The resulting NIR-CPL emission adds a layer of advanced security to the optical PUF systems. These findings underscore the potential of solution-processable chiral films to play a pivotal role in advancing the next generation of PUFs.

Voxelated opto-physically unclonable functions via irreplicable wrinkles

The increased prevalence of the Internet of Things (IoT) and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures. In response to these challenges, physical unclonable functions (PUFs) have emerged as promising solution, offering a highly secure method to generate unpredictable and unique random digital values by leveraging inherent physical characteristics. However, traditional PUFs implementations often require complex hardware and circuitry, which can add to the cost and complexity of the system. We present a novel approach using a random wrinkles PUF (rw-PUF) based on an optically anisotropic, facile, simple, and cost-effective material. These wrinkles contain randomly oriented liquid crystal molecules, resulting in a two-dimensional retardation map corresponding to a complex birefringence pattern. Additionally, our proposed technique allows for customization based on specific requirements using a spatial light modulator, enabling fast fabrication. The random wrinkles PUF has the capability to store multiple data sets within a single PUF without the need for physical alterations. Furthermore, we introduce a concept called ‘polyhedron authentication,’ which utilizes three-dimensional information storage in a voxelated random wrinkles PUF. This approach demonstrates the feasibility of implementing high-level security technology by leveraging the unique properties of the rw-PUF.

Unclonable Micro-Texture with Clonable Micro-Shape towards Rapid, Convenient, and Low-Cost Fluorescent Anti-Counterfeiting Labels.

An ideal anti-counterfeiting label not only needs to be unclonable and accurate but also must consider cost and efficiency. But the traditional physical unclonable function (PUF) recognition technology must match all the images in a database one by one. The matching time increases with the number of samples. Here, a new kind of PUF anti-counterfeiting label is introduced with high modifiability, low reagent cost (2.1 × 10-4 USD), simple and fast authentication (overall time 12.17 s), high encoding capacity (2.1 × 10623 ), and its identification software. All inorganic perovskite nanocrystalline films with clonable micro-profile and unclonable micro-texture are prepared by laser engraving for lyophilic patterning, liquid strip sliding for high throughput droplet generation, and evaporative self-assembling for thin film deposition. A variety of crystal film profile shapes can be used as "specificator" for imagerecognition, and the verification time of recognition technology based on this divide-and-conquer strategy can be decreased by more than 20 times.

Study on the Physical Unclonable Function of the Reliable Information Entropy Extracted by the Frequency Characteristic of Oscillating Ring

Considering the problem of information entropy being low and easily disturbed by environmental factors in the traditional Physical Unclonable Function (PUF), a PUF scheme is designed to generate multiple stable information entropy. By analyzing the frequency data generated by the ring oscillator on the FPGA, the feature bits representing the characteristics of the ring are extracted from each ring as information entropy. By studying the temperature characteristics of the inverter, a new oscillating ring is formed by the current hungry inverter and the conventional inverter to reduce the influence of temperature on the reliability of the generated information entropy. Through Cadence IC simulation and experiments on zynq7000 series FPGA development platform, the results show that the improved PUF structure can generate more information entropy with the same number of oscillatory rings, and its reliability and uniqueness are improved.

A Physical Unclonable Function Using a Configurable Tristate Hybrid Scheme With Non-Volatile Memory

The physical unclonable function (PUF) is a promising low-cost hardware security primitive. Recent advances in nanotechnology have provided new opportunities for nanoscale PUF circuits. The resistive random access memory (RRAM) is extensively used in nanoscale circuits due to its low cost, non-volatility and easy integration with CMOS. This paper proposes a novel tristate hybrid PUF (TH-PUF) design based on a one-transistor-one-RRAM (1T1R) cell; this cell can be configured into two weak PUFs and a strong PUF using few control signals. To assess the proposed PUF design, a compact RRAM model at UMC 65 nm technology is employed. Simulation results show that the proposed TH-PUF achieves good uniqueness, reliability as well as a higher gate usability compared with an entire CMOS PUFs. The number of challenge response pairs (CRPs) of the proposed TH-PUF is larger than other RRAM-based PUFs. Moreover, the TH-PUF is more resistant to a modeling machine learning attack than traditional PUF designs.

Advances in superlattice cryptography research

One of the widely-known opinions in modern cryptography is that the security of a cryptosystem depends on the security of key. Therefore, key management is the foundation engineering of information security field and its corresponding technical level plays a decisive role in the security and efficiency of entire cryptosystem. Key generation and key distribution are two bottleneck problems of key management which make practical cryptosystem complex and costly to make up for the defects of security. Cryptographic techniques based on physical methods are introduced to generate and distribute secure key which greatly reduce the risk of key management than the traditional techniques based on mathematical methods. Currently, it is a popular research direction to solve cryptographic problems with physical entities such as quantum cryptography, physical unclonable function (PUF), etc. Superlattice cryptography is a brand-new cryptographic technology based on semiconductor superlattice device physics which was developed upon the innovative works of superlattice material electronic characteristics researches and is gaining increasing international influence. Superlattice device taps into the random variation during fabrication processes, therefore the secret is extremely difficult to predict or extract. Moreover, once matched superlattice device pairs are produced, anyone cannot obtain or duplicate, including the original producer with complete set of equipment. Superlattice devices can be used similar to traditional PUF hardware that extract secrets from physical characteristics. It takes full advantages of the internal security of hardware to establish new cryptographic mechanism and application pattern with superlattice PUF devices. On one hand, with the theoretical framework of PUF being introduced to superlattice research, superlattice cryptography becomes a cross-discipline that puts forward a new concept of hardware cryptography and develops PUF theory, and leads to a new research direction for cryptography. On the other hand, superlattice PUF pairs provide a feasible approach to the key management that has long obstructed the information security engineering. This review briefly introduces the origin and development of superlattice cryptography along with current state-of-the-art advances of practical technologies including physical random number generation technology and superlattice key distribution technology. Based on the spontaneous chaotic oscillation of GaAs/Al0.45Ga0.55As semiconductor superlattice, high-quality, efficient and stable physical random number technology was developed, which has laid a good foundation for the subsequent research and development of superlattice cryptography. The superlattice devices were incorporated into the framework of PUF theory in cryptography, and soon afterwards chaos synchronization between unclonable matched superlattice pairs was discovered, based on which a long-haul public-channel secure key distribution was experimentally demonstrated with an unconditional security key distribution protocol with self-authentication capability created. The theoretical significance and application potential of superlattice cryptography have been recognized by cryptographers, microelectronic experts and information security engineers. Despite of academic progress made and innovative technologies exploited in several aspects of superlattice cryptography, our research method and relevant technical route are still quite simple and limited. In the following research, the physical mechanism related to the security properties of superlattice cryptography is urgently needed to be further analyzed, methods to evaluate the security properties of superlattice cryptography devices are going to be systematically developed and a formal proof of the protocol design and security model of the superlattice cryptography will be built. The future works are expected to establish superlattice cryptography as a fundamental information security technology which is fully independently controllable from fundamental theory through device manufacturing technology all the way to application technology in our country.

Voice-Based User-Device Physical Unclonable Functions for Mobile Device Authentication

In this paper, a novel voice-based User-Device (UD-) physical unclonable function (PUF) is demonstrated. In traditional PUFs, variability of challenge-response pairs (CRPs) only comes from physical randomness of silicon. Recently, a new type of PUF, touch screen-based UD-PUF was proposed, which entangles human user biometric variability with the silicon variability. Any silicon-based mobile device sensor which is a UI element can potentially seed such a UD-PUF. Having multiple orthogonal sensor space UD-PUFs helps robustness. If one UD-PUF behaves poorly in certain environmental conditions, another one might behave well. In voice UD-PUF, challenges are single words chosen by the user. The user speaks the challenge word into the microphone of the mobile device. The speech has natural human biometric variability. Raw microphone output data of analog to digital converter (ADC) also reflects the silicon variability. This voice microphone data sequence can be quantized into a binary sequence leading to a PUF—a physical randomness derived, unclonable function. To ensure reproducibility, a background noise reduction algorithm, a statistical error correction, and a frequency domain canonical representation are utilized. Both variability and reproducibility of this voice UD-PUF are evaluated. Several authentication algorithms are proposed in this paper. Pixel-matching authentication algorithm provides an average 15.33% false positive rate and an average 12.30% false negative rate while frame-count authentication algorithm provides an average 6.27% false positive rate and an average 13.23% false negative rate. For variability, we show 250+ bits Hamming distance, on average, between 512 bits binary responses of different (user, device, challenge) combinations. We also assess the pseudorandom number generation properties of voice UD-PUF by putting its binary responses through UMontreal TESTU01 suite of tests. The best voice UD-PUF algorithm passed all 26 randomness tests.