Statistical RF/Analog Integrated Circuit Design Using Combinatorial Randomness for Hardware Security Applications

A true random number generator (TRNG) is essential to ensure information security for Internet of Things (IoT) edge devices. While pseudorandom number generators (PRNGs) have been instrumental, their deterministic nature limits their application in security-sensitive scenarios. In contrast, hardware-based TRNGs derived from physically unpredictable processes offer greater reliability. This study demonstrates a peripheral-free TRNG utilizing two cascaded three-stage inverters (TSIs) in conjunction with an XOR gate composed of monolayer molybdenum disulfide (MoS2) field-effect transistors (FETs) by exploiting the stochastic charge trapping and detrapping phenomena at and/or near the MoS2/dielectric interface. The entropy source passes the NIST SP800-90B tests with a minimum normalized entropy of 0.8780, while the generated bits pass the NIST SP800-22 randomness tests without any postprocessing. Moreover, the keys generated using these random bits are uncorrelated with near-ideal entropy, bit uniformity, and Hamming distances, exhibiting resilience against machine learning (ML) attacks, temperature variations, and supply bias fluctuations with a frugal energy expenditure of 30 pJ/bit. This approach offers an advantageous alternative to conventional silicon, memristive, and nanomaterial-based TRNGs as it obviates the need for extensive peripherals while harnessing the potential of atomically thin 2D materials in developing low-power TRNGs.

A reconfigurable PUF structure with dual working modes based on entropy separation model

This paper presents a novel approach to enhancing the security and reliability of drone communications through the integration of Quantum Random Number Generators (QRNG) in Frequency Hopping Spread Spectrum (FHSS) systems. We propose a multi-drone framework that leverages QRNG technology to generate truly random frequency hopping sequences, significantly improving resistance against jamming and interception attempts. Our method introduces a concurrent access protocol for multiple drones to share a QRNG device efficiently, incorporating robust error handling and a shared memory system for random number distribution. The implementation includes secure communication protocols, ensuring data integrity and confidentiality through encryption and Hash-based Message Authentication Code (HMAC) verification. We demonstrate the system’s effectiveness through comprehensive simulations and statistical analyses, including spectral density, frequency distribution, and autocorrelation studies of the generated frequency sequences. The results show a significant enhancement in the unpredictability and uniformity of frequency distributions compared to traditional pseudo-random number generator-based approaches. Specifically, the frequency distributions of the drones exhibited a relatively uniform spread across the available spectrum, with minimal discernible patterns in the frequency sequences, indicating high unpredictability. Autocorrelation analyses revealed a sharp peak at zero lag and linear decrease to zero values for other lags, confirming a general absence of periodicity or predictability in the sequences, which enhances resistance to predictive attacks. Spectral analysis confirmed a relatively flat power spectral density across frequencies, characteristic of truly random sequences, thereby minimizing vulnerabilities to spectral-based jamming. Statistical tests, including Chi-squared and Kolmogorov-Smirnov, further confirm the unpredictability of the frequency sequences generated by QRNG, supporting enhanced security measures against predictive attacks. While some short-term correlations were observed, suggesting areas for improvement in QRNG technology, the overall findings confirm the potential of QRNG-based FHSS systems in significantly improving the security and reliability of drone communications. This work contributes to the growing field of quantum-enhanced wireless communications, offering substantial advancements in security and reliability for drone operations. The proposed system has potential applications in military, emergency response, and secure commercial drone operations, where enhanced communication security is paramount.

The Internet of Things (IoT) now underpins critical systems like healthcare monitors, smart home, smart grids, automotive V2V & V2X networks, and industrial controls but it still relies on classical cryptography, whose security assumptions are vulnerable to quantum computers. A large quantum computer could run Shor’s algorithm to break RSA/ECC and use Grover’s algorithm to accelerate brute-forcing of symmetric keys, undermining the confidentiality and authentication of data in these IoT applications. Researchers have proposed quantum cryptographic solutions. Quantum key distribution (QKD) and quantum random number generators (QRNGs) exploit quantum mechanics to detect eavesdropping and deliver provably secure key material. For example, chip-scale QRNGs can be embedded in IoT sensors to generate true random keys, boosting resistance to brute-force attacks. These quantum techniques provide information-theoretic secrecy, for instance, QKD-generated keys have been used to authenticate smart-grid SCADA. However, most IoT devices are resource-constrained, making direct deployment of conventional QKD hardware challenging. Post-quantum cryptography (PQC) complements quantum methods by providing algorithms such as lattice-based, hash-based that resist quantum attacks on existing hardware. Standardized PQC can be deployed via software updates on legacy IoT nodes, enabling scalable and quantum-safe security within current constraints. Researchers are exploring lightweight PQC for connected cars and e-health sensors. Hybrid approaches combining QKD/QRNG with PQC offer a layered defense. Since QKD protocols are regarded as ‘future-proof’ and PQC standards mature, their combined use will be essential for robust, quantum-safe IoT security. Miniaturizing quantum components such as integrated QKD/QRNG modules and optimizing lightweight PQC schemes for low-power IoT devices are future research directions to secure IoT networks.

A TRNG (True Random Number Generator) is an important component for security in mobile computing and IoT. This paper presents an light-weight FPGA implementation of a previously proposed latch-based TRNG, while keeping the quality of generated random numbers. By accumulating the generated random numbers fifteen times with an XOR operation for each output word, the proposed TRNG with 16 latches passed the NIST SP 800-22 test suite, whereas the original TRNG required 248 latches. An important finding of this work is that the quality of random sequence is greatly improved by XOR-ing temporally interleaved series of bits.

The primary driving force for the introduction of alternative gate dielectrics in advanced complementary metal oxide semiconductor (CMOS) devices is the dramatic increase in direct tunneling that occurs when the SiO2 physical thickness is reduced to less than 3 nm. For example the direct tunneling current at an oxide bias of 1 V is approximately 10−2 A/cm2 for an oxide physical thickness of 2.0 nm, and increases approximately one order of magnitude for each additional decrease of 0.2 nm thereby placing significant limitations on the performance and reliability of CMOS field effect transistor (FET) devices and integrated circuits (ICs). If the limitations for direct tunneling leakage current are taken to be 1–5 A/cm2 for high performance devices, and <10−2 A/cm2 for mobile and low power devices, tunneling leakage limits SiO2 physical thickness reductions to ∼1–4 to 1.6 nm, and ∼2.0 nm, respectively. Since there is a linear scaling relationship between lateral in-plane device dimensions, and SiO2 physical and equivalent oxide thickness (EOT), these tunneling limitations have important implications for the ultimate decreases in device dimensions, and increases in device integration (1). One obvious solution is to replace SiO2 by alternative gate dielectrics that have higher dielectric constants, k, than the nominal value of ko = 3.9 ± 0.1 for SiO2, thereby increasing the physical thickness of the dielectric by the ratio of dielectric constants, k/ko, without reducing the gate dielectric capacitance, Cox. However, the very large decreases in tunneling currents anticipated by increases in physical thickness alone can be significantly mitigated by decreases in (i) the

Since the Internet of Things (IoT) will be entwined with everything we use in our daily life, the consequence of security flaws escalates. Smart objects will govern most of the home appliances and car engines yielding potential disaster scenarios. In this context, successful attacks could lead to chaos and scary scenarios (www.darkreading.com). Unprotected personal information may expose sensitive and embarrassing data to the public and attacks may threaten not only our computers and smart devices, but our intimacy and perhaps our lives too. Because persons and objects will be bonded with each other, user consent becomes critical. Therefore, thing, object, and user Identity will be the focus of future IoT security solutions, yielding a Trust, Security, and Privacy (TSP) paradigm, which may constitute the Achilles' heel of IoT. While security issues are quite straightforward, mainly from background knowledge, privacy issues are far more complex. Privacy constitutes a rather challenging task, even for the m...

With the widespread penetration of the Internet of Things in various fields, its secure communication issues have become a key factor restricting the further development of the Internet of Things. This study deeply analyzes the many challenges faced by secure communications in the Internet of Things, including security risks of IoT cards , difficulties at the device and network levels, etc. The role of key technologies such as identity authentication, encryption, security analysis and threat prediction in ensuring secure communications in the Internet of Things is elaborated in detail. At the same time, the development trend of secure communications in the Internet of Things is discussed, such as the gradual improvement of standards and specifications and the application prospects of new technologies in security protection. Finally, strategies for dealing with secure communications issues in the Internet of Things from the technical level, management and cooperation level are proposed, aiming to provide comprehensive reference and guidance for research and practice in the field of secure communications in the Internet of Things, and promote the healthy and sustainable development of the Internet of Things industry.

8 - Electromigration failure in nanoscale copper interconnects

Free form (physically flexible and stretchable) electronics can be used for applications which are unexplored today due to the rigid and brittle nature of the state-of-the-art electronics. Therefore, we show integration strategy to rationally design materials, processes and devices to transform advanced complementary metal oxide semiconductor (CMOS) electronics into flexible and stretchable one while retaining their high performance, energy efficiency, ultra-large-scale-integration (ULSI) density, reliability and performance over cost benefit to expand its applications for wearable, implantable and Internet-of-Everything electronics.

The rapid expansion of the Internet of Things (IoT) has introduced unprecedented cybersecurity challenges, as traditional cryptographic methods struggle to provide both efficiency and quantum resistance in resource-constrained environments. This research introduces Adaptive Quantum Cryptography (AQC), a novel security framework that integrates Quantum Key Distribution (QKD), Post-Quantum Cryptography (PQC), Quantum Random Number Generators (QRNGs), and AI-driven dynamic adaptation to safeguard IoT networks against evolving cyber threats. Unlike classical encryption techniques such as RSA and ECC, which are vulnerable to quantum attacks, AQC leverages quantum mechanical principles—such as superposition, entanglement, and the no-cloning theorem—to ensure provably secure key exchange and data encryption. The proposed AQC system dynamically adjusts cryptographic protocols based on real-time network conditions, computational resources, and threat intelligence, optimizing security without imposing excessive overhead. Experimental evaluations demonstrate that AQC achieves a 70% improvement in key exchange efficiency, a 50% reduction in computational load, and a 95% resilience rate against quantum attacks compared to conventional encryption methods. Additionally, the integration of QRNGs enhances cryptographic key entropy, while AI-driven anomaly detection enables proactive threat mitigation. This framework is particularly suited for next-generation IoT applications, including smart grids, autonomous vehicles, and industrial automation, where security, scalability, and energy efficiency are critical. By combining quantum-resistant algorithms with adaptive security mechanisms, AQC provides forward secrecy, resistance to quantum adversaries, and robust authentication, ensuring long-term protection for IoT ecosystems in the post-quantum era. The findings underscore AQC’s potential as a foundational security architecture for future quantum-safe IoT networks.

The explosive growth of Internet of Things (IoT) devices has demanded the urgency of robust data security to protect private information. The random numbers generated by pseudo‐random number generators (PRNGs) play a crucial role in cryptographic algorithms. However, these sequences have become increasingly predictable due to advances in computing power and machine learning. Therefore, the development of true random number generators (TRNGs), which exploit the intrinsic hardware‐level randomness as an entropy source, is important for future data security. In this study, we present TRNG circuits that harness the inherent stochasticity of a multilayer hBN volatile memristor. The fabricated device exhibits highly stable threshold switching with low set/hold voltages and a significantly high on/off ratio. We implement a spike generator by integrating the threshold switching memristor with passive components. Digitization with a fixed‐reference comparator directly converts output spikes into bitstreams that successfully pass NIST randomness tests without postprocessing. The practical utility of the TRNG is demonstrated through XOR‐based encryption and decryption of black‐and‐white and grayscale images, resulting in noise‐like encrypted data and perfect recovery of the originals using identical keys. These results establish 2D hBN‐based threshold switching memristors as compelling hardware entropy sources for secure, next‐generation electronic systems.

Security primitives ensure Internet of Things (IoT) security by generating stable keys from physically unclonable functions (PUFs) and unpredictable bitstreams from true random number generators (TRNGs). Considering the restricted resources on IoT motes, a promising design trend is to unify PUF and TRNG by sharing the same entropy source and multiplexing entropy extractor. Here, we report a unified PUF and TRNG chip based on a 28-nanometer embedded memristor with concealable ability. We use the memristor intrinsic FORMING condition variation and read current variation as entropy sources and design a compact on-chip entropy extractor that achieves a high throughput of 41.7 megabits per second with minimal area overhead of 0.291 MF2. To prevent PUF data leakage, we developed a concealment method, protecting data when idle and enabling recovery upon demand. Comprehensive testing shows the chip has excellent performance in randomness, reliability, lifetime, and stability, achieving a 3.82-fold throughput improvement over complementary metal-oxide semiconductor-based designs in authentication tasks.

A collaboration of US and Swedish researchers presents, for the first time, radio frequency (RF) reliability studies of fully integrated complimentary metal-oxide-semiconductor (CMOS) radio frequency integrated circuits (RFICs), important for designing next generation wireless communication applications, especially those that are based on ultra-thin flexible packages. Mitra et al. have a wide spread of research areas, including such topics as communications radar, hand-held medical scanners and portable weapon scanning technology. It is, however, their research into CMOS RFICs that lead to the present paper. Mastery of CMOS technology, with its small chip size, is thought to be crucial for the continued miniaturisation of circuits, with the world of nanoelectronics providing a potential gateway to the next generation of highly integrated multifunctional devices, circuits and systems. The Radio Frequency Integrated Circuits (RFIC) Lab members at North Dakota State University. (From Left) Arka Biswas, Chitralekha Biswas, Dipankar Mitra (in the back), and Babak Hamidi. RFIC Characterisation Set-up at NDSU. The ‘thinning-down’ of integrated circuits is one step towards mastering CMOS technology, with thinner and more lightweight circuitry providing more efficient and cost-effective solutions for various applications, including wireless communications, wearable and flexible electronics and Internet of Things (IoT) devices. One of the biggest challenges for realisation of flexible and ultra-thin ICs is the effect die-substrate thinning has on the RF performance of the IC. It was this problem that triggered Mitra et al. into producing the RF reliability studies presented in Electronics Letters. Thinning of the die-substrate, the small block of semiconducting material upon which a circuit is built, is one of the main contributors to performance degradation for RFICs, whilst also being the most important for producing thinner and more flexible circuitry. In their work, Mitra et al. use a voltage-controlled oscillator (VCO) to measure the effects of die-substrate thickness on the RF performance of the IC, including frequency range, RF output power variation, phase noise variation and DC parameters. The usual thickness of die-substrate for CMOS circuits as between 250–300 micrometres. Mitra et al. used a 250 µm thickness VCO as a test case, and then thinned down the die-substrate to 50 µm, 35 µm and 25 µm. They found that deviations of frequency and output power are within 1% and 1 dB respectively, with DC parameters also shown to be fairly similar for the different substrate thicknesses. The sensitivity to phase noise when thinning down was found to be significant, which confirms the well-known fact that phase noise sensitivity increases due to leakage. Flexible electronics is changing the way we make and use electronics. Many existing applications, such as wireless communication, wearable electronics, and healthcare monitoring require flexibility to promote more efficient and cost-effective solutions. Development of these flexible electronics is driving progress in the field, which enables futuristic applications such as a network of IoT devices and connected, smart cities. Several initiatives from governments and industry have also contributed to the progress and it is now estimated that the market for flexible electronics will reach $300 billion by 2028, with expected growth from $29 billion in 2017 to over $63 billion in 2023 for printed, flexible and organic electronics alone. The high-performance of CMOS electronics will be critical to this growth in flexible electronics, as a great number of current and future electronics rely on the fast communication and computation they can provide.

Integrating analog and radio-frequency (RF) circuits with digital blocks on a C M O S system-on-a-chip (SoC) has drawn a lot of attention, recently. One major obstacle at this high level of integration is the substrate noise, which results in undesired interaction between these circuits through the common substrate. Analog circuits are the main victims of such interactions; consequently, understanding the behaviour of substrate noise and performance degradations it causes, is indispensable for analog designers. This work addresses three aspects of substrate noise. First, substrate noise is characterized in the time and frequency domains to identify major parameters that control substrate noise generation, propagation, and reception. Effects of many parameters on the amount of noise generation and coupling are also studied. Second, this thesis investigates the noise impact on analog circuits from a circuit-level point of view by introducing a new small-signal model of the M O S device, which accounts for the substrate noise effects. While most works have focused on system-level or signallevel analysis, study of the noise from a circuit-level point of view is more beneficial for analog designers because it gives them more insight on how to improve the substrate noise rejection capability of their designs. Finally, noise reduction techniques are revisited in this work. The use of passive guardrings is reviewed in detail and the effects of many design parameters on the amount of noise attenuation provided by these structures are studied. The behaviour of guard-rings in different substrates are also discussed.