MCRO-PUF: A Novel Modified Crossover RO-PUF with an Ultra-Expanded CRP Space

With the expanding use of the Internet of Things (IoT) devices and the connection of humans and devices to the Internet, the need to provide security in this field is constantly growing. The conventional cryptographic solutions need the IoT device to store secret keys in its non-volatile memory (NVM) leading the system to be vulnerable to physical attacks. In addition, they are not appropriate for IoT applications due to their complex calculations. Thus, physically unclonable functions (PUFs) have been introduced to simultaneously address these issues. PUFs are lightweight and easy-to-access hardware security primitives which employ the unique characteristics of integrated circuits (ICs) to generate secret keys. Among all proposed PUFs, ring oscillator PUF (RO-PUF) has had a more suitable structure for hardware implementation because of its high reliability and easier providing of circuital symmetry. However, RO-PUF has not been so attractive for authentication purposes due to its limited supported challenge-response pairs (CRPs). A few efforts have been made in recent years that could successfully improve the RO-PUF CRP space, such as configurable RO-PUF (CRO-PUF). In this paper, by considerably improving the CRO-PUF structure and adding spare paths, we propose a novel strong RO-PUF structure that exponentially grows the CRP space and dramatically reduces the hardware cost. We implement our design on a simple and low-cost FPGA chip named XC6SLX9-2tqg144, stating that the proposed design can be used in IoT applications. In addition, to improve the CRP space, our design creates a suitable improvement in different security/performance terms of the generated responses, and dramatically outperforms the state-of-the-art. The average reliability, uniqueness, and uniformity of the responses generated are 99.55%, 48.49%, and 50.99%, respectively.     

Multilevel States of Nano‐Electromechanical Switch for a PUF‐Based Security Device

A nano‐electromechanical (NEM) switch using multilevel states based on the high security physical unclonable function (PUF) is proposed and experimentally demonstrated. Using the asymmetric random stiction of a silicon nanowire (SiNW), the conventional binary state is simply expanded to a quaternary‐state encryption key without increasing chip area. The multiple states are determined by the asymmetrically bent direction and stiction of the SiNW. The experimental results show that the fabricated NEM‐PUF with multistates retains unique, random, and robust characteristics, while the key capacity is doubled, even with the same array size footprint.     

无模板剂二次生长法制备可调大孔的沸石泡沫

利用聚氨酯泡沫为模板,经纳米silicalite-1沸石晶种化后,在不含有机模板剂的凝胶体系中进行二次生长,制备了具有丰富可调大孔的ZSM-5沸石材料,该材料保持了聚氨酯泡沫模板的大孔结构.这种沸石构建的大孔材料可以在一定程度上消除扩散限制,有望使沸石在吸附、分离以及催化领域能够得到更有效的利用.     

Attack Resilient True Random Number Generators Using Ferroelectric-Enhanced Stochasticity in 2D Transistor

By harnessing the physically unclonable properties, true random number generators (TRNGs) offer significant promises to alleviate security concerns by generating random bitstreams that are cryptographically secured. However, fundamental challenges remain as conventional hardware often requires complex circuitry design, showing a predictable pattern that is susceptible to machine learning attacks. Here, a low-power self-corrected TRNG is presented by exploiting the stochastic ferroelectric switching and charge trapping in molybdenum disulfide (MoS₂) ferroelectric field-effect transistors (Fe-FET) based on hafnium oxide complex. The proposed TRNG exhibits enhanced stochastic variability with near-ideal entropy of ≈1.0, Hamming distance of ≈50%, independent autocorrelation function, and reliable endurance cycle against temperature variations. Furthermore, its unpredictable feature is systematically examined by machine learning attacks, namely the predictive regression model and the long-short-term-memory (LSTM) approach, where nondeterministic predictions can be concluded. Moreover, the generated cryptographic keys from the circuitry successfully pass the National Institute of Standards and Technology (NIST) 800–20 statistical test suite. The potential of integrating ferroelectric and 2D materials is highlighted for advanced data encryption, offering a novel alternative to generate truly random numbers.     

Strain-sensing fabrics for wearable kinaesthetic-like systems

In recent years, an innovative technology based on polymeric conductors and semiconductors has undergone rapid growth. These materials offer several advantages with respect to metals and inorganic conductors: lightness, large elasticity and resilience, resistance to corrosion, flexibility, impact strength, etc. These properties are suitable for implementing wearable devices. In particular, a sensitive glove able to detect the position and the motion of fingers and a sensorized leotard have been developed. Here, the characterization of the strain-sensing fabric is presented. In the first section, the polymerization process used to realize the strain sensor is described. Then, the thermal and mechanical transduction properties of the strain sensor are investigated and a geometrical parameter to invariantly codify the sensor response during aging is proposed. Finally, a brief outline of ongoing applications is reported.     

Tri-functional metasurface enhanced with a physically unclonable function

In optical anti-counterfeiting, several distinct optically variable devices (OVDs) are often concurrently employed to compensate for the insufficient security level of constituent OVDs. Alternatively, metasurfaces that exhibit multiple optical responses effectively combine multiple OVDs into one, thus significantly enhancing their security and hindering fraudulent replication. This work demonstrates the simultaneous control of three separate optical responses, i.e., phase, amplitude, and luminescence, using anisotropic gap-plasmon metasurfaces. Due to the incorporated geometric anisotropy, the designed structure exhibits distinct responses under x- and y-polarized light, revealing either a color image, or a holographic projection in the far-field. Furthermore, inserting upconversion nanoparticles (UCNPs) into the dielectric gaps of the structures, the designed metasurface is able to generate a third luminescent image upon illumination with the near-infrared light. The stochastic distribution of the UCNPs constitutes a unique “fingerprint”, achieving a physically unclonable function (PUF) layer. Crucially, our triple-mode metasurface requires only readily attainable equipment such as a macro-lens/camera and a laser pointer to read most of the channels, thus paving the way towards highly secure and easy-to-authenticate metasurface-driven OVDs (mOVDs).     

UHM WPE-PUF复合材料结构设计与隔爆实验

采用层状复合工艺,制备了超高分子量聚乙烯(UHMWPE)-聚氨酯泡沫材料(PUF)复合材料;设计了复合材料隔爆实验,运用定制的聚偏氟乙烯(PVDF)压电传感器,直接测量了隔爆实验中材料内部冲击波压力,研究了UHMWPE-PUF复合材料对爆炸冲击波的衰减性能。研究表明,所制备的UHMWPE-PUF复合材料隔爆能力与同厚度的纯聚氨酯材料相比提高了近50%。将UHMWPE材料与PUF材料进行复合,可以充分发挥UHMWPE材料的高强、高模以及PUF材料较高的吸能特点,同时又弥补了PUF材料强度低的缺陷,且材料对爆炸冲击波的衰减性能得到极大提升,在爆炸防护领域有着很好的应用前景。     

Lightweight Authentication Protocol Based on Physical Unclonable Function

In the emerging Industrial Internet of Things (IIoT), authentication problems have become an urgent issue for massive resource-constrained devices because traditional costly security mechanisms are not suitable for them. The security protocol designed for resource-constrained systems should not only be secure but also efficient in terms of usage of energy, storage, and processing. Although recently many lightweight schemes have been proposed, to the best of our knowledge, they are unable to address the problem of privacy preservation with the resistance of Denial of Service (DoS) attacks in a practical way. In this paper, we propose a lightweight authentication protocol based on the Physically Unclonable Function (PUF) to overcome the limitations of existing schemes. The protocol provides an ingenious authentication and synchronization mechanism to solve the contradictions amount forward secrecy, DoS attacks, and resource-constrained. The performance analysis and comparison show that the proposed scheme can better improve the authentication security and efficiency for resource-constrained systems in IIoT.     

Surface acoustic wave gas sensor of the sorption type sensitive to the thermal properties of gases

The basic principles of a new surface acoustic wave (SAW) gas sensor are described. Being essentially a sensor of the sorption type, the proposed device possesses certain features of the thermometric SAW sensors and is not only sensitive to the vapors of volatile substances, but capable of detecting gases by their thermal properties as well. In contrast to the known thermometric SAW sensors, the proposed sensor is characterized by high temperature stability and fast response. A variant of the sensor based on a LiNbO₃ SAW delay line is described and some results of the test for detecting propane-butane mixtures are presented.     

埃洛石自组装涂层在软质聚氨酯泡沫上的制备及其阻燃抑烟性能

使用层层自组装技术在软质聚氨酯泡沫(PUF)表面制备含埃洛石的层层自组装涂层,使用扫描电子显微镜、能谱分析仪和锥形量热仪等手段对涂层进行表征,研究了涂层对PUF的热稳定性、燃烧性能及烟气释放性能的影响。结果表明：埃洛石基涂层由埃洛石、海藻酸钠和聚乙烯亚胺组成,能均匀地附着在PUF表面;涂层能延缓PUF在高温条件下的热解且使残炭量明显增多;三层埃洛石基涂层PU-3的热释放速率峰值、烟气释放速率峰值以及总烟气释放量比纯PUF(PU-0)分别降低了57.3%、58.9%和80.7%。这表明,埃洛石涂层能提高材料的热稳定和火灾安全性。     

Mechanistic modelling of tests of unbound granular materials

Various tests are used to characterise the strength and resilience of granular materials used in the subbase of a pavement system, but there is a limited understanding of how particle properties relate to the bulk material response under various test conditions. Here, we use discrete element method (DEM) simulations with a mechanistically based contact model to explore influences of the material properties of the particle on the results of two such tests: the dynamic cone penetrometer (DCP) and the resilient modulus tests. We find that the measured resilient modulus increases linearly with the particle elastic modulus, whereas the DCP test results are relatively insensitive to particle elastic modulus. The DCP test results are also relatively insensitive to inter-particle friction coefficient but strongly dependent on the particle shape. We discuss strengths and weaknesses of our modelling approach and include suggestions for future improvements.     

新型磷氮型阻燃剂的制备及其阻燃聚氨酯泡沫塑料

以三（2-羟乙基）异氰尿酸酯（THEIC）和苯氧基磷酰二氯（PDCP）为主要原料,合成了一种新型磷氮型阻燃剂（PNFR）,借助FTIR、核磁共振光谱（1H-NMR、31P-NMR）对其结构与组成进行了表征。将PNFR与聚磷酸铵（APP）复配用于制备聚磷酸铵-新型磷氮型阻燃剂阻燃聚氨酯泡沫（APP-PNFR/PUF）复合材料,通过极限氧指数（LOI）、垂直燃烧测试、锥形量热和热失重分析对APP-PNFR/PUF复合材料的阻燃性能和热性能进行了研究。结果表明:成功获得了PNFR;此外,PNFR的TGA表明PNFR在N₂气氛下的初始分解温度为249℃,800℃时的残炭量可达33.7%,其具有较高的热稳定性能。APP-PNFR的加入能有效改善PUF的阻燃性能,且当PNFR的添加量与组合聚醚的质量比为7.5%时,可获得综合性能较好的阻燃PUF材料,其中LOI从19%提高至24%,UL-94垂直燃烧等级达到V-0级,热释放速率峰值从110.6 kW/m2降低到94.5 kW/m2;同时,APP-PNFR/PUF3在N₂气氛下的初始分解温度提高了6℃,最大分解速率降低了16.3%,800℃时的残炭量可达33.5%。PNFR的加入不会削弱PUF的物理力学性能。      

Organisational resilience and relational dynamics in triadic networks: a multiple case analysis

This study aims to analyse resilience and relational dynamics (competitive, cooperative and co-opetitive) within a triadic buyer–supplier–supplier context. Our central goal is to show how a buyer’s supplier–supplier relational behaviour leads to and shapes resilience of this triad. We utilised a multiple-design case approach and selected eight buyers and their suppliers from the textile industry in Turkey. By analysing a triadic context from another industry, we conducted validation analyses. Our findings showed a pattern of relationship between the resilience and the relational dynamics of a triad. Built on theory and insights from the cases, we proposed three propositions. We argued that when co-opetition prevails in a triadic context of relations, the triad resilience level is highest. In competitive relational settings the triad resilience level is lowest, and when the relational dynamics are cooperative, the triad resilience level is moderate. This study is the first to introduce and discuss organisational resilience at triadic level. Furthermore, to our knowledge, our insights from cases are among the first attempts to link three types of supplier–supplier relational dynamics to triad resilience via the use of a multiple-design case approach. Therefore, our contributions are likely to extend the organisational resilience and buyer–supplier–supplier relations research.     

反应性乙烯基硅油/聚脲甲醛自修复微胶囊的制备

以聚脲甲醛为囊壁、乙烯基硅油(DY-V401-310硅油)为囊芯,采用原位聚合法成功合成了具有自修复功能的新型微胶囊-聚脲甲醛包覆乙烯基硅油微胶囊.研究了搅拌速度和表面活性剂对微胶囊物理性能的影响,并通过扫描电子显微镜(SEM)、金相显微镜(MS)、激光粒度分析仪和红外光谱(FTIR)对微胶囊的表面形貌、粒径尺寸与分布及其化学结构等性能进行了研究.结果表明,十二烷基苯磺酸钠(SDBS)和明胶均对微胶囊的形成有积极作用,SDBS所制备的微胶囊粒径更小.当SDBS的加入量为1%(质量分数)时,在搅拌速度为600r/min的作用下,可得到平均粒径为123μm、较为理想的微胶囊.     

Resilience and the temporal dimension – the chimera of timely response

This paper presents a framework for reasoning about ‘timely response’, and control versus the temporal organisation of a controlling system. By three empirical examples, we show how a controlling system can be described in terms of perception points, decision points and action points. Our conclusions are that (1) temporal expectancies shape our ability to exercise control at least as much our ability to understand relations and causality, but temporality is rarely part of approaches to modelling human or system performance, (2) temporal organisation of activities shape our ability to exercise control, (3) by utilising the temporal control framework, we can describe important properties of the temporal organisation of a socio-technical system, and (4) the capacity of modelling is limited to what can be known or imagined. Therefore, models describing resilience or stability should include temporality and be based on frameworks generic enough to be applied to a wide variety of situations.     

Energy Scavenging for Inductively Coupled Passive RFID Systems

Deployment of passive radio-frequency identification (RFID) systems or RFID-enhanced sensor networks requires good understanding of the energy scavenging principles. This paper focuses on the energy scavenging design considerations of inductively coupled passive HF RFID systems. The theoretical estimation of the power by a loop antenna is derived, and the effect of the design parameters on the harvested power is investigated. It is shown that the power delivery performance is largely affected by the tag load at the reader. An adaptive matching circuit at the reader is proposed for achieving optimum power delivery performance when the reader has a variable load. Experimental studies confirm analytical derivations     

Preparation and characterization of conductive carbon nanotube-polyurethane foam composites

Electrical, thermal, and morphological properties of the polyurethane foam (PUF)/multiwall carbon nanotube (MWCNT) composites were investigated with the MWCNT content. Electrical conductivity of the PUF/MWCNT composites increased rapidly from 0 to 0.23 S/cm at 0.1 php MWCNT content, then, the electrical conductivity did not change significantly with the increase of MWCNT content up to 0.5 phr because of the aggregation of the MWCNT when the amount of MWCNT was large (0.5 php). The PUF/MWCNT composite having low MWCNT contents (0.01, 0.05, and 0.1 php) showed lower thermal conductivity than that of the PUF/MWCNT composite having higher content (0.5 php). This is maybe due to that the PUF with the lower MWCNT contents (0.01, 0.05, and 0.1 php) showed smaller cell size than that of the PUF with the higher content of MWCNT (0.5 php). From the results of thermal conductivity and cell size of the PUF/MWCNT composites, it is suggested that reduction in cell size of the composite affects lowering the thermal conductivity of the PUF/MWCNT composites. Also, small amount (0.01, 0.05, and 0.1 php) of MWCNT may contribute to decrease the thermal conductivity of the PUF/MWCNT composites.     

Resilience thinking improves SEA: a discussion paper

Strategic environmental assessment is often referred to as a tool for predicting the consequences of planned development. The assumption of predictability of outcomes is inconsistent with reality which is characterised by uncertainty and complexity. Furthermore, the capacity of our life support systems to absorb disturbance and re-organise without changing into undesirable states appears to be of critical importance. Resilience thinking provides a structured way of looking at complexity, uncertainty and interrelatedness of systems and processes, and above all, provides us with new ways of dealing with planning and more effective use of SEA. Resilience thinking provides inspiration for those who want to extend their thinking about sustainability, but it also challenges some ideas underpinning the impact assessment profession (the future is unpredictable; change is inevitable; increasing stability leads to vulnerability). This paper is the result of a lively and well-visited workshop on resilience thinking and SEA at the 2010 IAIA conference in Geneva. It introduces the basic concepts of resilience thinking, and develops ideas for its integration within SEA practice.     

A fluorescent chemosensor for sodium based on photoinduced electron transfer

A new optical sensor suitable for practical measurement of sodium in serum and whole blood samples is described. The optical sensor is based on a novel PET (photoinduced electron transfer) fluoroionophore immobilized in a hydrophilic polymer layer. The design concept of the fluoroionophore follows the receptor-spacer-fluorophore approach to sensor design using intramolecular PET-based signal transduction. Key to the development of this sensor is the identification of a nitrogen-containing, sodium-binding ionophore, coupled with a fluorophore having the correct spectral and electron-accepting properties. The slope of the sensor is approximately 0.5%/mM in the typical clinically significant range of 120-160 mM. This sensor has been implemented into a disposable cartridge, used for a commercially available critical care analyzer (Roche OPTI CCA) with precision better than +/- 1 mM (1 SD). The sensor displays excellent stability against hydrolysis and oxidation, leading to slope changes <5% after 9 months wet storage at 30 degrees C. On the basis of this design concept, fluoroionophores for other cations such as potassium, calcium and magnesium can be prepared by substitution of the ionophore.