Search Results (29)

Three methods of cellulose-derived polyol synthesis were elaborated. The suitable substrates were (hydroxypropyl)cellulose or cellulose, which were hydroxyalkylated in reactions with glycidol and ethylene carbonate in triethylene glycol or in water. The products were characterized by IR, ¹H NMR, and MALDI ToF spectroscopies. For all polyols, IR spectra showed strong bands at 1060 cm⁻¹ from the ether group formed upon the ring opening of GL and EC. The polyol obtained from (hydroxypropyl)cellulose in the triethylene glycol solvent was accompanied by oligomeric products of glycol hydroxyalkylation and oligomeric glycidol. The polyol obtained by the hydroxyalkylation of cellulose with glycidol and ethylene carbonate in the water contained units of hydroxyalkylated cellulose and products of hydroxyalkylation of water. The physical properties of the obtained polyols, like density, viscosity, and surface tension, were determined. The polyols were then used to obtain rigid polyurethane foams. The foams have apparent density, water uptake, and polymerization shrinkage similar to classic rigid PUFs. The foams showed advantageous thermal resistance in comparison with classic ones. After thermal exposure, their compressive strength improved. The biodegradation of the obtained materials was tested by a respirometric method in standard soil conditions by the measurement of biological oxygen demand and also using the cellulases or the enzymes responsible for cellulose degradation. It has been found that polyols are totally biodegradable within one month of exposure, while the foams obtained thereof are at least 50% biodegraded in the same conditions. The enzymatic biodegradation of the PUFs by the action of microbial cellulase was confirmed. Full article

Authenticated key exchange is desired in scenarios where two participants must exchange sensitive information over an untrusted channel but do not trust each other at the outset of the exchange. As a unique hardware-based random oracle, physical unclonable functions (PUFs) can embed cryptographic hardness and binding properties needed for a secure, interactive authentication system. In this paper, we propose a lightweight protocol, termed PUF-MAKE, to achieve bilateral mutual authentication between two untrusted parties with the help of a trusted server and secure physical devices. At the end of the protocol, both parties are authenticated and possess a shared session key that they can use to encrypt sensitive information over an untrusted channel. The PUF’s underlying entropy hardness characteristics and the key-encryption-key (KEK) primitive act as the root of trust in the protocol’s construction. Other salient properties include a lightweight construction with minimal information stored on each device, a key refresh mechanism to ensure a fresh key is used for every authentication, and robustness against a wide range of attacks. We evaluate the protocol on a set of three FPGAs and a desktop server, with the computational complexity calculated as a function of primitive operations. A composable security model is proposed and analyzed considering a powerful adversary in control of all communications channels. In particular, session key confidentiality is proven through formal verification of the protocol under strong attacker (Dolev-Yao) assumptions, rendering it viable for high-security applications such as digital currency. Full article

Physical Unclonable Functions are security primitives that exploit the variation in integrated circuits’ manufacturing process, and, as a result, each instance processes applied stimuli differently. This feature can be used to provide a unique fingerprint of the electronic device, or as an interesting alternative to classic key storage methods. Due to their nature, they are often considered an element of the Internet of Things nodes. However, their application heavily depends on resource consumption. Lightweight architectures are proposed in the literature but are technology-dependent or still introduce significant hardware overhead. This paper presents a lightweight, Strong PUF based on ring oscillator architecture, which offers small hardware overhead and sufficient security levels for resource-constrained Internet of Things devices. The PUF design utilizes a Linear Feedback Shift Register-based scramble module to generate many challenge–response pairs from a small number of ring oscillators and a control module to manage the response generation process. The proposed PUF can be used as a Weak PUF for key generation or a Strong PUF for device authentication. Full article

Physical Unclonable Functions (PUFs) are significant in building lightweight Internet of Things (IoT) authentication protocols. However, PUFs are susceptible to attacks such as Machine-Learning(ML) modeling and statistical attacks. Researchers have conducted extensive research on the security of PUFs; however, existing PUFs do not always possess good statistical characteristics and few of them can achieve a balance between security and reliability. This article proposes a strong response-feedback PUF based on the Linear Feedback Shift Register (LFSR) and the Arbiter PUF (APUF). This structure not only resists existing ML modeling attacks but also exhibits good Strict Avalanche Criterion (SAC) and Generalized Strict Avalanche Criterion (GSAC). Additionally, we introduce a Two-Level Reliability Improvement (TLRI) method that achieves 95% reliability with less than 35% of the voting times and single-response generation cycles compared to the traditional pure majority voting method. Full article

The family Bignoniaceae includes Handroanthus impetiginosus trees, which are sparsely distributed in the northeast of Brazil. Natural products play a vital role in the discovery of drugs for various diseases. Many plants have been used as sources of medicines because of their chemical diversity and potent bioactivity. Handroanthus impetiginosus has been used traditionally to cure a wide range of illnesses, such as cancer, oxidative stress, and inflammation. This work highlights the cytotoxicity, cell death, and routes of apoptosis in lung cancer cells (A549) and the anti-inflammatory and antioxidant effects of roasted Handroanthus impetiginosus (lapacho/taheebo) in normal cells. The cell viability assay indicated that puffing roasted taheebo is nontoxic to a normal cell line up to 500 µg/mL but significantly toxic to A549 cells. The roasted lapacho/taheebo also increases reactive oxygen species (ROS) generation in A549 lung cancer cells, and cellular apoptosis via a mitochondrial intrinsic pathway was confirmed. The roasted lapacho/taheebo significantly inhibited both colony formation and cell migration ability, highlighting its potential as an anticancer agent. Additionally, this study demonstrates that roasted taheebo enhanced the expression of genes for BAX accumulation and decreased Bcl-2 gene expression through the p53 signaling pathway. Furthermore, research on the anti-inflammatory properties of roasted taheebo revealed a strong NO inhibition as well as the inhibition of inflammatory mediators (TNF-α, iNOS, COX-2, IL-6, and IL-8) through the NF-κB signaling pathway. However, in H₂O₂-induced HaCaT cells, roasted taheebo extract significantly reduced oxidative stress by upregulating the level of expression of antioxidative markers (SOD, CAT, GPx, and GST) at 50 μg/mL. As a result, roasted taheebo justifies investigation in animal and clinical trials as a possible source of antioxidants, anti-inflammatory substances, and anti-cancer compounds. Full article

The rapid advancement of technology has led to the pervasive presence of electronic devices in our lives, enabling convenience and connectivity. Cryptography offers solutions, but vulnerabilities persist due to physical attacks like malware. This led to the emergence of Physical Unclonable Functions (PUFs). PUFs leverage the inherent disorder in physical systems to generate unique responses to challenges. Strong PUFs, susceptible to modeling attacks, can be predicted by malicious parties using machine learning and algebraic techniques. Weak PUFs, with minimal challenges, face similar threats if built upon strong PUFs. Despite some weaknesses, PUFs serve as security components in various protocols. Modeling attacks’ success depends on suitable models and machine learning algorithms. Logistic Regression and Random Forest Classifier are potent in this context. Deep learning techniques, including Convolutional Neural Networks (CNNs) and Artificial Neural Networks (ANNs), exhibit promise, particularly in one-dimensional data scenarios. Experimental results indicate CNN’s superiority, achieving precision, recall, and accuracy exceeding 90%, demonstrating its effectiveness in breaking PUF security. This signifies the potential of deep learning techniques in breaking PUF security. In conclusion, this paper highlights the urgent need for improved security measures in the face of evolving technology. It proposes the utilization of deep learning techniques, particularly CNNs, to strengthen the security of PUFs against modeling attacks. The presented findings underscore the critical importance of reevaluating PUF security protocols in the era of ever-advancing technological threats. Full article

Textile dyes widely used in industrial products are known as a major threat to human health and water ecological security. On the other hand, sol gel represents a principal driver of the adoption of dispersive solid-phase microextractors (d-µ SPME) for pollutants residues in water. Thus, the current study reports a new and highly rapid and highly efficient hybrid sol-gel-based sponge polyurethane foam as a dispersive solid-phase microextractor (d-µ-SPME) platform packed mini-column for complete preconcentration and subsequent spectrophotometric detection of eosin Y textile dye in wastewater. The unique porous structure of the prepared sol-gel immobilized polyurethane foams (sol-gel/PUF) has suggested its use for the complete removal of eosin Y dye (EY) from water. In the mini-column, the number (N) of plates, the height equivalent to the theoretical plates (HETP), the critical capacity (CC), and the breakthrough capacities (BC) of the hybrid sol-gel-treated polyurethane foams towards EY dye were determined via the breakthrough capacity curve at various flow rates. Under the optimum condition using the matrix match strategy, the linear range of 0.01–5 µg L⁻¹, LODs and LOQs in the range of 0.006 µg L⁻¹, and 0.01 µg L⁻¹ for wastewater were achieved. The intra-day and inter-day precisions were evaluated at two different concentration levels (0.05 and 5 μg L⁻¹ of dye) on the same day and five distinct days, respectively. The analytical utility of the absorbents packed in pulses and mini-columns to extract and recover EY dye was attained by 98.94%. The column could efficiently remove different dyes from real industrial effluents, and hence the sol-gel/PUF is a good competitor for commercial applications. The findings of this research work have strong potential in the future to be used in selecting the most suitable lightweight growing medium for a green roof based on stakeholder requirements. Therefore, this study has provided a convenient pathway for the preparation of compressible and reusable sponge materials from renewable biomass for efficient removal of EY from the water environment. Full article

It is easy to cause increases in temperature and the gasification of water in materials, facilitated via supercharging and the generation of instantaneous strong pressure under the collaborative action of a microwave and a vacuum, thus facilitating the internal cell swelling of materials, changes in fibre structures, and the formation of loose and uniform microstructures. In this experiment, mulberries were dehydrated using microwave–vacuum drying technology. The drying characteristics were disclosed by using crispness as the evaluation index and multiple drying parameters (e.g., products’ surface temperature, microwave power, chamber vacuum level and drying height) as the control variables. The optimised Two-term model can predict the dehydration process of mulberries under multiple drying variables, as determined through the experimental data. The optimal drying variables were determined according to the crispness of the dried mulberries. The optimal puffing quality of mulberries could be gained under a product surface temperature = 50 °C, microwave power = 5.45 W/g, a chamber vacuum level = 0.08 MPa and a drying height = 0 cm. The diffusion coefficient of the available water of the mulberries during the microwave–vacuum drying process ranges from 4.98 × 10⁻⁸ to 3.81 × 10⁻⁷, and the activation energy for drying is 183.923 KJ/mol. Full article

Clinical trials of new drugs often face a high failure rate of approximately 45 percent due to safety and toxicity concerns. Repurposing drugs with well-established safety profiles becomes crucial in addressing this challenge. Colon cancer ranks as the third most prevalent cancer and the second leading cause of cancer related mortality worldwide. This study focuses on the RNA-binding protein pumilio1 (PUM1), a member of the PUF family involved in post-transcriptional gene expression regulation. By utilizing molecular docking techniques and FDA-approved drugs, potential inhibitors against PUM1 were identified. Notably, dolasetron and ketoprofen demonstrated promising results, exhibiting strong binding affinity, hydrophobic interactions, and favorable chemical reactivity according to Conceptual-DFT calculations. Both compounds effectively reduced cell viability, with IC50 values of 150 µM and 175 µM, respectively and shows long term inhibitory effects as seen by reduced in number of colonies. Moreover, they exhibited inhibitory effects on colon cancer stem cells, as indicated by reduced colonospheroid size and numbers. Apoptosis is induced by these compounds and has triggered activation of executioner caspase 3/7 in HCT116 cells which is evident through a caspase 3/7 assay and AO/EB staining, while the non-toxic effect of these compounds was evident from viability against non-cancerous cell line and hemolysis assay. Additionally, the treatment group showed a significant decrease in PUM1 and cancer stem cell markers expression compared to the control group. In conclusion, this study highlights the potential of targeting PUM1 as a novel approach to colon cancer treatment. Dolasetron and ketoprofen demonstrate promise as effective anti-cancer and anti-cancer stem cell drugs, inducing apoptosis in colon cancer cells through inhibition of PUM1. Full article

The Space–Air–Ground Integrated Network (SAGIN) expands cyberspace greatly. Dynamic network architecture, complex communication links, limited resources, and diverse environments make SAGIN’s authentication and key distribution much more difficult. Public key cryptography is a better choice for terminals to access SAGIN dynamically, but it is time-consuming. The semiconductor superlattice (SSL) is a strong Physical Unclonable Function (PUF) to be the hardware root of security, and the matched SSL pairs can achieve full entropy key distribution through an insecure public channel. Thus, an access authentication and key distribution scheme is proposed. The inherent security of SSL makes the authentication and key distribution spontaneously achieved without a key management burden and solves the assumption that excellent performance is based on pre-shared symmetric keys. The proposed scheme achieves the intended authentication, confidentiality, integrity, and forward security, which can defend against masquerade attacks, replay attacks, and man-in-the-middle attacks. The formal security analysis substantiates the security goal. The performance evaluation results confirm that the proposed protocols have an obvious advantage over the elliptic curve or bilinear pairings-based protocols. Compared with the protocols based on the pre-distributed symmetric key, our scheme shows unconditional security and dynamic key management with the same level performance. Full article

Physical Unclonable Functions (PUFs) are considered attractive low-cost security anchors in the key generation scheme. The helper data algorithm is usually used to transform the fuzzy responses extracted from PUF into a reproducible key. The generated key can be used to encrypt secret data in traditional security schemes. In contrast, this work shows that the fuzzy responses of both weak and strong PUFs can be used to secretly store the important data (e.g., the distributed keys) directly by an error-tolerant algorithm, Fuzzy Vault, without the traditional encryption algorithm and helper data scheme. The locking and unlocking methods of our proposal are designed to leverage the feature of weak and strong PUFs relatively. For the strong PUFs, our proposal is a new train of thought about how to leverage the advantage of strong PUFs (exponential number of challenge–response pairs) when used in the field. The evaluation was performed on existing weak PUF and strong PUF designs. The unlocking rate and runtime are tested under different parameters and environments. The test results demonstrate that our proposal can reach a 100% unlocking rate by parameter adjustment with less than 1 second of locking time and a few seconds of unlocking time. Finally, the tradeoff between security, reliability, and overhead of the new proposal is discussed. Full article

Machine-to-machine (M2M) communication is one of the critical technologies of the industrial Internet of Things (IoT), which consists of sensors, actuators at the edge, and servers. In order to solve the security and availability problems regarding communication between edge devices with constrained resources and servers in M2M communication, in this study we proposed an authentication and session establishment protocol based on physical unclonable functions (PUFs). The scheme does not require clock synchronization among the devices, and it circumvents the situation where the authentication phase has to use a high computational overhead fuzzy extractor due to PUF noise. The protocol contains two message interactions, which provide strong security and availability while being lightweight. The security modelling is based on CPN Tools, which verifies security attributes and attack resistance in the authentication phase. After considering the design of the fuzzy extractor and scalability, the proposed scheme significantly reduces the computational overhead by more than 93.83% in the authentication phase compared with other schemes using PUFs. Meanwhile, under the guarantee of availability, the communication overhead is maintained at a balanced and reasonable level, at least 19.67% lower than the solution using XOR, hashing, or an elliptic curve. Full article

The recent advancement of the Internet of Things (IoT) in the fields of smart vehicles and integration empowers all cars to join to the internet and transfer sensitive traffic information. To enhance the security for the Internet of Vehicles (IoV) and maintain privacy, this paper proposes an ultralight authentication scheme. Physical unclonable function (PUF), supervised machine learning (SML), and XOR functions are used to authenticate both server and device in a two message flow. The proposed framework can authenticate devices with a low computation time (3 ms) compared to other proposed frameworks while protecting against existing potential threats. Furthermore, the proposed framework needs low overhead (21 bytes) that avoids adding to the IoV network’s workload. Moreover, SML makes weak PUF responses as random numbers to provide the functionality of a strong PUF for the framework. In addition, both formal (Burrows, Abadi, Needham (BAN) logic) and informal analysis are presented to show the resistance against known attacks. Full article

Physical unclonable functions (PUFs) are gaining traction as an attractive alternative to generating and storing device keying material over traditional secure non-volatile memory (NVM) technologies. In this paper, we propose an engineered delay-based PUF called the shift-register, reconvergent-fanout (SiRF) PUF, and present an analysis of the statistical quality of its bitstrings using data collected from a set of FPGAs subjected to extended industrial temperature-voltage environmental conditions. The SiRF PUF utilizes the Xilinx shift register primitive and an engineered network of logic gates that are designed to distribute signal paths over a wide region of the FPGA fabric using a MUXing scheme similar in principle to the shift-rows permutation function within the Advanced Encryption Standard algorithm. The shift register is utilized in a unique fashion to enable individual paths through a Xilinx 5-input LUT to be selected as a source of entropy by the challenge. The engineered logic gate network utilizes reconvergent-fanout as a means of adding entropy, eliminating bias and increasing uncertainty with respect to which paths are actually being timed and used in post-processing to produce the secret key or authentication bitstring. The SiRF PUF is a strong PUF build on top of a network with 10’s of millions of possible paths. Full article

A network of agents constituted of multiple unmanned aerial vehicles (UAVs) is emerging as a promising technology with myriad applications in the military, public, and civil domains. UAVs’ power, memory, and size constraints, ultra-mobile nature, and non-trusted operational environments make them susceptible to various attacks, including physical capturing and cloning attacks. A robust and resilient security protocol should be lightweight and resource-efficient in addition to providing protection against physical and tampering threats. This paper proposes an authentication protocol for a UAV-based multi-agent system robust against various threats and adversaries, including strong resistance against cloning and physical attacks. The proposed protocol is based on a physical unclonable function (PUF), a well-known hardware security primitive that is utilized for low-cost authentication and cryptographic key generation. The analysis of the proposed approach shows that it provides strong protection against various attacks, including tampering and cloning, and exhibits scalability and energy efficiency. Full article