bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Interfacial Interaction Between Various Metal Substrates and Epoxies on Bonding Reliability Under High Temperture
Authors: Zhao Shuaijie , Chen Chuantong , Haga Motoharu , Ueshima Minoru , Suzuki Hirose , Takenaka Hiroto , Suganuma Katsuaki
Published: March 2024

The shift from gel encapsulation to epoxy encapsulation has been driven by the need to reduce the size of power modules. However, the dissimilar bond between the encapsulation epoxy and substrate is seen as a potential weak point. Previous studies have largely focused on the impact of epoxy materials on package reliability. Our prior research has highlighted the crucial role played by interfacial interactions between copper substrates and epoxy. In this study, we investigate the influence of interfacial interactions between three metal substrates (copper, Ag-plated copper, nickel-plated copper) and epoxy on the reliability of epoxy encapsulation under high temperature. Two types of epoxy (bisphenol A and cycloaliphatic) were used to encapsulate metal substrates. Encapsulated packages were subjected to a high-temperature storage test (HST) at 200°C for 1000 hours, and changes in bonding strength were measured. We then analyzed the fracture surface and bonding interface at the nanoscale. Our results indicate that substrate material has a significant impact on the reliability of epoxy encapsulation. Both epoxies exhibited the highest initial bonding strength with copper, followed by Ag-plated copper and nickel-plated copper. After HST, we found that the catalytic effect of metals caused the epoxy in contact with the metal substrate to decompose. The decomposition was most significant in epoxy in contact with Ag, followed by copper, which resulted in a significant drop in bonding strength. In contrast, epoxy in contact with nickel showed little decomposition and only little change in bonding strength. These findings will greatly benefit power module design.
Microstructure Evolution and Online Thermal Resistance of Ag Sintered SiC/DBA Power Module During Power Cycling
Authors: Huo Fupeng , Wang Ye , Chen Chuantong , Zhang Zheng , Yamaguchi Yoshiji , Wakasugi Naoki , Suetake Aiji , Suganuma Katsuaki
Published: March 2024

With the increasing power and miniaturization of power electronics, the power cycling reliability and thermal management of power modules have become increasingly crucial. To address this issue, our Lab. has developed a novel instrument that allows simultaneous power cycling and real-time thermal resistance measurement. Utilizing this specific instrument, we investigated the microstructural evolution of the die attachment layer during power cycling and monitored the real-time thermal resistance of the SiC-TEG (Silicon Carbide-Thermal Engineering Group) heater chip/sintered Ag/DBA (Directed Bonded Aluminum with ceramic core of Si3N4) structure. Additionally, strategies to improve the degradation of the microstructure were proposed. The results indicate that after 10000 power cycles, numerous cracks were observed in the sintered Ag layer. However, the addition of 5 wt. % A1 suppressed the generation of cracks significantly. The addition of A1 particles has little effect on the transient thermal resistance during power cycling.
Development of Printed Circuit Boards with High Thermal Conductivity and Low Thermal Expansion by Applying Cu-Mo Composite Materials
Authors: Ito Yohei , Takanishi Kenjiro , Sakamoto Tatsuya , Fujiwara Keisuke , Arai Hitoshi
Published: March 2024

In recent years, electronic devices are strongly required to be smaller, lighter, and more powerful. As a result, mounted components have become smaller, more powerful, and denser, and the heat generation density on printed circuit boards (PCBs) has increased. Since rising component temperatures can lead to component failure, efficient heat removal from the generated heat has become an urgent issue. Since general PCBs have low thermal conductivity, when high heat dissipation is required, methods to increase the thermal conductivity of PCBs have been employed by increasing the copper (Cu) content in the PCB or by placing an aluminum (Al) alloy in the inner layer. However, while Cu and Al have high thermal conductivity, they also have high coefficients of thermal expansion (CTE) and young’s modulus, and the CTE of a PCB with increased thermal conductivity using these materials is high. If the thermal expansion difference between the PCB and mounted components is large, reliability against heat cycles cannot be obtained. Therefore, we have focused on copper-molybdenum (CuMo) composite materials with high thermal conductivity, high elastic modulus, and low thermal expansion. We have been utilizing Cu-Mo for the development of our PCBs and fabricated multilayered CuMo composite PCBs; therefore, this report will focus on the results regarding thermal characterization of prototype PCBs.
A Jettable and Dispensable Liquid Metal Paste as a Thermal Interface Material
Authors: Lazic Milos
Published: March 2024

Metal thermal interface materials (TIMs) have been used in the electronics industry for over 20 years. The thermal performance of any TIMs is defined by their thermal conductivity, bondline thickness, and interfacial resistance. Generally, metal TIMs have very high thermal conductivity and they can be applied in a thin layer. Most of the metals are hard and stiff, making interfacial resistance the biggest obstacle for metal TIMs to overcome. Over the years, many metal TIMs have been developed and used in applications to improve the performance of the components. Recently, liquid metal TIMs are getting more attention, especially in gaming and high-performance applications. They are excellent in terms of accommodating imperfections of the materials they are connecting, but their physical properties can make application risky. To overcome this challenge, a new metal TIMs material - liquid metal paste (LMP) TIM – has been developed.

This paper will examine this new material’s thermal conductivity, viscosity, jetting, and dispensing performance compared with other existing metal TIMs, such as liquid metal. The application in mass manufacturing will be studied, with a solution to prevent leakage and provide higher thermal cycling performance (-40°C / +125°C) for LMP.
A Thermally Enhanced Film Adhesive for Assembling High Power Density Electronic Devices
Authors: Zhao Yuan , Katze Doug , Pre Ana , Wyatt Derek , Sherwood Josh , Virdi Jaskaran
Published: March 2024

Assembly adhesives play a crucial role in packaging and thermal management design for microelectronics devices. The main function of the adhesives is attaching multiple components together to deliver designed functionalities and ensure integrity and reliability of the device. As requirements for performance and functionality increase, heat generated from these devices increases exponentially. For example, local heat flux can easily exceed 50 W/cm2 for IGBT power modules while it may reach several hundred W/cm2 at active areas for Gallium Nitride (GaN) power amplifiers. However, intrinsic thermal conductivity of polymer-based adhesives is around 0.2 W/mK, which increasingly becomes a thermal bottleneck in high power density electronics devices, especially those used in defense and aerospace systems. Effectively and safely dissipating the high heat and ensuring device reliability have become one of the critical tasks in the development of modern aerospace and defense systems.

This paper presents an adhesive film that uses non-electrically conductive particles with high thermal conductivity as fillers in the adhesive to enhance thermal transport. The adhesive film offers an effective thermal conductivity around 0.7 W/mK, which is more than a 3X improvement over conventional assembly adhesives. In addition, the film adhesive has a long work life at ambient conditions with significantly improved processability and controllability, such as bondline thickness control and uniformity, no voids/air pockets, no or minimum resin bleed, etc. They can also be easily converted into preforms with complicated shapes/geometries with typical tolerances less than 10 mil to facilitate assembly processes and ensure a clean and waste free environment.
Optimized Die Preparation and Handling for High Yield Hybrid Die to Wafer Bonding
Authors: Bex Pieter , Phommahaxay Alain , Kennes Koen , Suhard Samuel , Brems Steven , Beyne Eric
Published: March 2024

Hybrid Cu/dielectric bonding is a well-established technology for Wafer-To-Wafer (W2W) bonding, but it is challenging to apply this technology to Die-To-Wafer (D2W) bonding. Very small particles on the die or wafer can lead to voids/non-bonded regions. Processes to clean and activate wafers for hybrid W2W are quite mature, but it is very challenging to apply these to thinned and singulated dies for D2W bonding. To allow a (partial) re-use of the existing wafer level cleaning, metrology and activation processes and equipment, we propose a new concept where dies are being singulated, cleaned and activated on a glass carrier wafer. After the die preparation steps, the dies are directly picked from the carrier wafer. This approach does not involve additional pick & place steps and avoids the use of conventional dicing tapes. The first direct dielectric D2W bonding experiments using this new approach show a very promising bonding yield, with a high number of completely void-free bonded 50 μm thin dies. Additionally, by eliminating dicing tapes, thinned wafers and singulated dies are always supported by a rigid surface, enabling ultrathin die handling. In this study we also report the handling of dies down 10 μm thickness.
Wafer Level Chip Size Package Integration of an Aero-acoustic MEMS Microphone into a Thin and Flexible Substrate
Authors: Erbacher Kolja , Marques Joao Alves , Mackowiak Piotr
Published: March 2024

This publication describes a novel combination of a chip-scale-package-approach for micro-electromechanical

systems with flush surface chip embedding in thermal Polyurethane. The concept enables the

fabrication of thin and flexible substrates in which sensor chips with fragile membranes are integrated. The

presented sensor array can be used for applications like sound source localization in streams of passenger

airplanes whilst test-flights.
Stereolithographic Process for Embedding of Electronic Components into Multi-material Flexible and Stretchable Polymer Substrate to Reduce Stress During Stretching
Authors: Tiedje Tobias , Bräuer Christoph , Luniak Marco , Nieweglowski Krzysztof , Bock Karlheinz
Published: March 2024

The integration of rigid electronic components into stretchable materials is a complex challenge due to contrary material properties. This paper shows a novel approach for the embedding of electronic components into flexible and stretchable polymer substrates using a stereolithographic process that leads to stress reduction during stretching. The key factor is the multi-material printing with various elastic material properties. The paper shows a miniaturized packaged component (e.g. 0201 LED) in a flexible and stretchable substrate based on three different materials. The first material has rigid properties (stiffness 42.25 N/mm) and surrounds a small area of the LED with about 500 μm peripheral frame. The main purpose of this material is to round up the sharp edges of the LED to the next material. The second material is more elastic (stiffness 0.11 N/mm) and surrounds the first embedded LED. The purpose of the implementation of the second intermediate material is to spread the load between the LED and stretchable substrate caused by stretching. The third material has even higher elastic properties (stiffness 0.05 N/mm) and builds up the main part of the stretchable substrate (size of (4.5x34) mm2). After the fabrication of the multi-material substrate with the embedded LED, horseshoe conductive traces are screen printed with conductive paste. Finally, the embedded LED substrate with the conductive traces is cured at 125 °C. The final stretchable substrate with the embedded LED was able to stretch up to about 25 % for 30 cycles without disturbing the electrical function.
Automotive Grade WLCSP for Radar Applications
Authors: Lakhera Nishant , Carpenter Burt , Lau Teck Beng , Mawer Andrew J.
Published: March 2024

Wafer-Level Chip Scale Packages (WLCSPs) are becoming commonplace in the industry due to their small form factor. Applications include industrial and automotive which demand high reliability performance. Additionally, WLCSPs may be superior in some implementations to other package options for RF performance in the mmWave spectrum, which is desired for automotive radar application. In this study the industry’s first auto grade 1 capable large WLCSP package. (~ 72 mm2 body size, 18x15 BGA array, 0.5 mm pitch) will be presented. It will be demonstrated how extensive design enhancements, predictive simulations, careful package materials and process selection and assembly process optimization studies are required to develop a robust package solution.

Multiple assembly process experiments and corner studies were conducted to demonstrate robustness of WLCSP package solution to meet automotive grade quality and reliability requirements. Both component/unit level and board level reliability was evaluated as per AECQ100 standards. Robustness margins were confirmed through reliability testing performed up to 2-3x reliability requirements.
Development of Wafer Level Package Platform for High Reliability Crossover MCUs
Authors: Sharma Gaurav , Su Meng Yao , Thukral Varun , Beddingfield Craig , Lakhera Nishant
Published: March 2024

Fan in and fan out wafer level packages are primarily used in the industry for applications in handheld consumer electronic products. The key benefits of wafer level package (WLP) are small form factor, reduced cost, improved electrical and thermal performance. WLP investigated in this study are directly surface mounted on PCB and have no intermediate substrate. Direct mount of package on PCB, leads to significant CTE mismatch between the package and board which stresses the package solder joint, leading to cyclic fatigue induced solder joint cracking. To overcome the solder joint cracking, stiffer solder alloys have been evaluated. However, higher stiffness of the solder alloy shifts the cyclic stress induced failure, from the solder joint to the package metal interconnect layers. Moreover, WLP on advanced silicon node have fragile low-k and extremely low-k back end of line dielectric layers that also crack or delaminate in cyclic fatigue.

In this work extensive WLP platform development has been done with following DOE variables; multi-layer package routing, dielectric materials, solder alloys, solder ball pitch and diameter. Developed packages passed and outperformed the following product reliability qualification conditions: high temperature storage life (150°C, 2000 hours), highly accelerated stress test (110°C / 85%RH / Bias, 528 hours), application level temperature cycling ((-40 °C to 125 °C, 600 cycles), board level temperature cycling (-40 °C to 125 °C, 500 cycles) and board level drop test (1500g/0.5ms, 30 drops). Excellent reliability, functional performance, and successful chip package integration was achieved for WLP for crossover MCU products.
Board Level Reliability Testing of RF Packages
Authors: Bora Mumtaz Y.
Published: March 2024

Board level reliability testing is becoming a requirement amongst users for acceptance of components and packages. Standard component level JEDEC tests are not sufficient to qualify a supplier, this must be accompanied with Board level reliability data to ensure assembly and field reliability. The paper presents a summary of board level reliability test performed on RF packages, the assembly process controls and monitoring, mechanical and environmental reliability tests, understanding of failure modes and lessons learned.
Adhesive Solutions for Closed Cavity Packaging
Authors: Schirmer Patrick , Ringelstetter Severin
Published: March 2024

The trend towards autonomous driving demands continuously increasing safety requirements and hence reliable components such as CMOS image sensors or communication devices. To provide such components, manufactures are facing ever greater challenges as the sensor packages need to be airtight-sealed over its whole lifetime. Typical defects that can be observed when using conventional lid attach materials for closed cavity packages in tests at automotive level (e.g., according to AEC Q100) are pop-up effects and delamination. To avoid these defects and to meet the increasing reliability requirements of the semiconductor industry, DELO Industrial Adhesives has developed special adhesives that not only ensure reliable bonding while keeping narrow and high bondlines, but also improve process stability. The required adhesive properties were defined by an FE analysis model. To test suitability of the new developments, dummy image sensor packages were built up, which passed through the testing of the bearing, according to AEC Q 100 standard. Finally, the tightness of the bondline was checked via microscope and other methods. Features such as light/heat B-stage or light fixation help to keep the attached lid in place during heat curing and other subsequent steps like temperature cycling, humidity storage or reflow.
Reliability Assessment of Indium Micro Bumps for 2.5D/3D Electronic Packaging through Cryo-Argon Milling Technique
Authors: Razmyar Soheil , Lay Nicholas , Rahim Kaysar
Published: March 2024

Indium bumps are widely used in electronic packaging for interconnecting microelectronic devices due to their low melting point of 156.6°C, excellent bonding capabilities at room temperature, high thermal conductivity, ductility at extremely low temperatures, and ability to compensate for the mismatched coefficient of thermal expansion (CTE) between different materials. However, cross-sectioning indium bumps can be challenging due to the softness and low melting point of indium. The cutting tools and techniques used must be optimized for the specific sample being analyzed, and specialized preparation techniques such as cryogenic freezing or chemical etching may be required, which can be expensive and time-consuming. Cryo-Focused Ion Beam (FIB) is also a technically demanding process that requires careful optimization of milling parameters, multiple iterations of milling and imaging, specialized equipment, and expertise, which can make it too expensive. It should be noted that the maximum achievable cross-sectional area with cryo-FIB is limited, typically in the range of hundreds of micrometers. Cryo-Argon milling is an effective technique for obtaining high-quality cross-sections of indium bumps arrays and other materials prone to deformation or melting during traditional cross-sectioning. This process involves freezing the sample using liquid nitrogen and bombarding it with a stream of Argon gas ions, which reduces the deformation and melting of the indium. This paper presents challenges related to sample preparation and mechanical polishing for Ar milling technique, and we provide key solutions to these challenges to obtain millimeter-wide and damage-free cross-sections of arrays of indium micro bumps.
Tata Memorial Centre Evidence Based Management of Breast cancer
Authors: Wadasadawala Tabassum , Joshi Shalaka , Rath Sushmita , Popat Palak , Sahay Ayushi , Gulia Seema , Bhargava Prabhat , Krishnamurthy Revathy , Hoysal Dileep , Shah Jessicka , Engineer Mitchelle , Bajpai Jyoti , Kothari Bhavika , Pathak Rima , Jaiswal Dushyant , Desai Sangeeta , Shet Tanuja , Patil Asawari , Pai Trupti , Haria Purvi , Katdare Aparna , Chauhan Sonal , Siddique Shabina , Vanmali Vaibhav , Hawaldar Rohini , Gupta Sudeep , Sarin Rajiv , Badwe Rajendra
Published: March 2024

The incidence of breast cancer is increasing rapidly in urban India due to the changing lifestyle and exposure to risk factors. Diagnosis at an advanced stage and in younger women are the most concerning issues of breast cancer in India. Lack of awareness and social taboos related to cancer diagnosis make women feel hesitant to seek timely medical advice. As almost half of women develop breast cancer at an age younger than 50 years, breast cancer diagnosis poses a huge financial burden on the household and impacts the entire family. Moreover, inaccessibility, unaffordability, and high out-of-pocket expenditure make this situation grimmer. Women find it difficult to get quality cancer care closer to their homes and end up traveling long distances for seeking treatment. Significant differences in the cancer epidemiology compared to the west make the adoption of western breast cancer management guidelines challenging for Indian women. In this article, we intend to provide a comprehensive review of the management of breast cancer from diagnosis to treatment for both early and advanced stages from the perspective of low-middle-income countries. Starting with a brief introduction to epidemiology and guidelines for diagnostic modalities (imaging and pathology), treatment has been discussed for early breast cancer (EBC), locally advanced, and MBC. In-depth information on loco-regional and systemic therapy has been provided focusing on standard treatment protocols as well as scenarios where treatment can be de-escalated or escalated.
Vascularization of choroidal melanomas as a prognostic factor: Comparative analysis between color Doppler and histopathological aspects of tumors
Authors: Costa Marcio Augusto Nogueira , Allemann Norma , Nehemy Andrea , Burnier Miguel Noel Nascente
Published: March 2024

Objectives:

The objective of the study was to correlate color Doppler with the vascularization of choroidal melanoma (CM) observed in histopathological sections and also to analyze the vascular histopathological prognostic factors of these tumors.

Patients, Materials, and Methods:

This was an experimental, cross-sectional, and analytical study carried out at Escola Paulista de Medicina - UNIFESP (São Paulo) and at the Ocular Pathology and Translational Research Laboratory of McGill University (Montreal/Canada). Twenty-five enucleated eyes of patients with CM were studied, 10 patients studied at UNIFESP and 15 patients studied at McGill University. The first 10 patients (Brazil), before enucleation, were submitted to color Doppler, all performed at UNIFESP. The resistance index (RI) and maximum systolic velocity of each tumor were calculated. The inclusion criteria of this study were as follows: CMs >8 mm in thickness, enucleation as primary treatment, histopathological blocks sufficient for hematoxylin–eosin staining, periodic acid–Schiff, and CD34 immunohistochemistry. Exclusion criteria included tumors smaller than 8 mm and/or previous treatments such as laser or brachytherapy. Regarding the histopathology of each CM, cell-type classification, vessel diameter measurements, count of the number of mitoses, and vascular clefts were carried out. The latter are considered vessels because they are lined by endothelium (CD34 positive) and surrounded by melanoma cells.

Results:

There was a statistical correlation between RI and cell type (P < 0.05). Tumors with a better prognosis (spindle cell) showed higher RI compared to epithelioid tumors, with a worse prognosis. The number of mitoses and vascular clefts correlated with the cell type, with a statistically significant difference (P < 0.001). Tumors of worse prognosis (epithelioid) showed an increase in the number of mitoses and in the number of vascular clefts. There was no difference between vessel diameter and cell type.

Conclusions:

The number of vascular clefts has a positive prognostic correlation with the malignancy of CM. Doppler RI showed a positive prognostic correlation with CM malignancy. For the first time, the usefulness of vascular clefts as prognostic factors was proven, and a new classification of the vascular network in CMs was proposed.
Analysis on Smart Healthcare Monitoring Based on Compound Dimension
Authors: Vennilapriya B , Bennila Thangammal C
Published: March 2024

INTRODUCTION: Life expectancy has steadily increased in the majority of countries over the last few decades as a result of vast improvements in medical care, public health initiatives, and individual, community hygiene practices as well. OBJECTIVES: An effective and inexpensive alternative to institutional care was remote health surveillance, which relies on non-invasive and wearable sensors, actuators, and modern statement and information technology to allow the elderly to remain in their familiar homes. METHODS: With the use of open-source software, widely accessible minimal chipsets, and remote data warehouses for storing, this study details the design and construction of e-health apparel for health monitoring. RESULTS: By utilizing these devices, medical professionals will be able to track vital signs in real-time, evaluate patients' status, and provide feedback even when they are physically located in a different facility. The next step included creating a wearable system and the garment platform it would be used on. CONCLUSION: More features were implemented in the form of a smartphone application. This research has potential application in broadening the scope of wearable healthcare systems by investigating the role of apparel in this area.
Detection of Female Anopheles Mosquito-Infected Cells: Exploring CNN, ReLU, and Sigmoid Activation Methods
Authors: Leena Jenifer A L , Indumathi B K , Mahalakshmi C P
Published: March 2024

INTRODUCTION: Deep learning uses multi-layer neural networks where the algorithm decides for itself whether aspects are essential for analysis based on the raw input. In general, deep learning networks get better as more data is used to train them. For a variety of applications, convolutional neural networks are frequently used to analyse, categorize, and detect images. OBJECTIVES: The proposed system technique is used for automated analysis of malaria-detecting frameworks. A female Anopheles mosquito bite is the primary method of transmission of the blood disease malaria. It is still common to manually count and identify parasitized cells during microscopic examination of either thick or thin layers of haemoglobin, which takes time for disease prognosis. METHODS: The current research uses a neural network based on convolution to catalogue images of cells with and without malaria infection. This method improves the precision of classification for the datasets under study. The ReLu activation function used by this model enables it to learn more quickly and perform more effectively. RESULTS: The prediction of infected and healthy cells was done accurately by the proposed model, which uses only 3 layers of convolution, and this was the idea behind the implementation. The model achieved an improved accuracy of 99.77% across 12 iterations (epochs). CONCLUSION: The proposed model is straightforward and successful in differentiating between malaria-infected and uninfected cells.
‘Jail’ in Diné bizaad
Authors: Alonso de la Fuente José Andrés
Published: March 2024

It is argued that certain words for jail in Diné bizaad (Navajo)„ e.g. ’awáalya and wáalya, come from Spanish. Although it has been long suspected that this word is a loanword, all the suggestions so far presented in the literature remain unconvincing on phonological grounds.
An Elementary Construction of Modified Hamiltonians and Modified Measures of 2D Kahan Maps
Authors: Gubbiotti Giorgio , McLaren David , Quispel G. R. W.
Published: March 2024

We show how to construct in an elementary way the invariant of the KHK
discretisation of a cubic Hamiltonian system in two dimensions. That is, we
show that this invariant is expressible as the product of the ratios of affine
polynomials defining the prolongation of the three parallel sides of a hexagon.
On the vertices of such a hexagon lie the indeterminacy points of the KHK map.
This result is obtained analysing the structure of the singular fibres of the
known invariant. We apply this construction to several examples, and we prove
that a similar result holds true for a case outside the hypotheses of the main
theorem, leading us to conjecture that further extensions are possible.
Small Stretch Problem of the DCT Scheme and How to Fix It
Authors: Chen Yuchao , Guo Tingting , Hu Lei , Shang Lina , Mao Shuping , Wang Peng
Published: March 2024

DCT is a beyond-birthday-bound (BBB) deterministic authenticated encryption (DAE) mode proposed by Forler et al. in ACISP 2016, ensuring integrity by redundancy. The instantiation of DCT employs the BRW polynomial, which is more efficient than the usual polynomial in GCM by reducing half of the multiplication operations. However, we show that DCT suffers from a small stretch problem similar to GCM. When the stretch length τ is small, choosing a special m-block message, we can reduce the number of queries required by a successful forgery to O(2τ/m). We emphasize that this attack efficiently balances space and time complexity but does not contradict the security bounds of DCT. Finally, we propose an improved scheme named Robust DCT (RDCT) with a minor change to DCT, which improves the security when τ is small and makes it resist the above attack.
Improved Meet-in-the-Middle Nostradamus Attacks on AES-like Hashing
Authors: Dong Xiaoyang , Guo Jian , Li Shun , Pham Phuong , Zhang Tianyu
Published: March 2024

The Nostradamus attack was originally proposed as a security vulnerability for a hash function by Kelsey and Kohno at EUROCRYPT 2006. It requires the attacker to commit to a hash value y of an iterated hash function H. Subsequently, upon being provided with a message prefix P, the adversary’s task is to identify a suffix S such that H(P∥S) equals y. Kelsey and Kohno demonstrated a herding attack requiring O(√n · 22n/3) evaluations of the compression function of H, where n represents the output and state size of the hash, placing this attack between preimage attacks and collision searches in terms of complexity. At ASIACRYPT 2022, Benedikt et al. transform Kelsey and Kohno’s attack into a quantum variant, decreasing the time complexity from O(√n · 22n/3) to O( 3√n · 23n/7). At ToSC 2023, Zhang et al. proposed the first dedicated Nostradamus attack on AES-like hashing in both classical and quantum settings. In this paper, we have made revisions to the multi-target technique incorporated into the meet-in-the-middle automatic search framework. This modification leads to a decrease in time complexity during the online linking phase, effectively reducing the overall attack time complexity in both classical and quantum scenarios. Specifically, we can achieve more rounds in the classical setting and reduce the time complexity for the same round in the quantum setting.
Finding Impossible Differentials in ARX Ciphers under Weak Keys
Authors: Ling Qing , Cui Tingting , Hu Hongtao , Gong Sijia , He Zijun , Huang Jiali , Xiao Jia
Published: March 2024

Impossible differential cryptanalysis is very important in the field of symmetric ciphers. Currently, there are many automatic search approaches to find impossible differentials. However, these methods have two underlying assumptions: Markov cipher assumption and key independence assumption. Actually, these two assumptions are not true in ARX ciphers, especially lightweight ones. In this paper, we study the impossible differentials in ARX cipher under weak keys for the first time. Firstly, we propose several accurate difference propagation properties on consecutive two and three modular additions. Then, these properties are applied to four typical local constructions composed of two consecutive modular additions, two modular additions with a rotation operation, xoring secret key or constant in the middle, to find impossible differentials under weak keys or special constants. What’s more, we propose a more accurate difference propagation property on three consecutive modular additions. It can be used to find impossible differentials on more complex local constructions under weak keys or special constants. In practical ciphers, these impossible differentials on local constructions can be used to find contradictions. Lastly, combining our new findings with traditional automatic search methods for impossible differentials, we propose a framework to find impossible differentials in ARX ciphers under weak keys. As applications, we apply the framework to SPECK-32/64, LEA and CHAM-64/128. As a result, we find two 8-round impossible differentials for SPECK-32/64 under 260 weak keys, and one 11-round impossible differential for LEA under 2k−1 weak keys, where k is the key size. These impossible differentials can start from any round. Furthermore, we find two 22-round impossible differentials for CHAM-64/128 under 2127 weak keys starting from certain rounds. As far as we know, all these impossible differentials are longer than previous ones.
Building PRFs from TPRPs: Beyond the Block and the Tweak Length Bounds
Authors: Choi Wonseok , Lee Jooyoung , Lee Yeongmin
Published: March 2024

A secure n-bit tweakable block cipher (TBC) using t-bit tweaks can be modeled as a tweakable uniform random permutation, where each tweak defines an independent random n-bit permutation. When an input to this tweakable permutation is fixed, it can be viewed as a perfectly secure t-bit random function. On the other hand, when a tweak is fixed, it can be viewed as a perfectly secure n-bit random permutation, and it is well known that the sum of two random permutations is pseudorandom up to 2n queries.A natural question is whether one can construct a pseudorandom function (PRF) beyond the block and the tweak length bounds using a small number of calls to the underlying tweakable permutations. A straightforward way of constructing a PRF from tweakable permutations is to xor the outputs from two tweakable permutations with c bits of the input to each permutation fixed. Using the multi-user security of the sum of two permutations, one can prove that the (t + n − c)-to-n bit PRF is secure up to 2n+c queries.In this paper, we propose a family of PRF constructions based on tweakable permutations, dubbed XoTPc, achieving stronger security than the straightforward construction. XoTPc is parameterized by c, giving a (t + n − c)-to-n bit PRF. When t < 3n and c = t/3 , XoTPt/3 becomes an (n + 2t/3 )-to-n bit pseudorandom function, which is secure up to 2n+2t/3 queries. It provides security beyond the block and the tweak length bounds, making two calls to the underlying tweakable permutations. In order to prove the security of XoTPc, we extend Mirror theory to q ≫ 2n, where q is the number of equations. From a practical point of view, our construction can be used to construct TBC-based MAC finalization functions and CTR-type encryption modes with stronger provable security compared to existing schemes.
Equivalence of Generalised Feistel Networks
Authors: Derbez Patrick , Euler Marie
Published: March 2024

This paper focuses on equivalences between Generalised Feistel Networks (GFN) of type-II. We introduce a new definition of equivalence which captures the concept that two GFNs are identical up to re-labelling of the inputs/outputs, and give a procedure to test this equivalence relation. Such two GFNs are therefore cryptographically equivalent for several classes of attacks. It induces a reduction o the space of possible GFNs: the set of the (k!)2 possible even-odd GFNs with 2k branches can be partitioned into k! different classes.This result can be very useful when looking for an optimal GFN regarding specific computationally intensive properties, such as the minimal number of active S-boxes in a differential trail. We also show that in several previous papers, many GFN candidates are redundant as they belong to only a few classes. Because of this reduction of candidates, we are also able to suggest better permutations than the one of WARP: they reach 64 active S-boxes in one round less and still have the same diffusion round that WARP. Finally, we also point out a new family of permutations with good diffusion properties.
Design of a Linear Layer Optimised for Bitsliced 32-bit Implementation
Authors: Leurent Gaëtan , Pernot Clara
Published: March 2024

The linear layer of block ciphers plays an important role in their security In particular, ciphers designed following the wide-trail strategy use the branch number of the linear layer to derive bounds on the probability of linear and differential trails. At FSE 2014, the LS-design construction was introduced as a simple and regular structure to design bitsliced block ciphers. It considers the internal state as a bit matrix, and applies alternatively an identical S-Box on all the columns, and an identical L-Box on all the lines. Security bounds are derived from the branch number of the L-Box.In this paper, we focus on bitsliced linear layers inspired by the LS-design construction and the Spook AEAD algorithm. We study the construction of bitsliced linear transformations with efficient implementations using XORs and rotations (optimized for bitsliced ciphers implemented on 32-bit processors), and a high branch number. In order to increase the density of the activity patterns, the linear layer is designed on the whole state, rather than using multiple parallel copies of an L-Box. Our main result is a linear layer for 128-bit ciphers with branch number 21, improving upon the best 32-bit transformation with branch number 12, and the one of Spook with branch number 16.
Tightening Leakage Resilience of the Suffix Keyed Sponge
Authors: Berendsen Henk , Mennink Bart
Published: March 2024

Lightweight cryptographic constructions are often optimized on multiple aspects that put the security bounds to the limit. In this respect, it is important to obtain security bounds that are tight and give an accurate and exact indication of the generic security. However, whereas for black-box security bounds it has become common practice to argue tightness of security bounds, for leakage resilience security bounds this is not the case. This is unfortunate, as for leakage resilience results, tightness is even more important as there is already a lossiness incurred in capturing the actual leakage by a theoretical model in the first place.In this work, we consider the SuKS (Suffix Keyed Sponge) PRF construction and investigate tightness of the leakage resilience bound of Dobraunig and Mennink (ToSC 2019). We observe that, although their black-box security result is tight, their leakage resilience bound is not tight in their bounded leakage term λ. We observe that this is caused by the fact that parts of the security bound contain a term covering multicollisions and a term covering leakage, but an adversary is unable to combine both. We next consider improved security of the SuKS for two types of leakage: fixed position leakage, where the adversary directly learns the value of λ bits of a secret state, and Hamming weight leakage, where the Hamming weight of a fixed part of the state is leaked. For fixed position leakage, a very generous form of bounded leakage, we improve the original bound by making wise use of the multicollision limit function of Daemen et al. (ASIACRYPT 2017). For the more realistic setting of Hamming weight leakage, we structurally revisit the multicollision limit function analysis by including Hamming weight in the computation, a problem that is difficult on its own due to the non-uniform character of this type of leakage. In both cases, we improve and tighten the leakage resilience bound of Dobraunig and Mennink. The improved bound for the SuKS has immediate consequences for the leakage resilience of the NIST lightweight cryptography competition finalist ISAP v2, an authenticated encryption scheme that uses the SuKS internally.
XDRBG: A Proposed Deterministic Random Bit Generator Based on Any XOF
Authors: Kelsey John , Lucks Stefan , Müller Stephan
Published: March 2024

A deterministic random bit generator (DRBG) generates pseudorandom bits from an unpredictable seed, i.e., a seed drawn from any random source with sufficient entropy. The current paper formalizes a security notion for a DRBG, in which an attacker may make any legal sequence of requests to the DRBG and sometimes compromise the DRBG state, but should still not be able to distingush DRBG outputs from ideal random bits. The paper proposes XDRBG, a new DRBG based on any eXtendable Output Function (XOF) and proves the security of the XDRBG in the ideal-XOF model. The proven bounds are tight, as demonstrated by matching attacks. The paper also discusses the security of XDRBG against quantum attackers. Finally, the paper proposes concrete instantiations of XDRBG, employing either the SHAKE128 or the SHAKE256 XDRBG. Alternative instantiations suitable for lightweight applications can be based on ASCON.
Proporcionalidad de los subsidios federales y la matrícula de las Universidades Públicas Estatales en México
Authors: Gómez Cárdenas Juan Francisco , Gómez Álvarez Ricardo , Garza Elizondo Adriana , Contreras Rodríguez Verónica Melisa
Published: March 2024

Las Universidades Públicas en México (UPE´s), son instituciones que atienden el nivel superior cuya su función es desarrollar la academia mediante la docencia, investigación, extensión y difusión de la cultura; cada año firman un convenio con la Secretaría de Educación Pública (SEP) y su respectivo gobierno estatal para el cumplimiento de las funciones sustantivas. La presente investigación tiene como objetivo analizar si las UPE´s reciben los subsidios de manera proporcional a la matrícula atendida, y así, estar en igualdad de condiciones para el cumplimiento de sus objetivos. Para ello, se utilizó un estudio no experimental de tipo cuantitativo y descriptivo mediante datos agrupados, considerando como muestra el 100% de la población; el análisis contempla los años 2019, 2020, 2021 y 2022 referentes al subsidio federal recibido y la matrícula que atendieron en los periodos señalados, teniendo como principal resultado que el promedio de subsidio federal entregado por estudiante es de 58,000 pesos a 68,000 pesos y una desviación de 16,000 pesos; se determina que no existen criterios o reglas claras para la designación, demostrando que los incrementos son sujetos a factores políticos; siendo el indicador de matrícula un excelente referente para la asignación equitativa del subsidio federal.
Design of Rotary Motor Wiring Diagram for Tugboat Ship Maneuvering System Using Cam Switch ControlDesign of Rotary Motor Wiring Diagram for Tugboat Ship Maneuvering System Using Cam Switch Control
Authors:   Department of Industrial and Technology, Vocational School, Diponegoro University,Jl. Gubernur Mochtar, KampusUndipTembalang, Semarang, Indonesia 50275, Sugeng Sunarso , Khristyson Samuel Febriary ,   Department of Industrial and Technology, Vocational School, Diponegoro University,Jl. Gubernur Mochtar, KampusUndipTembalang, Semarang, Indonesia 50275, Panjalu Agas Arsy Taruma ,   Department of Industrial and Technology, Vocational School, Diponegoro University,Jl. Gubernur Mochtar, KampusUndipTembalang, Semarang, Indonesia 50275
Published: March 2024

The maneuverability of tugboats is very necessary for narrow turning areas, so many tugboat maneuvering systems use motors which are currently applied with cam switches. It is important to plan a wiring system to anticipate disruptions to distribution electricity. Therefore, the electricity supply for the equipment can be met and run as expected. The aim of this research is to obtain rotary motor wiring diagram system for tugboat ship maneuvering system using cam switch control. The R&D (Research and Development) method combined with experiments was carried out to obtain an ideal rotary motor wiring diagram system based on the dimensions of the tugboat's engine room. In forward rotation for this motor is a decrease before stabilization occurs, the voltage is 18% meanwhile, reverse rotation experienced a decrease of 32%. This difference with motor if workload which is charged which also experiences variations, for forward rotation the increase is 48%, also for reverse rotation it is 43%.
Ijtimoiy huquqlar tizimida shaxsning sog‘liqqa bo‘lgan huquqining tutgan o‘rni
Authors: Safarova Xulkar
Published: March 2024

Maqolada shaxsning sog‘liqqa bo‘lgan huquqi ijtimoiy huquqlari tizimida tutgan o‘rni universal xalqaro huquqiy hujjatlar va milliy qonun hujjatlari asosida tahlil etilgan. Shaxsning sog‘liqqa bo‘lgan huquqini ta’minlash borasidagi mummolar tahlili asosida xulosa va tavsiyalar ilgari surilgan.
The arbitration agreements and the competence of international commercial arbitration
Authors: Кулжанов Асаматдин
Published: March 2024

The text provides a comprehensive analysis of the role and evolution of international commercial arbitration as a method of alternative dispute resolution. It emphasizes the growing preference for arbitration in international commerce due to its speed, confidentiality, and perceived fairness. The text also highlights the efforts made by the Republic of Uzbekistan to develop its arbitration infrastructure, including its adherence to international conventions and the establishment of the Tashkent International Arbitration Center. The article further delves into the legal intricacies of arbitration agreements, discussing their validity, enforceability, and the formal requirements they must meet. It concludes by noting the ongoing changes in international standards and laws governing arbitration, suggesting that these are in response to the changing needs of the global market
Transitioning to a Hydrogen Future: Analyzing Demand and Supply Dynamics in New Zealand's Transportation Sector
Authors: Sheng Mingyue Selena , Wen Le , Tan Beryl , Poletti Stephen
Published: March 2024

This study conducts a comprehensive literature review, analysing academic articles, government documents, and reports from international organisations to discern trends in hydrogen fuel deployment for heavy transportation in New Zealand. It specifically assesses the current state-of-the-art technology, economic policies, and the impact of hydrogen fuel and fuel-cell vehicles on decarbonisation efforts and economic growth, acknowledging the influence of consumer preferences, diesel prices, and technological advancements on market demand. While recognising the cost-competitiveness challenges these vehicles face, the research highlights the necessity of significant investments in infrastructure development. Methodologically, the study integrates economies of scale and technological learning rates to evaluate hydrogen fuel investment returns. Furthermore, this paper employs the Castalia-MBIE model for scenario analysis, revealing two key insights. First, it underscores the criticality of maintaining a favourable equilibrium between domestic and international production costs alongside hydrogen fuel consumption to bolster New Zealand's competitiveness on the global stage. Second, it highlights the pronounced vulnerability of fuel-cell electric vehicles to supply-side influences as compared to demand-related variables. These insights contribute scientifically to understanding the economic dynamics of hydrogen fuel adoption and its implications for New Zealand's transport sector.
 
Received: 18 July 2023 | Revised: 30 January 2024 | Accepted: 26 February 2024
 
Conflicts of Interest
 The authors declare that they have no conflicts of interest to this work.
 
Data Availability Statement
The data that support the findings of this study are openly available in the New Zealand Wind Energy Association at https://www.windenergy.org.nz/generation#:∼:text=On%20an%20annual%20basis%2C%20New,the%20highest%20in%20the%20world.  
 
Author Contribution Statement
Mingyue Selena Sheng: Conceptualization, Formal analysis, Investigation, Data curation, Writing - review & editing, Supervision, Funding acquisition. Le Wen: Conceptualization, Methodology, Formal analysis, Investigation, Resources, Writing - review & editing, Supervision, Project administration, Funding acquisition. Beryl Tan: Methodology, Software, Validation, Formal analysis, Investigation, Writing - original draft, Visualization. Stephen Poletti: Conceptualization, Writing - review & editing.