21 research outputs found
Finding Three-Subset Division Property for Ciphers with Complex Linear Layers (Full Version)
Conventional bit-based division property (CBDP) and bit-
based division property using three subsets (BDPT) introduced by Todo
et al. at FSE 2016 are the most effective techniques for finding integral
characteristics of symmetric ciphers. At ASIACRYPT 2019, Wang et al.
proposed the idea of modeling the propagation of BDPT, and recently
Liu et al. described a model set method that characterized the BDPT
propagation. However, the linear layers of the block ciphers which are analyzed using the above two methods of BDPT propagation are restricted to simple bit permutation. Thus the feasibility of the MILP method of BDPT propagation to analyze ciphers with complex linear layers is not settled. In this paper, we focus on constructing an automatic search algorithm that can accurately characterize BDPT propagation for ciphers with complex linear layers. We first introduce BDPT propagation rule for the binary diffusion layer and model that propagation in MILP efficiently. The solutions to these inequalities are exact BDPT trails of the binary diffusion layer. Next, we propose a new algorithm that models Key-Xor operation in BDPT based on MILP technique. Based on these ideas, we construct an automatic search algorithm that accurately characterizes the BDPT propagation and we prove the correctness of our search algorithm. We demonstrate our model for the block ciphers with non-binary diffusion layers by decomposing the non-binary linear layer trivially by the COPY and XOR operations. Therefore, we apply our method to search integral distinguishers based on BDPT of SIMON, SIMON(102), PRINCE, MANTIS, PRIDE, and KLEIN block ciphers. For PRINCE and MANTIS, we find (2 + 2) and (3 + 3) round integral distinguishers respectively which are longest to date. We also improve the previous best integral distinguishers of PRIDE and KLEIN. For SIMON, SIMON(102), the integral distinguishers found by our method are consistent with the existing longest distinguishers
IN VITRO MEROPENEM SUSCEPTIBILITY INDUCED BY PH ALTERATION IN METALLO-BETA-LACTAMASE POSITIVE PSEUDOMONAS AERUGINOSA
ABSTRACTObjective: The increasing emergence of metallo-beta-lactamase (MβL) producing Gram-negative bacteria such as Pseudomonas aeruginosa posea serious public health concern including in the treatment of urinary tract infection (UTI). This study was aimed to explore the combined effect ofin vitro pH alteration and antibiotic on the bacterial growth as a potential therapeutic approach against the drug resistant P. aeruginosa.Methods: Ten MβL producing P. aeruginosa isolates from the patients suffering from UTI were included. Bacteria were inoculated with or withoutmeropenem in media with varied pH range from 5 to 10. The variation of bacterial growth was determined by measuring the changes of opticaldensity at 620 nm and colony forming unit counts/ml.Result: The growth of bacteria was reduced both at very high and lower pH ranges. However, the growth was further reduced significantly with theaddition of meropenem at these extreme pH conditions.Conclusion: Alteration of pH especially at lower range of the medium might has changed the efficacy of MβL and thus helped the antibiotic meropenemto act on the bacteria, which was resistant toward the same at neutral pH. Combined effect of antibiotic and pH modulation of biological fluid like urineshould be explored for an effective alternative therapeutic approach against the drug-resistant bacteria.Keywords: Metallo-beta-lactamase, urinary tract infection, Pseudomonas aeruginosa, pH
Unleashing the Power of Differential Fault Attacks on QARMAv2
QARMAv2 represents a family of lightweight block ciphers introduced in
ToSC 2023. This new iteration, QARMAv2, is an evolution of the original QARMA
design, specifically constructed to accommodate more extended tweak values while
simultaneously enhancing security measures. This family of ciphers is available in
two distinct versions, referred to as QARMAv2--, where ‘’ signifies the block
length, with options for both 64-bit and 128-bit blocks, and ‘’ signifies the key
length. In this paper, for the first time, we present differential fault analysis (DFA)
of all the QARMAv2 variants- QARMAv2-64, and QARMAv2-128 by introducing
an approach to utilize the fault propagation patterns at the nibble level, with the
goal of identifying relevant faulty ciphertexts and vulnerable fault positions. This
technique highlights a substantial security risk for the practical implementation of
QARMAv2. By strategically introducing six random nibble faults into the input of
the -th and -th backward rounds within the -round QARMAv2-64,
our attack achieves a significant reduction in the secret key space, diminishing it
from the expansive to a significantly more smaller set of size . Additionally,
when targeting QARMAv2-128-128, it demands the introduction of six random nibble
faults to effectively reduce the secret key space from to a remarkably reduced
. To conclude, we also explore the potential extension of our methods to conduct
DFA on various other iterations and adaptations of the QARMAv2 cryptographic
scheme. To the best of our knowledge, this marks the first instance of a differential
fault attack targeting the QARMAv2 tweakable block cipher family, signifying an
important direction in cryptographic analysis
A potent betulinic acid analogue ascertains an antagonistic mechanism between autophagy and proteasomal degradation pathway in HT-29 cells
Betulinic acid (BA), a member of pentacyclic triterpenes has shown important biological activities like
anti-bacterial, anti-malarial, anti-inflammatory and most interestingly anticancer property. To overcome its poor
aqueous solubility and low bioavailability, structural modifications of its functional groups are made to generate
novel lead(s) having better efficacy and less toxicity than the parent compound. BA analogue, 2c was found most
potent inhibitor of colon cancer cell line, HT-29 cells with IC50 value 14.9 μM which is significantly lower than
standard drug 5-fluorouracil as well as parent compound, Betulinic acid. We have studied another mode of PCD,
autophagy which is one of the important constituent of cellular catabolic system as well as we also studied
proteasomal degradation pathway to investigate whole catabolic pathway after exploration of 2c on HT-29 cells.
Mechanism of autophagic cell death was studied using fluorescent dye like acridine orange (AO) and
monodansylcadaverin (MDC) staining by using fluorescence microscopy. Various autophagic protein expression
levels were determined by Western Blotting, qRT-PCR and Immunostaining. Confocal Laser Scanning Microscopy
(CLSM) was used to study the colocalization of various autophagic proteins. These were accompanied by formation
of autophagic vacuoles as revealed by FACS and transmission electron microscopy (TEM). Proteasomal degradation
pathway was studied by proteasome-Glo™ assay systems using luminometer.The formation of autophagic vacuoles in HT-29 cells after 2c treatment was determined by fluorescence
staining – confirming the occurrence of autophagy. In addition, 2c was found to alter expression levels of different autophagic proteins like Beclin-1, Atg 5, Atg 7, Atg 5-Atg 12, LC3B and autophagic adapter protein, p62. Furthermore we found the formation of autophagolysosome by colocalization of LAMP-1 with LC3B, LC3B with Lysosome, p62 with lysosome. Finally, as proteasomal degradation pathway downregulated after 2c treatment colocalization of ubiquitin
with lysosome and LC3B with p62 was studied to confirm that protein degradation in autophagy induced HT-29 cells
follows autolysosomal pathway. In summary, betulinic acid analogue, 2c was able to induce autophagy in HT-29 cells and as proteasomal degradation pathway downregulated after 2c treatment so protein degradation in autophagy induced HT-29 cell
Granulated deep learning and Z-numbers in motion detection and object recognition
The article deals with the problems of motion detection, object recognition, and scene description using deep learning in the framework of granular computing and Z-numbers. Since deep learning is computationally intensive, whereas granular computing, on the other hand, leads to computation gain, a judicious integration of their merits is made so as to make the learning mechanism computationally efficient. Further, it is shown how the concept of z-numbers can be used to quantify the abstraction of semantic information in interpreting a scene, where subjectivity is of major concern, through recognition of its constituting objects. The system, thus developed, involves recognition of both static objects in the background and moving objects in foreground separately. Rough set theoretic granular computing is adopted where rough lower and upper approximations are used in defining object and background models. During deep learning, instead of scanning the entire image pixel by pixel in the convolution layer, we scan only the representative pixel of each granule. This results in a significant gain in computation time. Arbitrary-shaped and sized granules, as expected, perform better than regular-shaped rectangular granules or fixed-sized granules. The method of tracking is able to deal efficiently with various challenging cases, e.g., tracking partially overlapped objects and suddenly appeared objects. Overall, the granulated system shows a balanced trade-off between speed and accuracy as compared to pixel level learning in tracking and recognition. The concept of using Z-numbers, in providing a granulated linguistic description of a scene, is unique. This gives a more natural interpretation of object recognition in terms of certainty toward scene understanding
In-Situ Forming Polymeric Drug Delivery Systems for Ophthalmic Use: An Overview
Delivery of drug into the ocular region is hindered by the protective layers that encapsulate the eyes, it has always been a major problem to get an effective bioavailability of the active drug in the ocular region due to the low precorneal resident time of most of the ocular delivery systems specifically convention once such as ointment, solution and suspension, as a result, most of the delivery systems are not capable of effectively treating ocular diseases. Several works have and are being carried out to overcome this problem one of which is using in-situ forming polymeric systems. Ocular In-situ gelling systems are a novel class of ocular drug delivery systems that are initially in a solution form but instantaneously gets converted into a viscous gel upon introduction or installation in the ocular cavity from which the active drugs get released in a sustained manner. This sol-to-gel phase transition depends upon various factors like change in pH, ion presence and change in temperature. Gel formed after the transformation has preferred viscosity along with bio-adhesive property, which increases the gel’s resident time in the ocular area and also releases the drug in a prolonged and sustained manner unlike conventional eye drops and ointments. This review emphasizes various ocular in-situ systems namely, pH triggered, Ion activated, and Temperature triggered systems which have prolonged residence time in the cul-de-sac area of the eye, hence increasing the ocular bioavailability.
Keywords: In-situ gel, Ocular Drug delivery, Ocular Bioavailability, Polyme
Na2.32Co1.84(SO4)(3) as a new member of the alluaudite family of high-voltage sodium battery cathodes
Electrochemical energy storage has recently seen tremendous emphasis being placed on the large-scale (power) grid storage. Sodium-ion batteries are capable of achieving this goal with economic viability. In a recent breakthrough in sodium-ion battery research, the alluaudite framework (Na2Fe2(SO4)(3)) has been reported, with the highest Fe3+/Fe2+ redox potential (ca. 3.8 V, Barpanda, et al., Nat. Commun., 2014, 5, 4358). Exploring this high-voltage sodium insertion system, we report the discovery of Na2+2xCo2-x(SO4)(3) (x = 0.16) as a new member of the alluaudite class of cathode. Stabilized by low-temperature solid-state synthesis (T <= 350 degrees C),this novel Co-based compound assumes a monoclinic structure with C2/c symmetry, which undergoes antiferromagnetic ordering below 10.2 K. Isotypical to the Fe-homologue, it forms a complete family of solid-solution Na2+2x(Fe1-yCoy)(2-x)(SO4)(3) y = 0-1]. Ab initio DFT analysis hints at potential high voltage operation at 4.76-5.76 V (vs. Na), depending on the degree of desodiation involving a strong participation of the oxygen sub-lattice. With the development of safe organic electrolytes, Na2+2xCo2-x(SO4)(3) can work as a cathode material (similar to 5 V) for sodium-ion batteries
Na2.44Mn1.79(SO4)(3): a new member of the alluaudite family of insertion compounds for sodium ion batteries
Sodium-ion batteries have been extensively pursued as economic alternatives to lithium-ion batteries. Investigating the polyanion chemistry, alluaudite structured Na2Fe2II(SO4)(3) has been recently discovered as a 3.8 V positive electrode material (Barpanda et al., Nature Commun., 5: 4358, 2014). Registering the highest ever Fe-III/Fe-II redox potential (vs. Na/Na+) and formidable energy density, it has opened up a new polyanion family for sodium batteries. Exploring the alluaudite family, here we report isotypical Na2+2xMn2-xII(SO4)(3) (x = 0.22) as a novel high-voltage cathode material for the first time. Following low-temperature (ca. 350 degrees C) solid-state synthesis, the structure of this new alluaudite compound has been solved adopting a monoclinic framework (s.g. C2/c) showing antiferromagnetic ordering at 3.4 K. Synergising experimental and ab initio DFT investigation, Na2+2xMn2-xII(SO4)(3) has been found to be a potential high-voltage (ca. 4.4 V) cathode material for sodium batteries