Further observations on SIMON and SPECK families of block ciphers

SIMON and SPECK families of block ciphers are well-known lightweight ciphers designed by NSA. In this note, based on the previous investigations on SIMON, a closed formula for the squared correlations and differential probabilities of the mapping $\phi(x) = x \odot S^1(x)$ on $\mathbb{F}_2^n$ is given. From the aspects of linear and differential cryptanalysis, this mapping is equivalent to the core quadratic mapping of SIMON via rearrangement of coordinates and EA-equivalence. Based upon the proposed explicit formula, a full description of DDT and LAT of $\phi$ is provided. In the case of SPECK, as the only nonlinear operation in this family of ciphers is, addition mod $2^n$, after reformulating the formula for linear and differential probabilities of addition mod $2^n$, straightforward algorithms for finding the output masks with maximum squared correlation, given the input masks as well as the output differences with maximum differential probability, given the input differences, are presented

Prevalence and pattern of basal skull fracture in head injury patients in an academic hospital

Background: Basal skull fractures (BSFs) have been reported to be a major cause of morbidity and mortality in the literature, particularly in young male patients. However, there are limited data available on the aetiology, prevalence and patterns of such observed in South Africa. Objectives: To evaluate the prevalence and pattern of BSF in head injury patients referred to Dr George Mukhari Academic Hospital, Gauteng, South Africa. Methods: Patients of all ages with head injuries were considered for the study, and those who met the inclusion criteria were scanned using a 128-slice multidetector helical computed tomography (CT) machine after obtaining consent. Data were prospectively obtained over a 6-month period, interpreted on an advanced workstation by two readers and statistically analysed. Results: The prevalence of BSF in this study was found to be 15.2%. The majority of patients (80.5%) were under 40 years old, with a male to female ratio of 3:1. The most common aetiology of BSF was assault, which accounted for 46% of cases. The middle cranial fossa was the most frequently fractured compartment, while the petrous bone was the most commonly fractured bone. There was a statistically significant association between head injury severity and BSF, and between the number of fracture lines and associated signs of BSF (p < 0.001). The sensitivity of clinical signs in predicting BSF was 31%, while specificity was 89.3% (p = 0.004). Conclusion: The prevalence and pattern of BSF found were consistent with data from previously published studies, although, dissimilarly, assault was found to be the most common aetiology in this study

Lai-Massey Scheme Revisited

Lai-Massey scheme is a well-known block cipher structure which has been used in the design of the ciphers PES, IDEA, WIDEA, FOX and MESH. Recently, the lightweight block cipher FLY applied this structure in the construction of a lightweight $8 \times 8$ S-box from $4 \times 4$ ones. In the current paper, firstly we investigate the linear, differential and algebraic properties of the general form of S-boxes used in FLY, mathematically. Then, based on this study, a new cipher structure is proposed which we call generalized Lai-Massey scheme or GLM. We give upper bounds for the maximum average differential probability (MADP) and maximum average linear hull (MALH) of GLM and after examination of impossible differentials and zero-correlations of one round of this structure, we show that two rounds of GLM do not have any structural impossible differentials or zero-correlations. As a measure of structural security, we prove the pseudo-randomness of GLM by the H-coefficient method

Insulin-Like Growth Factor I and II mRNA Levels in Rumen Wall of Calves Fed with Different Physical Forms of Diets

This study was designed to investigate the effects of physical forms and hay contents of diets on gene expression of insulin-like growth factor (IGF) I and II in rumen epithelium of Holstein calves. Twelve male calves were assigned to 4 treatments: ground (GR), texturized (TX), pellet (PL), and ground+10% forage (GF). Calves were weaned on day 50 of age and then slaughtered on day 70 after birth. Rumen epithelial tissue samples were immediately collected for quantification of mRNA abundance. Results indicated that only IGF I expression was influenced by the dietary treatments. A significant (pIGF I expression and each of histological parameters denoted as length of rumen villi and diameter of keratinocyte layer was observed. No significant correlation between IGF II expression and rumen histological parameters was found (p&gt;0.05). Regarding the results, higher 0.05). Regarding the results, higher IGF I expression in PL and TX treatments despite the low growth rate might be due to the challenging condition of developing rumen in calves. In fact, the rumen tissue attempted to maintain rumen pH at least by induction of a higher IGF I expression

Bitwise Linear Mappings with Good Cryptographic Properties and Efficient Implementation

Linear mappings are crucial components of symmetric ciphers. A special type of linear mappings are (0,1)-matrices which have been used in symmetric ciphers such as ARIA, E2 and Camellia as diffusion layers with efficient implementation. Bitwise linear maps are also used in symmetric ciphers such as SHA family of hash functions and HC family of stream ciphers. In this article, we investigate a special kind of linear mappings: based upon this study, we propose several linear mappings with only XOR and rotation operations. The corresponding matrices of these mappings can be used in either the former case as (0,1)-matrices of maximal branch number or in the latter case as linear mappings with good cryptographic properties. The proposed mappings and their corresponding matrices can be efficiently implemented both in software and hardware

A More Explicit Formula for Linear Probabilities of Modular Addition Modulo a Power of Two

Linear approximations of modular addition modulo a power of two was studied by Wallen in 2003. He presented an efficient algorithm for computing linear probabilities of modular addition. In 2013 Sculte-Geers investigated the problem from another viewpoint and derived a somewhat explicit for these probabilities. In this note we give a closed formula for linear probabilities of modular addition modulo a power of two, based on what Schlte-Geers presented: our closed formula gives a better insight on these probabilities and more information can be extracted from it

Characterization of MDS mappings

MDS codes and matrices are closely related to combinatorial objects like orthogonal arrays and multipermutations. Conventional MDS codes and matrices were defined on finite fields, but several generalizations of this concept has been done up to now. In this note, we give a criterion for verifying whether a map is MDS or not

The Role of Protein SUMOylation in the Pathogenesis of Atherosclerosis

Atherosclerosis is a progressive, inflammatory cardiovascular disorder characterized by the development of lipid-filled plaques within arteries. Endothelial cell dysfunction in the walls of blood vessels results in an increase in vascular permeability, alteration of the components of the extracellular matrix, and retention of LDL in the sub-endothelial space, thereby accelerating plaque formation. Epigenetic modification by SUMOylation can influence the surface interactions of target proteins and affect cellular functionality, thereby regulating multiple cellular processes. Small ubiquitin-like modifier (SUMO) can modulate NFκB and other proteins such as p53, KLF, and ERK5, which have critical roles in atherogenesis. Furthermore, SUMO regulates leukocyte recruitment and cytokine release and the expression of adherence molecules. In this review, we discuss the regulation by SUMO and SUMOylation modifications of proteins and pathways involved in atherosclerosis

Application of Pseudo-Hermitian Quantum Mechanics to a Complex Scattering Potential with Point Interactions

We present a generalization of the perturbative construction of the metric operator for non-Hermitian Hamiltonians with more than one perturbation parameter. We use this method to study the non-Hermitian scattering Hamiltonian: H=p^2/2m+\zeta_-\delta(x+a)+\zeta_+\delta(x-a), where \zeta_\pm and a are respectively complex and real parameters and \delta(x) is the Dirac delta function. For regions in the space of coupling constants \zeta_\pm where H is quasi-Hermitian and there are no complex bound states or spectral singularities, we construct a (positive-definite) metric operator \eta and the corresponding equivalent Hermitian Hamiltonian h. \eta turns out to be a (perturbatively) bounded operator for the cases that the imaginary part of the coupling constants have opposite sign, \Im(\zeta_+) = -\Im(\zeta_-). This in particular contains the PT-symmetric case: \zeta_+ = \zeta_-^*. We also calculate the energy expectation values for certain Gaussian wave packets to study the nonlocal nature of \rh or equivalently the non-Hermitian nature of \rH. We show that these physical quantities are not directly sensitive to the presence of PT-symmetry.Comment: 22 pages, 4 figure