A Bit-Vector Differential Model for the Modular Addition by a Constant

ARX algorithms are a class of symmetric-key algorithms constructed by Addition, Rotation, and XOR, which achieve the best software performances in low-end microcontrollers. To evaluate the resistance of an ARX cipher against differential cryptanalysis and its variants, the recent automated methods employ constraint satisfaction solvers, such as SMT solvers, to search for optimal characteristics. The main difficulty to formulate this search as a constraint satisfaction problem is obtaining the differential models of the non-linear operations, that is, the constraints describing the differential probability of each non-linear operation of the cipher. While an efficient bit-vector differential model was obtained for the modular addition with two variable inputs, no differential model for the modular addition by a constant has been proposed so far, preventing ARX ciphers including this operation from being evaluated with automated methods. In this paper, we present the first bit-vector differential model for the n-bit modular addition by a constant input. Our model contains O(log_2(n)) basic bit-vector constraints and describes the binary logarithm of the differential probability. We also represent an SMT-based automated method to look for differential characteristics of ARX, including constant additions, and we provide an open-source tool ArxPy to find ARX differential characteristics in a fully automated way. To provide some examples, we have searched for related-key differential characteristics of TEA, XTEA, HIGHT, and LEA, obtaining better results than previous works. Our differential model and our automated tool allow cipher designers to select the best constant inputs for modular additions and cryptanalysts to evaluate the resistance of ARX ciphers against differential attacks

A Bit-Vector Differential Model for the Modular Addition by a Constant and its Applications to Differential and Impossible-Differential Cryptanalysis

ARX algorithms are a class of symmetric-key algorithms constructed by Addition, Rotation, and XOR. To evaluate the resistance of an ARX cipher against differential and impossible-differential cryptanalysis, the recent automated methods employ constraint satisfaction solvers to search for optimal characteristics or impossible differentials. The main difficulty in formulating this search is finding the differential models of the non-linear operations. While an efficient bit-vector differential model was obtained for the modular addition with two variable inputs, no differential model for the modular addition by a constant has been proposed so far, preventing ARX ciphers including this operation from being evaluated with automated methods. In this paper, we present the first bit-vector differential model for the $n$-bit modular addition by a constant input. Our model contains $O(\log_2(n))$ basic bit-vector constraints and describes the binary logarithm of the differential probability. We describe an SMT-based automated method that includes our model to search for differential characteristics of ARX ciphers including constant additions. We also introduce a new automated method for obtaining impossible differentials where we do not search over a small pre-defined set of differences, such as low-weight differences, but let the SMT solver search through the space of differences. Moreover, we implement both methods in our open-source tool \texttt{ArxPy} to find characteristics and impossible differentials of ARX ciphers with constant additions in a fully automated way. As some examples, we provide related-key impossible differentials and differential characteristics of TEA, XTEA, HIGHT, LEA, SHACAL-1, and SHACAL-2, which achieve better results compared to previous works

Omega-3 fatty acid supplements improve the cardiovascular risk profile of subjects with metabolic syndrome, including markers of inflammation and auto-immunity

OBJECTIVE Fish-oil contains high concentrations of omega-3 fatty acids that have been shown to have anti-inflammatory properties. We have evaluated the effects of purified omega-3 fatty acid supplements on several anthropometric and biochemical parameters, including heat shock protein (Hsp) 27 antibody titres in subjects with metabolic syndrome. METHODS Subjects (n = 120) with metabolic syndrome (mean age of 52.9 +/- 11.9 years) were randomly allocated to one of two groups: sixty subjects were given 1 gram of fish oil as a single capsule, containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid daily for 6 months. Control subjects did not receive any supplementation over the same period. RESULTS The study was completed by 47 subjects in the intervention group and 42 subjects in the control group. Treatment with omega 3 supplements was associated with a significant fall in body weight (P < 0.05), systolic blood pressures (P < 0.05), serum low density lipoprotein cholesterol (P < 0.05), and total cholesterol (P < 0.05), triglycerides (P < 0.05), high-sensitivity C-reactive protein (hs-CRP) (P < 0.01), and Hsp27 antibody titres (P < 0.05). No significant changes were observed in the control group. CONCLUSION It appears that omega 3 improves the cardiovascular risk profile of subjects with metabolic syndrome, having effects on weight, systolic blood pressure, lipid profile and markers of inflammation and autoimmunit

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Capsid Modified Bluetongue Virus 16 (BTV16) as a Virulytic Oncotherapy Agent

Objective: Using potential viruses to destroy cancer cells has a long history, but recent advances in molecular biology raised hopes for successful use of these viruses again. Methods: Octreotate sequence was inserted into the neutralization region (R1& R2) in vp2 protein of capsid segment in 10 segmented genome of BTV in 304 - 368 position. T7 BTV RNA transcripts were extracted. Cancerous cultured cells were transfected with wild and modified BTV to recover BTV with cDNA-derived genome segments. Results: The results of all the performed experiments revealed that treatment of AGS cell lines with VP2 modified BTV16, which targeted cell surface of cancerous cells, significantly increased apoptosis in cancer infected cells. Conclusions: Modified VP2 BTV16 may be used as a potential virulytic oncotherapy agent in AGS cells. Keywords: Bluetongue Virus, Oncotherapy, Virulytic, AG

A Bit-Vector Differential Model for the Modular Addition by a Constant

ARX algorithms are a class of symmetric-key algorithms constructed by Addition, Rotation, and XOR, which achieve the best software performances in low-end microcontrollers. To evaluate the resistance of an ARX cipher against differential cryptanalysis and its variants, the recent automated methods employ constraint satisfaction solvers, such as SMT solvers, to search for optimal characteristics. The main difficulty to formulate this search as a constraint satisfaction problem is obtaining the differential models of the non-linear operations, that is, the constraints describing the differential probability of each non-linear operation of the cipher. While an efficient bit-vector differential model was obtained for the modular addition with two variable inputs, no differential model for the modular addition by a constant has been proposed so far, preventing ARX ciphers including this operation from being evaluated with automated methods. In this paper, we present the first bit-vector differential model for the n-bit modular addition by a constant input. Our model contains O(log2(n)) basic bit-vector constraints and describes the binary logarithm of the differential probability. We also represent an SMT-based automated method to look for differential characteristics of ARX, including constant additions, and we provide an open-source tool ArxPy to find ARX differential characteristics in a fully automated way. To provide some examples, we have searched for related-key differential characteristics of TEA, XTEA, HIGHT, and LEA, obtaining better results than previous works. Our differential model and our automated tool allow cipher designers to select the best constant inputs for modular additions and cryptanalysts to evaluate the resistance of ARX ciphers against differential attacks

Metabolic syndrome may not be a good predictor of coronary artery disease in the Iranian population: population-specific definitions are required

The inability of two definitions of metabolic syndrome (MS) to predict the presence of coronary artery disease (CAD) in a non-Caucasian population was demonstrated. Angiography was used as the gold standard method for identifying patients with (cases) or without (controls) CAD. It is possible that the current definitions of MS are not appropriate for some non-Caucasian populations