• Smart Media Journal
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• v.12 no.9
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• pp.9-18
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• 2023

Black box cryptography is a cryptographic scheme based on a hardware encryption device, operating under the assumption that the device and the user can be trusted. However, with the increasing use of cryptographic algorithms on unreliable open platforms, the threats to black box cryptography systems have become even more significant. As a consequence, white box cryptography have been proposed to securely operate cryptographic algorithms on open platforms by hiding encryption keys during the encryption process, making it difficult for attackers to extract the keys. However, unlike traditional cryptography, white box-based encryption lacks established specifications, making challenging verify its structural security. To promote the safer utilization of white box cryptography, CHES organizes The WhibOx Contest periodically, which conducts safety analyses of various white box cryptographic techniques. Among these, the Differential Computation Analysis (DCA) attack proposed by Bos in 2016 is widely utilized in safety analyses and represents a powerful attack technique against robust white box block ciphers. Therefore, this paper analyzes the research trends in white box block ciphers and provides a summary of DCA attacks and relevant countermeasures. adhering to the format of a research paper.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.387-392
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• 2016

This study was conducted to ameliorate the productive performance of Hanwoo cow using hill pasture grazing system. Twenty seven animals aged 9 were designed to divide with 3 groups which were Control (restricted concentrate and hay for 5 months), T1 (restricted concentrate and pasture grazing ad libitum for 5 months) and T2 (restricted concentrate, 30 g/head of mineral nutrients and pasture grazing ad libitum for 5 months). Average daily gains increased higher in the order of T2, Control and T1. The conception rate of Control, T1 and T2 after artificial insemination during post-grazing period were 88.9%, 100%, 100%, respectively. In conclusion, the results indicated that hill pasture grazing system might enhance not only the productive performance of Hanwoo cow but also profit for conventional feeding system.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.699-710
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• 2007

This study was conducted to estimate the genetic parameters and their relationships with weight traits of the steers and bulls in the Hanwoo population. The data used were weights and weight gain of performance and progeny test from 6,024 heads of Hanwoo. Data of performance test consisted of total 3,737 heads raised from August, 1989 to September, 2005. The number of the records of progeny test was total 2,287 heads from August, 1996 to June, 2004. The heritabilities and correlations for the body weights at the ages of 6 months, 12 months and 24 months and average daily gain were estimated by DFREML. Overall means and standard deviations of body weights at 6 and 12 months of age and average daily gain(ADG) from the data of performance test were 181.72±30.22kg, 351.48±40.24kg, 998.07±153.84g, respectively. Overall means and standard deviations of body weights at 6, 12, and 24 month of age and ADG from the data of progeny test were 169.18±32.82kg, 229.37±44.57kg, 570.45±64.36kg and 739.41± 172.14g, respectively. The heritability estimates of the body weight at 6, 12 month and ADG from the performance test were 0.54±0.06, 0.60±0.06 and 0.23±0.04, respectively. The heritability estimates of the body weight at 6, 12, 24 month and ADG from the progeny test were 0.80±0.08, 0.50±0.07, 0.46±0.07 and 0.07±0.03, respectively.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.3
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• pp.157-167
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• 2021

Lead (Pb) is one of the key trace elements, exhibiting a peculiar partitioning behavior into silicate melts in contact with minerals. Partitioning behaviors of Pb between silicate mineral and melt have been known to depend on melt composition and thus, the atomic structures of corresponding silicate liquids. Despite the importance, detailed structural studies of Pb-bearing silicate melts are still lacking due to experimental difficulties. Here, we explored the effect of lead content on the atomic structures, particularly the evolution of silicate networks in Pb-bearing sodium metasilicate ([(PbO)_x(Na₂O)_1-x]·SiO₂) glasses as a model system for trace metal bearing natural silicate melts, using ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy. As the PbO content increases, the ²⁹Si peak widths increase, and the maximum peak positions shift from -76.2, -77.8, -80.3, -81.5, -84.6, to -87.7 ppm with increasing PbO contents of 0, 0.25, 0.5, 0.67, 0.86, and 1, respectively. The ²⁹Si MAS NMR spectra for the glasses were simulated with Gaussian functions for Qⁿ species (SiO₄ tetrahedra with n BOs) for providing quantitative resolution. The simulation results reveal the evolution of each Qⁿ species with varying PbO content. Na-endmember Na₂SiO₃ glass consists of predominant Q² species together with equal proportions of Q¹ and Q³. As Pb replaces Na, the fraction of Q² species tends to decrease, while those for Q¹ and Q³ species increase indicating an increase in disproportionation among Qⁿ species. Simulation results on the ²⁹Si NMR spectrum showed increases in structural disorder and chemical disorder as evidenced by an increase in disproportionation factor with an increase in average cation field strengths of the network modifying cations. Changes in the topological and configurational disorder of the model silicate melt by Pb imply an intrinsic origin of macroscopic properties such as element partitioning behavior.