• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.233-242
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• 2009

This paper intend to show the affect of the intra-prediction on the typical digital watermarking method and the fact that the watermarking method has very low effectiveness when it is performed for the intra-frames of H.264. The target watermarking method was the one for imperceptibility and robustness and was assumed to be performed during the intra-compression process by the H.264 technique. Also this method was assumed to insert watermark data and to extract it for certification if needed. The problem is that the resulting data from the re-engineering of the watermark insertion process to extract the watermark data is different from the one before. We experimentally showed that it stems from the intra-prediction itself. That is, we showed that the resulting image data from only compression without watermarking changes if it is re-compressed by the same conditions as the first compression and it is because the intra-prediction modes as well as the coefficient values change. Also, we applied one blind and one semi-blind watermarking methods to show that the typical attacks after watermarking makes this problem much more serious and lowers the effectiveness of the watermarking method dramatically. Therefore we concluded by considering the experimental data that a typical watermarking method which has been researched so far cannot guarantee the effectiveness of intra-frame watermarking and it is highly required to developed a new kind of methodologies.

• Cross-Cultural Studies
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• v.38
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• pp.89-113
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• 2015

This paper explores the work of mourning of 9/11 in the United States, focusing on the project of building the National September 11 Memorial managed by the Lower Manhattan Development Corporation(LMDC) and the War on Terror declared by the George W. Bush administration in the wake of 9/11. This paper first looks at the project of building the Natioanl September 11 Memorial and considers what was at stake in achieving this project. It also examines the limitations of the project. This paper argues that, in spite of the efforts to mourn the victims in significant and meaningful ways, the work of mourning in the memorial project fails at least in two respects. First, the memorial project "began so soon" right after 9/11 that the victims' families were not given enough time to mourn their loved ones. Second, the project were permeated with American nationalism and patriotism, which made the 316 non-American victims of 9/11 invisible and forgotten. Then, it goes on to examine the War on Terror because the War on Terror epitomized the failure of mourning due to these causes. In his address to the nation delivered on the very day of 9/11, President George W. Bush stated that "America was targeted for the attack because we're the brightest beacon for freedom and opportunity in the world" and that the terrorists failed to threaten America into chaos. He also stated that America is in "the war against terrorism." These statements were a futile reassertion of the illusion of American invulnerability and a prohibition of mourning in favor of violent military responses to 9/11. American nationalism also underlies Bush's official naming of September 11 as "Patriot Day." The victims were sacrificed because they were at the site when terrorists attacked, which implies that their death had nothing to do with American patriotism. Naming September 11 as Patriot Day was an act of imbuing the absurdity of the victims' death with a false meaning and an act of forgetting the non-American victims. The failure of the work of mourning of 9/11 consisted in the inability to recognize human vulnerability and interdependence and the inability to mourn not only American victims but also non-American victims killed in 9/11 and the War on Terror. A meaningful and significant mourning could be possible when we realizes that all human beings are exposed to one another and their lives are interdependent on one another. September Eleventh Families for Peaceful Tomorrows well demonstrated this kind of mourning. When most Americans supported violent retaliations, Peaceful Tomorrows made pleas for nonviolent responses to 9/11. Turning their grief into action for peace, its members work "to create a safer and more peaceful world for everyone," not only for Americans. Their effort to mourn in meaningful and nonviolent ways delivers the message that a disaster like 9/11 should not happen anywhere.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.5
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• pp.1179-1189
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• 2019

Cyber security evaluation is a series of processes that estimate the level of risk of assets and systems through asset analysis, threat analysis and vulnerability analysis and apply appropriate security measures. In order to prepare for increasing cyber attacks, systematic cyber security evaluation is required. Various indicators for measuring cyber security level such as CWSS and CVSS have been developed, but the quantitative method to apply appropriate security measures according to the risk priority through the standardized security evaluation result is insufficient. It is needed that an Scoring system taking into consideration the characteristics of the target assets, the applied environment, and the impact on the assets. In this paper, we propose a quantitative risk assessment model based on the analysis of existing cyber security scoring system and a method for quantification of assessment factors to apply to the established model. The level of qualitative attribute elements required for cyber security evaluation is expressed as a value through security requirement weight by AHP, threat influence, and vulnerability element applying probability. It is expected that the standardized cyber security evaluation system will be established by supplementing the limitations of the quantitative method of applying the statistical data through the proposed method.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.262-269
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• 2008

In this paper, we propose an image watermark method using multiple decoding keys. The advantages of this method are that the multiple original images are reconstructed by using multiple decoding keys in the same watermark image, and that the quality of reconstructed images is clearly enhanced based on the idea of Walsh code without any side lobe components in the decoding process. The zero-padded original images, multiplied with random-phase pattern to each other, are Fourier transformed. Encoded images are then obtained by taking the real-valued data from these Fourier transformed images. The embedding images are obtained by the product of independent Walsh codes, and these spreaded phase-encoded images which are multiplied with new random-phase images. Also we obtain the decoding keys by multiplying these random-phase images with the same Walsh code images used in the embedding images. A watermark image is then made from the linear superposition of the weighted embedding images and a cover image, which is multiplied with a new independent Walsh code. The original image is simply reconstructed by the inverse-Fourier transform of the despreaded image of the multiplication between the watermark image and the decoding key. Computer simulations demonstrate the efficiency of the proposed watermark method with multiple decoding keys and a good robustness to the external attacks such as cropping and compression.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.875-888
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• 2021

In this paper, we search integral distinguishers of lightweight block cipher PIPO and propose a key recovery attack on 8-round PIPO-64/128 with the obtained 6-round distinguishers. The lightweight block cipher PIPO proposed in ICISC 2020 is designed to provide the efficient implementation of high-order masking for side-channel attack resistance. In the proposal, various attacks such as differential and linear cryptanalyses were applied to show the sufficient security strength. However, the designers leave integral attack to be conducted and only show that it is unlikely for PIPO to have integral distinguishers longer than 5-round PIPO without further analysis on Division Property. In this paper, we search integral distinguishers of PIPO using a MILP-aided Division Property search method. Our search can show that there exist 6-round integral distinguishers, which is different from what the designers insist. We also consider linear operation on input and output of distinguisher, respectively, and manage to obtain totally 136 6-round integral distinguishers. Finally, we present an 8-round PIPO-64/128 key recovery attack with time complexity 2^124.5849 and memory complexity of 2⁹³ with four 6-round integral distinguishers among the entire obtained distinguishers.

• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.11-17
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• 2021

The 30mm anti-aircraft gun has been developed with various types of weapon systems such as protective, protective complex, and wheel-type anti-aircraft artillery. The role of this anti-aircraft gun is an important anti-aircraft weapon in charge of air defense. Anti-aircraft weapons are tasked with defending the airspace from aircraft attacks. In particular, anti-aircraft weapons are organized in combination with mechanized units. And anti-aircraft weapons are prone to attack by enemies because they operate on the front lines of the battlefield. The enemy is expected to attack our troops by covering up or concealing as much as possible in order to increase their viability. Therefore, this study analyzed whether our 30mm anti-aircraft bullets could subdue the enemy in cover. This study analyzed the performance of 30mm anti-aircraft bullets using the M&S technique. For this study, live shooting and simulation method by M&S were used for the experiment. In this study, steel plate and plywood were used for the live shooting experiment. In addition, in the simulation process through M&S, this study used the PRODAS model, AUTODYN model, and Split-x model to analyze the trajectory, penetration, and fragmentation capability of 30mm anti-aircraft bullets. According to the experimental results, it has been proven that 30mm anti-aircraft bullets can destroy enemy armored vehicles. 30mm anti-aircraft bullets succeeded in quickly subduing enemies concealed in general buildings or forests. In this way, it was possible to minimize damage to allies in advance.

• Convergence Security Journal
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• v.21 no.2
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• pp.57-66
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• 2021

Deep neural networks (DNNs) provide excellent performance for image, speech, and pattern recognition. However, DNNs sometimes misrecognize certain adversarial examples. An adversarial example is a sample that adds optimized noise to the original data, which makes the DNN erroneously misclassified, although there is nothing wrong with the human eye. Therefore studies on defense against adversarial example attacks are required. In this paper, we have experimentally analyzed the success rate of detection for adversarial examples by adjusting various parameters. The performance of the ensemble defense method was analyzed using fast gradient sign method, DeepFool method, Carlini & Wanger method, which are adversarial example attack methods. Moreover, we used MNIST as experimental data and Tensorflow as a machine learning library. As an experimental method, we carried out performance analysis based on three adversarial example attack methods, threshold, number of models, and random noise. As a result, when there were 7 models and a threshold of 1, the detection rate for adversarial example is 98.3%, and the accuracy of 99.2% of the original sample is maintained.

• Convergence Security Journal
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• v.21 no.2
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• pp.11-18
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• 2021

To protect tangible and intangible assets, most of the companies are conducting information protection monitoring by using various security equipment in the IT service network. As the security equipment that needs to be protected increases in the process of upgrading and expanding the service network, it is difficult to monitor the possible exposure to the attack for the entire service network. As a countermeasure to this, various studies have been conducted to detect external attacks and illegal communication of equipment, but studies on effective monitoring of the open service ports and construction of illegal communication monitoring system for large-scale service networks are insufficient. In this study, we propose a framework that can monitor information leakage and illegal communication attempts in a wide range of service networks without large-scale investment by analyzing 'Netflow statistical information' of backbone network equipment, which is the gateway to the entire data flow of the IT service network. By using machine learning algorithms to the Netfllow data, we could obtain the high classification accuracy of 94% in identifying whether the Telnet service port of operating equipment is open or not, and we could track the illegal communication of the damaged equipment by using the illegal communication history of the damaged equipment.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.29-39
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• 2021

As damages to individuals, private sectors, and businesses increase due to newly occurring cyber attacks, the underlying network security problem has emerged as a major problem in computer systems. Therefore, NIDS using machine learning and deep learning is being studied to improve the limitations that occur in the existing Network Intrusion Detection System. In this study, a deep learning-based NIDS model study is conducted using the Convolution Neural Network (CNN) algorithm. For the image classification-based CNN algorithm learning, a discrete algorithm for continuity variables was added in the preprocessing stage used previously, and the predicted variables were expressed in a linear relationship and converted into easy-to-interpret data. Finally, the network packet processed through the above process is mapped to a square matrix structure and converted into a pixel image. For the performance evaluation of the proposed model, NSL-KDD, a representative network packet data, was used, and accuracy, precision, recall, and f1-score were used as performance indicators. As a result of the experiment, the proposed model showed the highest performance with an accuracy of 85%, and the harmonic mean (F1-Score) of the R2L class with a small number of training samples was 71%, showing very good performance compared to other models.

• Korean Journal of Labor Studies
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• v.24 no.2
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• pp.321-365
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• 2018

Though the British shipbuilding industry dominated the world market in the 19th century, it could not avoid the repetitive rise and fall of the unemployment following after the cyclical fluctuations. Without challenging the employers' rights to fire at will, the boilermakers maintained their own unemployment insurance in order to escape from the new poverty law system. In the beginning the craft union could continue their own unemployment insurance under the National Insurance Act of 1911, but it went into bankruptcy under the massive unemployment of the 1920s and the attacks of shipyard employers. The Act of 1911 was a step towards social solidarity in that it spread the risks beyond the occupational boundaries, applying unemployment insurance to unskilled and non-union workers, and the employer and the government also paid the premium. In the Great Depression, the shipyard trade unions demanded that the government should intervene in the shipbuilding market to provide jobs, but it was not accepted by the government. The government responded only to the another demand of the union for the maintenance, which could be achieved partially through the abnormal operation of the insurance system, abandoning the insurance principle. After all, unemployment in the shipbuilding industry was resolved only by the expansion of rearmaments and the outbreak of World War II. From the 19th century to the World War II, the craft unions did not challenge the employers' right to fire at will and did not attempt to regulate dismissal procedures or make any demands on dismissal compensations. During interwar periods rules and practices related with weak employment protection - one of the main features of the liberal employment adjustment institution - were prevalent in Britain. The principle of 'employment at will' could survive through the historical events such as the World War I, II as the operation of the unemployment insurance became the focus of the social conflicts.