• Journal of Families and Better Life
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• v.30 no.1
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• pp.55-64
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• 2012

This study examined the mediation effect of life satisfaction between aggression and loneliness. The subjects were two hundred and eighty fifth-year elementary school and second-year middle school adolescents in Seoul. Data were analyzed by using the t-test, Pearson's correlation and regression. Major findings were as follows: First, when it comes to aggressiveness, the fifth graders showed a significantly higher degree of personal attack, whereas the eighth graders were found to show more expression of anger. The fifth graders scored higher than the eighth graders in each subcategory of life satisfaction. No significant difference was found in the category of loneliness. Second, the fifth graders showed a positive relationship among verbal attack, personal attach, expression of anger and loneliness, whereas the eighth graders showed a positive relationship between expression of anger and loneliness. The two age groups, in turn, also exhibited some differences in the relationship between loneliness and life satisfaction. Third, we found that life satisfaction is a complete parameter between aggressiveness and loneliness in the fifth graders. In the case of the eighth graders, life satisfaction turned out to be a partial parameter between aggressiveness and loneliness. This perhaps indicates that adolescents with similar levels of aggressiveness might show different degrees of loneliness, depending on whether they have positive attitudes toward their lives and whether they feel satisfied with their lives.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3587-3591
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• 2011

The reactions of O,O-diethyl Z-S-aryl phosphorothioates with X-benzylamines are kinetically investigated in dimethyl sulfoxide at $85.0^{\circ}C$. The Hammett (log $k_2$ vs ${\sigma}x$) and Br$\ddot{o}$nsted [log $k_2$ vs $pK_a$(X)] plots are biphasic concave downwards for substituent X variations in the nucleophiles with a break point at X = H. The signs of the cross-interaction constants (${\rho}xz$) are positive for both the strongly and weakly basic nucleophiles. Considerably great magnitude of ${\rho}xz$ (= 6.56) value is observed with the weakly basic nucleophiles, while ${\rho}xz$ = 0.91 with the strongly basic nucleophiles. Proposed reaction mechanism is a stepwise process with a rate-limiting leaving group expulsion from the intermediate involving a backside nucleophilic attack with the strongly basic nucleophiles and a frontside attack with the weakly basic nucleophiles. The kinetic results are compared with those of the benzylaminolysis of O,O-diphenyl Z-S-aryl phosphorothioates.

• ETRI Journal
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• v.37 no.3
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• pp.584-594
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• 2015

To date, many different kinds of logic styles for hardware countermeasures have been developed; for example, SABL, TDPL, and DyCML. Current mode-based logic styles are useful as they consume less power compared to voltage mode-based logic styles such as SABL and TDPL. Although we developed TPDyCML in 2012 and presented it at the WISA 2012 conference, we have further optimized it in this paper using a binary decision diagram algorithm and confirmed its properties through a practical implementation of the AES S-box. In this paper, we will explain the outcome of HSPICE simulations, which included correlation power attacks, on AES S-boxes configured using a compact NMOS tree constructed from either SABL, CMOS, TDPL, DyCML, or TPDyCML. In addition, to compare the performance of each logic style in greater detail, we will carry out a mutual information analysis (MIA). Our results confirm that our logic style has good properties as a hardware countermeasure and 15% less information leakage than those secure logic styles used in our MIA.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.107-112
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• 2000

In this paper, we study a security of HEA(Hangul Encryption Algorithm) against differential cryptanalysis. HEA, which is 1,024bits input/output and 56bits key size, has the same structure as DES(Data Encyption Standard) only for Korean characters to be produced in ciphertexts. An encryption algorithm should be developed to meet certain critria such as input/ouput dependencies, correlation, avalanche effects, etc. However HEA uses the same S-Boxes as DES does and just expands the plaintext/ciphertext sizes . We analysize HEA with a differential cryptanalysis and present two results. The number of rounds of HEA has not been determined in a concrete basis of cryptanalysis and we show a chosen plintext attack of 10 round reduced HEA with a diffe- rential cryptanalysis characteristic.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4508-4530
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• 2021

Today distributed data storage service are being widely used. However lack of proper means of security makes the user data vulnerable. In this work, we propose a Randomized Block Size (RBS) model for secure data storage in distributed environments. The model work with multifold block sizes encrypted with the Chinese Remainder Theorem-based RSA (C-RSA) technique for end-to-end security of multimedia data. The proposed RBS model has a key generation phase (KGP) for constructing asymmetric keys, and a rand generation phase (RGP) for applying optimal asymmetric encryption padding (OAEP) to the original message. The experimental results obtained with text and image files show that the post encryption file size is not much affected, and data is efficiently encrypted while storing at the distributed storage server (DSS). The parameters such as ciphertext size, encryption time, and throughput have been considered for performance evaluation, whereas statistical analysis like similarity measurement, correlation coefficient, histogram, and entropy analysis uses to check image pixels deviation. The number of pixels change rate (NPCR) and unified averaged changed intensity (UACI) were used to check the strength of the proposed encryption technique. The proposed model is robust with high resilience against eavesdropping, insider attack, and chosen-plaintext attack.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.2
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• pp.83-92
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• 2013

RSA-CRT is a widely used algorithm that provides high performance implementation of the RSA-signature algorithm. Many previous studies on each operation step have been published to verify the physical leakages of RSA-CRT when used in smart devices. This paper proposes SAED (subtraction algorithm analysis on equidistant data), which extracts sensitive information using the event information of the subtraction operation in a reduction algorithm. SAED is an attack method that uses algorithm-dependent power signal changes. An adversary can extract a key using differential power analysis (DPA) of the subtraction operation. This paper indicates the theoretical rationality of SAED, and shows that its results are better than those of other methods. According to our experiments, only 256 power traces are sufficient to acquire one block of data. We verify that this method is more efficient than those proposed in previously published studies.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.771-776
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• 2008

The main purpose in having a control surface on a ship is to control the motion of it. It is the important element to determine the maneuvering characteristics of the ship. In this paper, the measured results has been compared with each other to predict the performance characteristics of flapped rudder's 2-dimensional section at $Re=3.0{\times}10^4$ using 2-frame grey level cross correlation PIV method. The side force of the rudder could be mainly improved by the lift force at 10 degrees angle of attack and the drag force at 20 degrees angle of attack. The separation point and boundary layer could be controlled by the change of the only flap's angle at 10 degrees angle of attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.215-223
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• 2019

The recent trend of cyber attack threat is mainly APT (Advanced Persistent Threat) attack. This attack is a combination of hacking techniques to try to steal important information assets of a corporation or individual, and social engineering hacking techniques aimed at human psychological factors. Spear phishing attacks, one of the most commonly used APT hacking techniques, are known to be easy to use and powerful hacking techniques, with more than 90% of the attacks being a key component of APT hacking attacks. The existing research for cyber security threat defense is mainly focused on the technical and policy aspects. However, in order to preemptively respond to intelligent hacking attacks, it is necessary to study different aspects from the viewpoint of social engineering. In this study, we analyze the correlation between human personality type (DISC) and cyber security threats, focusing on spear phishing attacks, and present countermeasures against security threats from a new perspective breaking existing frameworks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.27-35
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• 2009

Differential Power Analysis (DPA) based on the statistical characteristics of collected signals has been known as an efficient attack for uncovering secret key of crypto-systems. However, the attack performance of this method is affected very much by the temporal misalignment and the noise of collected side channel signals. In this paper, we propose a new method based on wavelet analysis to surmount the temporal misalignment and the noise problem simultaneously in DPA. The performance of the proposed method is then evaluated while analyzing the power consumption signals of Micro-controller chips during a DES operation. The experimental results show that our proposed method based on wavelet analysis requires only 25% traces compared with those of the previous preprocessing methods to uncover the secret key.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.75-86
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• 2023

The guided missiles and decoy systems that have been developed have been likened to a spear and shield. When a new attack system appears, another defense system is developed, and the attack system is once again upgraded to neutralize it. Now, due to the limitations of the decoy system, guided weapons have become the main force of both the defense and attack systems. Also, these systems have been expanded to use Space systems as a means of defending against a guided weapon system that is too fast for terrestrial-based systems. Induced weapon systems started at the sub-sonic level, and have become so important that their speeds have become super-sonic and hyper-sonic. The concept of Space has been included in the range of guided missiles, and satellite systems have become essential elements of guided missiles. Focusing on the correlation between the guided missile system and the satellite system, we analyze the characteristics of modern guided munitions and the direction of development of the guided weapons system.