• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2517-2524
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• 2012

This paper describes an efficient implementation of KS(Korea Standards) block cipher algorithm ARIA. The ARIA crypto-processor supports three master key lengths of 128/192/256-bit and four modes of operation including ECB, CBC, OFB and CTR. A hardware sharing technique, which shares round function in encryption/decryption with key initialization, is employed to reduce hardware complexity. It reduces about 20% of gate counts when compared with straightforward implementation. The ARIA crypto-processor is verified by FPGA implementation, and synthesized with a $0.13-{\mu}m$ CMOS cell library. It has 46,100 gates on an area of $684-{\mu}m{\times}684-{\mu}m$ and the estimated throughput is about 1.28 Gbps at 200 MHz@1.2V.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.551-560
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• 2006

Security in WPAN is one of the most fundamental issues to overcome the barrier of wireless environment. Although piconet security mechanisms have been defined in the WPAN standards, many remains open and are left for implementation. Koinonia is a high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. In Koinonia WPAN, a piconet consists of one master and more than one slave, and piconet security mechanisms is not defined at all. Therefore, we propose a robust piconet security mechanism for secure communications between slaves in a piconet. Based on security requirements analysis, our proposed protocols are shown to meet the security needs for Koinonia high-rate WPAN.

• Geomechanics and Engineering
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• v.8 no.2
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• pp.283-303
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• 2015

To research and analyze the differential settlements of foundations specifically, site investigations of existing railways and metro were firstly carried out. Then, the centrifugal test was used to observe differential settlements in different position between foundations on the basis of investigation. The theoretical model was established according to the stress diffusion method and Fourier method to establish an analytical solution of embankment differential settlement between different foundations. Finally, theoretical values and experimental values were analyzed comparatively. The research results show that both in horizontal and vertical directions, evident differential settlement exists in a limited area on both sides of the vertical interface between different foundations. The foundation with larger elastic modulus can transfer more additional stress and cause relatively less settlement. Differential settlement value decreases as the distance to vertical interface decreases. In the vertical direction of foundation, mass differential settlement also exists on both sides of the vertical interface and foundation with larger elastic modulus can transfer more additional stress. With the increase of relative modulus of different foundations, foundation with lower elastic modulus has larger settlement. Meanwhile, differential settlement is more obvious. The main error sources in theoretical and experimental values include: (a) different load form; (b) foundation characteristics differences; (c) modulus conversion; (d) effect of soil internal friction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2550-2572
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• 2023

Epidemiological survey is an important means for the prevention and control of infectious diseases. Due to the particularity of the epidemic survey, 1) epidemiological survey in epidemic prevention and control has a wide range of people involved, a large number of data collected, strong requirements for information disclosure and high timeliness of data processing; 2) the epidemiological survey data need to be disclosed at different institutions and the use of data has different permission requirements. As a result, it easily causes personal privacy disclosure. Therefore, traditional access control technologies are unsuitable for the privacy protection of epidemiological survey data. In view of these situations, we propose a black box-assisted fine-grained hierarchical access control scheme for epidemiological survey data. Firstly, a black box-assisted multi-attribute authority management mechanism without a trusted center is established to avoid authority deception. Meanwhile, the establishment of a master key-free system not only reduces the storage load but also prevents the risk of master key disclosure. Secondly, a sensitivity classification method is proposed according to the confidentiality degree of the institution to which the data belong and the importance of the data properties to set fine-grained access permission. Thirdly, a hierarchical authorization algorithm combined with data sensitivity and hierarchical attribute-based encryption (ABE) technology is proposed to achieve hierarchical access control of epidemiological survey data. Efficiency analysis and experiments show that the scheme meets the security requirements of privacy protection and key management in epidemiological survey.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1163-1170
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• 2016

A hardware implementation of ultra-lightweight block cipher algorithm PRESENT which was specified as a standard for lightweight cryptography ISO/IEC 29192-2 is described. The PRESENT crypto-processor supports two key lengths of 80 and 128 bits, as well as four modes of operation including ECB, CBC, OFB, and CTR. The PRESENT crypto-processor has on-the-fly key scheduler with master key register, and it can process consecutive blocks of plaintext/ciphertext without reloading master key. In order to achieve a lightweight implementation, the key scheduler was optimized to share circuits for key lengths of 80 bits and 128 bits. The round block was designed with a data-path of 64 bits, so that one round transformation for encryption/decryption is processed in a clock cycle. The PRESENT crypto-processor was verified using Virtex5 FPGA device. The crypto-processor that was synthesized using a $0.18{\mu}m$ CMOS cell library has 8,100 gate equivalents(GE), and the estimated throughput is about 908 Mbps with a maximum operating clock frequency of 454 MHz.

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.49-61
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• 2005

The dynamic modulus of hot mix asphalt can be determined according to the different combinations of testing temperature and loading frequency. The superposition rule is adapted to get the master curve of dynamic modulus for each hot mix asphalt. There are couple of different methods to get the shift factor which is a key for making the master curve. In this paper, Arrehnius, 2002 AASHTO, and experimental method was employed to get the master curve. Evaluation of dynamic modulus for 25mm base course of hot mix asphalt with granite aggregate and two asphalt binders(AP-3 and AP-5) was carried out. Superpave Level 1 Mix Design with gyratory compactor was adopted to determine the optimum asphalt binder content(OAC) and the measured ranges of OAC were between 4.1% and 4.4%. UTM was used for laboratory test. The dynamic modulus and phase angle were determined by testing on UTM, with 5 different testing temperature(-10, 5, 20, 40, & $55^{\circ}C$) and 5 different loading frequencies(0.05, 0.1, 1, 10, 25 Hz). Using the measured dynamic modulus and phase angle, the input parameters of Sigmoidal function equation to represent the master curve were determined and these will be adopted in FEM analysis for asphalt pavements. The shift factor and activation energy for determination of master curve were calculated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.401-403
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• 2015

This paper describes an efficient hardware design of 128-bit block cipher algorithm LEA(lightweight encryption algorithm). In order to achieve area-efficient and low-power implementation, round block and key scheduler block are optimized to share hardware resources for encryption and decryption. The key scheduler register is modified to reduce clock cycles required for key scheduling, which results in improved encryption/decryption performance. FPGA synthesis results of the LEA processor show that it has 2,364 slices, and the estimated performance for the master key of 128/192/256-bit at 113 MHz clock frequency is about 181/162/109 Mbps, respectively.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1059-1070
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• 2018

The block cipher Zorro is designed to reduce the implementation cost for side-channel countermeasure. It has a structure similar to AES, but the number of S-Boxes used is small. However, since the master key is used as the round key, it can be vulnerable to related key attacks. In this paper, we show key recovery attacks on Zorro using related-key differential characteristics. In addition, the related key differential characteristics are fatal when Zorro is used as the base block cipher of the hash function. In this paper, we describe how these characteristics can be linked to collision attacks in the PGV models.

• 대한공업교육학회지
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• v.31 no.1
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• pp.1-22
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• 2006

The purpose of this study is to measure the level and importance of the key competencies of technical high school students in order to improve their key competencies. The subject was 12 teachers in charge of school-to-work education in a technical high school and 7 managers responsible for an apprentice in a company. The results of this study showed there was a difference in perception of the key competencies between teachers in charge of school-to-work education and managers responsible for that part in a company. Especially, both of two groups, teacher group and manager group, estimated apprentice's comprehension ability of the English documents low and also regarded its importance as low. So the comprehension ability of the English documents needs to be reconsidered as the key competencies. It appeared that the reading comprehension ability of Chinese characters and the ability of listening courteously needed to be added to the existing key competencies. To cultivate them, the key competencies should be examined accurately which technical high school students have to master. And on the basis of this, an instrument to measure the key competencies needs to be developed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.404-406
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• 2015

This paper describes a small-area hardware implementation of the block cipher algorithm CLEFIA-128 which supports for 128-bit master key. A compact structure using single data processing block is adopted, which shares hardware resources for round transformation and the generation of intermediate values for round key scheduling. In addition, data processing and key scheduling blocks are simplified by utilizing a modified GFN(generalized Feistel network) and key scheduling scheme. The CLEFIA-128 crypto-processor is verified by FPGA implementation. It consumes 823 slices of Virtex5 XC5VSX50T device and the estimated throughput is about 105 Mbps with 145 MHz clock frequency.