• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.39-47
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• 2005

This paper proposes and analyzes the MAC(Message Authentication Code) algorithm that is used for the transition integrity and the entity authentication of message. The MAC algorithm uses the DES algorithm which has 64-bit block and 56-bit key and we compare the security according to 64-bit and 32-bit length of MAC value. Moreover, we use the SEED algorithm which has 128-bit block and 128-bit key and compare the security according to 128-bit and 64-bit length of MAC value. We analyze the security the forgery attack according to length of message and length of MAC value. this paper, a coarse-to-fine optical flow detection method is proposed. Provided that optical flow gives reliable approximation to two-dimensional image motion, it can be used to recover the three-dimensional motion. but usually to get the reliable optical flows are difficult. The proposed algorithm uses Horn's algorithm (or detecting initial optical flow, then Thin Plate Spline is introduced to warp a image frame of the initial optical flow to the next image frame. The optical flow for the warped image frame is again used iteratively until the mean square error between two image sequence frames is lowered. The proposed method is experimented for the real moving Picture image sequence. The proposed algorithm gives dense optical flow vectors.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.65.1-70
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• 2000

최근 인터넷 사용자의 증가와 인터넷을 이용한 전자상거래가 활발해지면서 TCP/IP 통신 보안에대한 많은 연구들이 진행되고 있다. 이러한 연구들중 SSL(Secure Socket Layer) 은 인증 및 보안 프로토콜로서 인터넷을 이용한 통신 보안에 가장 많이 사용되고있는 방법이다. 본 논문에서는 국내 암호 알고리즘의 표준으로 채택된 SEED 알고리즘을 SSL에 적용하여 서버와 클라이언트의 통신을 128bits 암호화할 수 있는 SSL-Proxy 프로그램을 구현하였으며, Windows 와 Unix 시스템에 모두 적용 가능하도록 모듈화하였다.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.113-119
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• 2003

Both the highly developed computing environment and the rapid increase of the internet users enable the present web based cluster system accounting service to help many users access to numerous data at high speed. However, the information security of users and data is also as important as the convenience of the systematic environment. Especially, the significance of damage to the individuals and organizations resulted from the data outflow, hacking and malicious coding has risen up to one of the most essential problems in the internet service business. In this study, I suggest a more safe web based cluster system accounting service solution applying SEED, the Korean Telecommunications Technology Association (TTA) standard encryption algorithm.

• Review of KIISC
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• v.14 no.5
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• pp.69-77
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• 2004

ISO/IEC JTC1/SC27의 WG2는 정보보안기술을 위한 관련 메커니즘의 표준을 만드는 Working Group이다. 본 고에서 소개하는 28차 싱가포르회의(2004. 4) 이전에 개최된 21차 동경회의(2000. 10)와 22차 오슬로회의(2001. 4)에 대해서는 동 학회지 제11권 1호(2001년 2월)와 제11권 3호(2001년 6월)를 참고하고, 23차 서울회의와 WG2 중 블록암호 표준화 동향에 대해서는 제11권 6호(2001년 12월), 24차 베를린회의(2002. 4)에 대해서는 제12권 2호(2002. 4)를 참고하기 바란다. 본 고에서는 금년 4. 19(월)∼23(금)에 걸쳐 싱가포르 Conrad Continental Singapore에서 개최된 제 28차 WG2 회의의 활동 결과를 소개하고, 아울러 암호알고리즘의 표준화 정책변경으로 지난 2000년부터 SEED의 국제표준 채택까지의 표준화 활동을 정리하고 향후 차세대 암호 기법의 국제표준화를 위한 제언을 한다. 또한 이번 회의 기간 중 아시아권 보안 기술 및 제품의 보급 확산을 위한 RAISS(Regional Asia Information Security Standards) 포럼의 동향과 대응 방안에 대하여 제안한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.4
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• pp.59-68
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• 2006

Although the cryptographic algorithms in IC chip such as smart card are secure against mathematical analysis attack, they are susceptible to side channel attacks in real implementation. In this paper, we analyze the security of smart card using a developed experimental tool which can perform power analysis attacks and fault insertion attacks. As a result, raw smart card implemented SEED and ARIA without any countermeasure is vulnerable against differential power analysis(DPA) attack. However, in fault attack about voltage and clock on RSA with CRT, the card is secure due to its physical countermeasures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.661-664
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• 2003

Trade-off of sorority and speed always exists in the latest network environment. Recently, developed security processors is improved very performance, and sorority connection algorithms of a lot of part were embodied by hardware. This high speed security processor is essential ingredient in string network security solution equipment development that require very big band width. In this paper, we wish to describe about design and implementation of 10 Giga VPN equipments. In this system, embodied 10 Giga to use Cavium company's Nitrox-II processor, and supports two SP14-2 interface and PCI interface. All of the password algorithm that password algorithm that support is used in common use VPN equipment for compatibility with common use VPN equipment are supported and support SEED algorithm developed in domestic. Designed to support IPsec and SSL protocol, and supports all of In-Line structure that is profitable in high speed transaction and the Look-Aside structure that is profitable in practical use degree of NPU(Network Processor Unit).

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.107-111
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• 2005

As Internet grows rapidly and next electronic commerce applications increase, the security is getting more important. Information security to provide secure and reliable information transfer is based on cryptography technique. The proposed ISEED(Improved SEED) algorithm based on block cryptography algorithm which belongs to secret-key algorithm. In terms of efficiency, the round key generation algorithm has been proposed to reduces the time required in encryption and decryption. The algorithm has been implemented as follow. 128-bit key is divided into two 64-bit group to rotate each of them 8-bit on the left side and right side, and then basic arithmetic operation and G function have been applied to 4-word outputs. In the process of converting encryption key which is required in decryption and encryption of key generation algorithm into sub key type, the conversion algorithm is analyzed. As a result, the time consumed to encryption and decryption is reduced by minimizing the number of plain text required differential analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.250-256
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• 2017

Recently, the use of mobile devices has increased in order to provide a variety of services, and thus there has been a surge in the number of application malicious attacks on the Android platform. To resolve the problem, the domestic financial sector has been introducing the app anti-tamper solution based on cryptographic algorithms. However, since the capacity of apps installed in smartphones continues to increase and environments with limited resources as wearables and IoTs spread, there are limitations to the processing speed of the anti-tamper solutions. In this paper, we propose a novel anti-tamper solution by using lightweight hash function LEA and LSH. We also present the test results of a simulation program that implements this method and compare the performance with anti-tamper solutions based on the previous cryptographic algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.916-926
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• 2003

The encryption of packets increases delay and delay jitter that may degrade the quality of service (QoS) in real-time communications. So, we analyzed the delay jitter, delay, and interval delay between consecutive packets which were encrypted by the DES, 3DES, SEED and AES algorithms in this study. The interval delay and jitter of three algorithms such as the DES, SEED, AES were similar to the results of no encryption. But in the case of 3DES, the encryption of packets increases the variance of interval delay and jitter in comparison with other algorithms. we also analyzed properties of security and an efficiency of RTP security between SRTP and H.235.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.123-136
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• 2004

In this paper, complexity and regularity of polynomial multiplication over $GF({2^n})$ are defined by using Hamming weight of rows and columns of the matrix ever GF(2) which represents polynomial multiplication. It is shown experimentally that in order to construct the block cipher robust against differential cryptanalysis, polynomial multiplication of substitution layer and the permutation layer should have high complexity and high regularity. With result of the experiment, a way of constituting S box and G function is suggested in the block cipher whose structure is similar to SEED, which is KOREA standard of 128-bit block cipher. S box can be formed with a nonlinear function and an affine transform. Nonlinear function must be strong with differential attack and linear attack, and it consists of an inverse number over $GF({2^8})$ which has neither a fixed pout, whose input and output are the same except 0 and 1, nor an opposite fixed number, whose output is one`s complement of the input. Affine transform can be constituted so that the input/output correlation can be the lowest and there can be no fixed point or opposite fixed point. G function undergoes linear transform with 4 S-box outputs using the matrix of 4${\times}$4 over $GF({2^8})$. The components in the matrix of linear transformation have high complexity and high regularity. Furthermore, G function can be constituted so that MDS(Maximum Distance Separable) code can be formed, SAC(Strict Avalanche Criterion) can be met, and there can be no weak input where a fixed point an opposite fixed point, and output can be two`s complement of input. The primitive polynomials of nonlinear function affine transform and linear transformation are different each other. The S box and G function suggested in this paper can be used as a constituent of the block cipher with high security, in that they are strong with differential attack and linear attack with no weak input and they are excellent at diffusion.