• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.87-92
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• 2006

An $AB^2$ modular operation is an efficient basic operation for the public key cryptosystems and various systolic architectures for $AB^2$ modular operation have been proposed. However, these architectures have a shortcoming for cryptographic applications due to their high area complexity. Accordingly, this paper presents an partitioned $AB^2$ systolic modular multiplier over GF($2^m$). A dependency graph from the MSB $AB^2$ modular multiplication algorithm is partitioned into 1/3 to get an partitioned $AB^2$ systolic multiplier. The multiplier reduces the area complexity about 2/3 compared with the previous multiplier. The multiplier could be used as a basic building block to implement the modular exponentiation for the public key cryptosystems based on smartcard which has a restricted hardware requirements.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.736-743
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• 2020

Modular multiplication is one of the most important arithmetic operations in public-key cryptography such as elliptic curve cryptography (ECC) and RSA, and the performance of modular multiplier is a key factor influencing the performance of public-key cryptographic hardware. An efficient hardware implementation of word-based Montgomery modular multiplication algorithm is described in this paper. Our modular multiplier was designed to support eleven field sizes for prime field GF(p) and binary field GF(2k) as defined by SEC2 standard for ECC, making it suitable for lightweight hardware implementations of ECC processors. The proposed architecture employs pipeline scheme between the partial product generation and addition operation and the modular reduction operation to reduce the clock cycles required to compute modular multiplication by 50%. The hardware operation of our modular multiplier was demonstrated by FPGA verification. When synthesized with a 65-nm CMOS cell library, it was realized with 33,635 gate equivalents, and the maximum operating clock frequency was estimated at 147 MHz.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1035-1045
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• 2018

Recently, with the development of IT technology, authentication methods of users using cloud services have been diversified. However, research on providing authentication information of a user using a cloud service securely according to authority has not been make until now. In this paper, we propose a key establishment protocol which can perform split authentication using secret key and access control key according to the role authority of user in Intra cloud environment. The proposed protocol generates the access control key and secret key of the user by using the attributes of the user and the generated random number($t_1$, $t_2$), and classifies the roles according to the user's authority after generating the key. Unnecessary operation processes can be reduced. As a result of the performance evaluation, the proposed protocol guarantees the security against various type of attacks that may occur in the cloud environment because the user is authenticated by dividing the access control key and secret key. The size of the ciphertext used to establish the key could be reduced by ${\sum}+1$ more than the existing protocol.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.763-775
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• 2021

The thermal hydraulic performances of Steam Generator (SG) under both steady and transient operation conditions are of great importance for the safety and economy in nuclear power plants. In this paper, based on our self-developed SG thermal hydraulic analysis code STAF (Steam-generator Thermalhydraulic Analysis code based on Fluent), an improved new version STAF-CT (fully Coupling and Transient) is developed and introduced. Compared with original STAF, the new version code STAF-CT has two main functional improvements including "Transient" and "Fully Three Dimensional Coupling" features. In STAF-CT, a three dimensional energy transferring module is established which can achieve energy exchange computing function at the corresponding position between two sides of SG. The STAF-CT is validated against the international benchmark experiment data and the results show great agreement. Then the U-shaped SG in AP1000 nuclear power plant is modeled and simulated using STAF-CT. The results show that three dimensional flow fields in the primary side make significant effect on the energy source distribution between two sides. The development of code STAF-CT in this paper can provide an effective method for further SG high fidelity research in the nuclear reactor system.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1321-1329
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• 2017

A quantum computer, based on quantum mechanics, is a paradigm of information processing that can show remarkable possibilities of exponentially improved information processing. This paradigm can be solved in a short time by calculating factoring problem and discrete logarithm problem that are typically used in public key cryptosystems such as RSA(Rivest-Shamir-Adleman) and ECC(Elliptic Curve Cryptography). In 2013, Lei et al. proposed a secure NTRU-based key distribution protocol for quantum computing. However, Lei et al. protocol was vulnerable to man-in-the-middle attacks. In this paper, we propose a NTRU(N-the truncated polynomial ring) key distribution protocol with mutual authentication only using NTRU convolution multiplication operation in order to maintain the security for quantum computing. The proposed protocol is resistant to quantum computing attacks. It is also provided a secure key distribution from various attacks such as man-in-the middle attack and replay attack.

• Journal of the military operations research society of Korea
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• v.35 no.3
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• pp.61-79
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• 2009

It is recognized that guaranteeing the interoperability of defense complex systems(SoS: System of Systems, FoS: Family of Systems) provides an information advantage, which is one of the essential factors for determining an warfighting advantage. This study presents the defense KIP(Key Interface Profile) process for improving interoperability of defense complex systems. The KIP process is to develop key interface profiles based on the key interfaces which are identified through the analysis of architecture. The KIP developed can be leveraged to manage the interfaces of complex systems. We verify the effectiveness of the proposed KIP process through a case study based on the systems of counter-fire operation.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.362-370
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• 2013

In this paper, we propose a novel optical implementation of a 3DES algorithm based on dual XOR logic operations for a cryptographic system. In the schematic architecture, the optical 3DES system consists of dual XOR logic operations, where XOR logic operation is implemented by using a free-space interconnected optical logic gate method. The main point in the proposed 3DES method is to make a higher secure cryptosystem, which is acquired by encrypting an individual private key separately, and this encrypted private key is used to decrypt the plain text from the cipher text. Schematically, the proposed optical configuration of this cryptosystem can be used for the decryption process as well. The major advantage of this optical method is that vast 2-D data can be processed in parallel very quickly regardless of data size. The proposed scheme can be applied to watermark authentication and can also be applied to the OTP encryption if every different private key is created and used for encryption only once. When a security key has data of $512{\times}256$ pixels in size, our proposed method performs 2,048 DES blocks or 1,024 3DES blocks cipher in this paper. Besides, because the key length is equal to $512{\times}256$ bits, $2^{512{\times}256}$ attempts are required to find the correct key. Numerical simulations show the results to be carried out encryption and decryption successfully with the proposed 3DES algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.105-112
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• 2003

In this raper, we propose two simple and efficient key agreement protocols, called SEKA-H and SEKA-E, which use a pre-shared password between two parties for mutual authentication and agreeing a common session key. The SEKA-H protocol uses a hash function to verify an agreed session key. The SEKA-E Protocol, a variant of SEKA-H, uses an exponentiation operation in the verification phase. They are secure against the man-in-the-middle attack the password guessing attack and the Denning-Sacco attack and provide the perfect forward secrecy. The SEKA-H protocol is very simple in structure and provides good efficiency compared with other well-known protocols. The SEKA-E protocol is also comparable with the previous protocols.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.3-16
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• 2010

Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.12-24
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• 2023

With the improvement of laser technology, the strategic needs of efficient and precise decontamination of various components in nuclear application units can be fulfilled by laser decontamination. The surface contaminants of nuclear facilities mainly exist both as loose contaminated layer and fixed oxide layer. The types of radionuclides and contamination layer thickness are closely related to the operation status of nuclear facilities, which have an important influence on the laser decontamination process. This study reviewed the mechanism of laser surface treatment and the influence of laser process parameters on the decontamination thickness, decontamination factor, decontamination efficiency and the distribution of aerosol particle. Although multiple studies have been performed on the mechanism of laser processing and laser decontamination process, there are few studies on the microscopic process mechanism of laser decontamination and the influence of laser decontamination on surface properties. In particular, the interaction between laser and radioactive contaminants needs more research in the future.