• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.164-166
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• 2016

PRESENT/ARIA/AES의 3가지 블록 암호 알고리즘을 지원하는 암호 프로세서를 MPW(Multi-Project Wafer)칩으로 구현하였다. 설계된 블록 암호 칩은 PRmo(PRESENT with mode of operation) 코어, AR_AS(ARIA_AES) 코어, AES-16b 코어로 구성된다. PRmo는 80/128-비트 마스터키와, ECB, CBC, OFB, CTR의 4가지 운영모드를 지원한다. 128/256-비트 마스터키를 사용하는 AR_AS 코어는 서로 내부 구조가 유사한 ARIA와 AES를 통합하여 설계하였다. AES-16b는 128-비트 마스터키를 지원하고, 16-비트 datapath를 채택하여 저면적으로 구현하였다. 설계된 암호 프로세서를 FPGA검증을 통하여 정상 동작함을 확인하였고, 0.18um 표준 셀 라이브러리로 논리 합성한 결과, 100 KHz에서 52,000 GE로 구현이 되었으며, 최대 92 MHz에서 동작이 가능하다. 합성된 다중 암호 프로세서는 MPW 칩으로 제작될 예정이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.155-157
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• 2016

한국 표준 블록암호 알고리듬 ARIA(Academy, Research Institute, Agency)와 미국 표준인 AES(Advanced Encryption Standard) 알고리듬은 128-비트 블록 길이를 지원하고 SPN(substitution permutation network) 구조를 특징으로 가져 서로 유사한 형태를 지닌다. 본 논문에서는 ARIA와 AES를 선택적으로 수행하는 ARIA-AES 통합 프로세서를 효율적으로 구현하였다. Verilog HDL로 설계된 ARIA-AES 통합 프로세서를 Virtex5 FPGA로 구현하여 정상 동작함을 확인하였고, $0.18{\mu}m$ 공정의 CMOS 셀 라이브러리로 100KHz의 동작주파수에서 합성한 결과 39,498 GE로 구현되었다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.3-10
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• 2007

In this paper we present related-key differential attacks on the block-wise stream cipher TWOPRIME. We construct various related-key differentials of TWOPRIME and use them to show that recovering related keys of TWOPRIME can be performed with a data complexity of $2^{14}$ known plaintext blocks and a time complexity of $2^{38}$ 8-bit table lookups.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.5 no.1
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• pp.25-36
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• 1995

Differential Cryptanalysis(DC) and Linear Cryptanalysis(LC) are considered to be efficient attack methods which could be applied to DES and other DES-like private key Cryptosystems. This paper analyzes the DC and LC attack to DES and design a 80-bit block Cipher (80-DES) which could be strong against DC and LC Attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.91-99
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• 2004

Iwata et al. analyzed the pseudorandomness of the block cipher Serpent which is a SPN-type transformation. In this parer, we introduce a generalization of the results, which can be applied to any SPN-type transformation. For the purpose, we give several explicit definitions and prove our main theorems. We will also apply our theorems to several SPN-type transformations including Serpent, Crypton and Rijndael.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.478-493
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• 2024

In this paper, the Mixed Integer Linear Programming (MILP) model is improved for searching differential characteristics of block cipher Midori-64, and 4 search strategies of differential path are given. By using strategy IV, set 1 S-box on the top of the distinguisher to be active, and set 3 S-boxes at the bottom to be active and the difference to be the same, then we obtain a 5-round differential characteristics. Based on the distinguisher, we attack 12-round Midori-64 with data and time complexities of 2⁶³ and 2^103.83, respectively. To our best knowledge, these results are superior to current ones.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.137-145
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• 2003

Nowadays, people can communicate with each other on any time at my place by development of wireless communications. But, the openness of mobile communications Poses serious security threats and the security is necessary on mobile communications to support the secure communication channel. The most commonly method is stream cipher for mobile communications. Generally, this stream cipher is implemented by LFSR(Linear Feedback Shift Register). On this paper proposes the modified mechanism of the S box is usually used in block cipher to advance security og the stream cipher and this mechanism is the modified three one in consideration og the randomness. Generally, S box that is function with nonlinear property makes data more strong by attack. The randomness test of the proposed algorithm is used Ent Pseudorandom Number Sequence Test Program and by the test result it proves that it has better randomness and serial correlation value than the based stream cipher on respective test.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.183-194
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• 2004

The proliferation of the Internet and the rapid progress of wire/wireless communication technology makes security of digital images more and more important since the exchanges of digital images occur more and more frequently. And as the tight relationship between chaos theory and cryptography, many researches for development of new encryption systems based on chaotic maps have been widely progressed recently. In this paper, we propose a digital image encryption system based on both one-dimensional PLCM(Piecewise Linear Chaotic Map) and two-dimensional baker map. This proposed system is a product cipher that contains a perturbance-based chaotic stream cipher based on ID PLCM and a chaotic block cipher based on 2D baker map and is very high secure and easily implementable cipher having both a good confusion property and a good diffusion property. And with test results, we showed this system is very secure against statistical attacks.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.4
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• pp.101-106
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• 2021

Quantum algorithms and quantum computers can break the security of many of the ciphers we currently use. If Grover's algorithm is applied to a symmetric key cipher with n-bit security level, the security level can be lowered to (n/2)-bit. In order to apply Grover's algorithm, it is most important to optimize the target cipher as a quantum circuit because the symmetric key cipher must be implemented as a quantum circuit in the oracle function. Accordingly, researches on implementing AES(Advanced Encryption Standard) or lightweight block ciphers as quantum circuits have been actively conducted in recent years. In this paper, korean lightweight block cipher LEA was optimized and implemented as a quantum circuit. Compared to the previous LEA quantum circuit implementation, quantum gates were used more, but qubits were drastically reduced, and performance evaluation was performed for this tradeoff problem. Finally, we evaluated quantum resources for applying Grover's algorithm to the proposed LEA implementation.

• 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.