• Journal of the Korea Society of Computer and Information
• /
• v.16 no.1
• /
• pp.143-151
• /
• 2011

Plaintext and key are independent in the existing block cipher. Also, encryption/decryption is performed by using structural features. Therefore, the external environment of suggested mixed cryptographic algorithm is identical with the existing ones, but internally, features of the existing block cipher were meant to be removed by making plaintext and key into dependent functions. Also, to decrease the loads on the authentication process, authentication add-on with dependent characteristic was included to increase the use of symmetric cryptographic algorithm. Through the simulation where the proposed cryptosystem was implemented in the chip level, we show that our system using the shorter key length than the length of the plaintext is two times faster than the existing systems.

• Journal of KIISE:Computer Systems and Theory
• /
• v.29 no.5
• /
• pp.284-290
• /
• 2002

We propose a new authenticated encryption scheme that does not require any block encryption algorithm. Our scheme is based on the Horster-Michels-Petersen authenticated encryption scheme, and it uses a technique in the Bae~Deng signcryption scheme so that the sender's signature can be verified by an arbitrary third party. Since our scheme does not use any block encryption algorithm, we can reduce the code size in its implementation. The computation and communication costs of the proposed scheme are almost the same as those of the Bao-Deng scheme that uses a block encryption algorithm. Our scheme also satisfies all the security properties such as confidentiality, authenticity and nonrepudiation.

• Convergence Security Journal
• /
• v.16 no.7
• /
• pp.85-91
• /
• 2016

Block cipher is one of the prominent and important elements in cryptographic systems and study on the minimal construction is a major theme in the cryptographic research. Even and Mansour motivated by the study suggested a kind of block cipher called the Even-Mansour scheme in the early 1990s. It is a very simple cipher with one permutation and two secret keys. There have been many studies on the Even-Mansour scheme and security analysis of the scheme. We explain the Even-Mansour scheme and simplify those attacks on the Even-Mansour scheme with mathematical language. Additionally, we show that Pollard's rho attack to the discrete logarithm problem can be used to attack the Even-Mansour scheme with the same complexity of the Pollard's rho attack.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.237-240
• /
• 2012

This paper describes an implementation of ARIA crypto algorithm which is a KS (Korea Standards) block cipher algorithm. The ARIA crypto-core supports three master key lengths of 128/192/256-bit specified in the standard and the four modes of operation including ECB, CBC, CTR and OFB. To reduce hardware complexity, a hardware sharing is employed, which shares round function in encryption/decryption module with key initialization module. The ARIA crypto-core is verified by FPGA implementation, the estimated throughput is about 1.07 Gbps at 167 MHz.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.3
• /
• pp.485-494
• /
• 2012

The block cipher HIGHT is designed suitable for low-resource hardware implementation. It established as the TTA standard and ISO/IEC 18033-3 standard. In this paper, we propose a differentail fault attack against the block cipher HIGHT. In the proposed attack, we assume that an attacker is possible to inject a random byte fault in the input value of the 28-th round. This attack can recover the secret key by using the differential property between the original ciphertext and fault cipher text pairs. Using 7 and 12 error, our attack recover secret key within a few second with success probability 87% and 51%, respectively.

• Convergence Security Journal
• /
• v.5 no.3
• /
• pp.23-32
• /
• 2005

This paper presents a 128-bit Reversible Cellular Automata (RCA) based lightweight block cipher for Ubiquitous computing security. To satisfy resource-constraints for Ubiquitous computing, it is designed as block architecture based on Cellular Automata with high pseudo-randomness. Our implementation requires 704 clock cycles and consumes 2,874 gates for encryption of a 128-bit data block. In conclusion, the processing time outperformed that of AES and NTRU by 31%, and the number of gate was saved by 20%. We evaluate robustness of our implementation against both Differential Cryptanalysis and Strict Avalanche Criterion.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1997.11a
• /
• pp.303-314
• /
• 1997

계산능력이 제한된 8비트 마이크로프로세서에 적합하도록 모든 기본 연산을 8비트 단위로 처리하는, 블록 크기는 64비트, 키 크기는 128비트인, Feistel 구조의 블록 암호 알고리즘을 제시한다. 이 알고리즘의 안전도는 잘 알려진 two-key triple-DES[ANSI86]나 IDEA[Lai92]와 비견할 만하며, 처리속도는 single-DES[NBS77]보다도 10∼20배 빠르다. 본 논문에서는 이 알고리즘의 설계원칙 및 안전성 분석에 대하여 설명하였고, 다른 알고리즘과의 통계적 특성 및 성능에 대해서도 비교하였다.

• Review of KIISC
• /
• v.16 no.3
• /
• pp.63-74
• /
• 2006

본 논문에서는 한국 산업규격 KS 표준 블록암호 알고리즘인 ARIA의 핵심논리들을 64비트 프로세서 환경에서 효율적으로 구현하는 방법을 제안하고, 제안된 방법으로 구현된 ARIA를 대표적인 64비트 마이크로프로세서인 Intel Pentium4 x64, Intel Itanium, Intel XEON(EM64T)을 이용하여 그 효율성을 평가하였으며, 32비트 프로세서에 적합하게 구현된 ARIA와 효율성을 비교하고 문제점을 분석하였다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2001.11a
• /
• pp.403-406
• /
• 2001

본 논문에서는 차세대 표준 알고리즘(AES: Advanced Encryption Standard)인 Rijndael 알고리즘의 고속화를 FPGA로 구현하였다. Rijndael 알고리즘은 미국 상무부 기술 표준국(NIST)에 의해 2000년 10월에 차세대 표준으로 선정된 블록 암호 알고리즘이다. FPGA(Field Programmable Gate Array)는 아키텍쳐의 유연성이 가장 큰 장점이며, 근래에는 성능면에서도 ASIC에 비견될 정도로 향상되었다. 본 논문에서는 128비트 키 길이와 블록 길이를 가지는 암호화(Encryption)블럭을 Xilinx VirtexE XCV812E-8-BG560 FPGA에 구현하였으며 약 15Gbits/sec의 성능(throughput)을 가진다. 이는 현재까지 발표된 FPGA Rijndael 알고리즘의 구현 사례 중 가장 빠른 방법 중의 하나이다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.2
• /
• pp.391-404
• /
• 2022

Aron Gohr proposed a cryptanalysis method based on deep learning technology for the lightweight block cipher Speck. This is a method that enables a chosen plaintext attack with higher accuracy than the classical differential cryptanalysis. In this paper, by using the probability distribution, we analyze the mechanism of such deep learning based cryptanalysis and propose the results applied to the lightweight block cipher Simon. In addition, we examine that the probability distributions of the predicted values of the neural networks within the cryptanalysis working processes are different depending upon the characteristics of round functions of Speck and Simon, and suggest a direction to improve the efficiency of the neural distinguisher which is the core technology of Aron Gohr's cryptanalysis.