• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.1127-1132
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• 2002

LFSR보다 CA가 랜덤성이 우수한 패턴들을 효율적으로 생성함이 알려지면서 그 응용분야가 점차적으로 확대되어가고 있다. Nongroup CA는 해쉬함수의 생성, 암호알고리즘, 이미지 압축 등에 응용되고 있다. 그러나 CA가 생성하는 패턴의 분석이 용이하지 못하였다. 본 논문에서는 선형 nongroup CA의 일반적인 성질과 여원 벡터가 선형 nongroup CA의 0-트리의 0이 아닌 상태인 경우 이로부터 유도되는 여원 TPNCA의 상태들의 행동을 분석하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1063-1066
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• 2005

셀룰라 오토마타(Cellular Automata, 이하 CA)는 LFSR의 대안으로 제안되었으나 일반화와 분석이 어려워 거의 이뤄지지 않고 있다. 본 논문에서는 특별한 전이규칙을 가지는 그룹 CA에서 각각의 여원벡터에 대응하여 유도되는 여원 그룹 CA의 구조를 분석한다. 여기서 분석하는 그룹 여원 CA는 전체 상태가 그룹 CA의 최대 주기나 그것의 2배가 되는 같은 길이의 사이클들로 분리된다. 이러한 성질은 암호학에서 키 공유 프로토콜에 유용한 성질로 사용될 수 있다.

• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.549-555
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• 2003

CA is cost-effective to generate pseudorandom patterns than LFSR. Based on the effectiveness of a CA based pseudorandom pattern generator, CA have been employed successfully in several applications. Especially Nongroup CA is applied to efficient hash function generation, cryptography and image compression. In this paper we analyze the properties of TPNCA and by using basic paths in the 0-tree of a linear TPNCA we analyze the structure of the state-transition graph. Also by showing the structure of the complemented CA which have the acyclic state of the 0-tree as the complement vector is isomorphic to the structure of the original TPNCA, we reduce the time in analyzing the CA-states.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.570-573
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• 2001

본 논문에서는 선형 TPMACA C의 0-tree에서 0이 아닌 상태를 여원벡터로 갖는 CA C'를 분석하여 C의 모든 상태가 C'의 어느 곳에 있는지를 밝혔으며 또한 C의 상태전이 그래프에서 한 경로만 알면 나머지 상태론 알 수 있음을 밝혔다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.365-370
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• 2001

In this paper, we analyze behavior of complemented CA derived from a linear Two-Predecessor MACA(TPMACA) and obtain the state-transition diagram of complemented CA by using a basic path in the 0-Dee of a linear TPMACA.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.375-378
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• 2001

본 논문에서는 선형 MACA의 0-트리의 한 경로를 기본 경로로 하여 나머지 다른 트리를 구성하고 여원벡터를 선형 MACA의 하나의 상태로 해석하였을 때 상태전이그래프에서 놓이는 위치에 따라 선형 MACA로부터 유도된 여원을 갖는 CA의 모든 트리를 구성하는 알고리즘을 제안한다. 주어진 전이행렬과 여원벡터를 가지는 additive CA의 트리를 구성함에 있어 보다 빠르게 구성할 수 있는 알고리즘을 제시한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.1001-1008
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• 2019

A high-quality pseudorandom sequence generation is an important part of many cryptographic applications, including encryption protocols. Therefore, a pseudorandom number generator (PRNG) is an essential element for generating key sequences in a cryptosystem. A PRNG must effectively generate a large, high-quality random data stream. It is well known that the bitstreams output by the CA-based PRNG are more random than the bitstreams output by the LFSR-based PRNG. In this paper, we prove that the complemented CA derived from 90/150 maximum length cellular automata(MLCA) is a MLCA to design a PRNG that can generate more secure bitstreams and extend the key space in a secret key cryptosystem. Also we give a method for calculating the cell positions outputting a nonlinear sequence with maximum period in complemented MLCA derived from a 90/150 MLCA and a complement vector.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1565-1572
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• 2006

Recently with the ever increasing growth of data communication, the need for security and privacy has become a necessity. The advent of wireless communication and other handheld devices like Personal Digital Assistants and smart cards have made the implementation of cryptosystems a major issue. The Cellular Automata(CA) can be programmed to implement hardware sharing between the encryption and decryption. In this paper, we give conditions for a linear hybrid cellular automata with 60, 102 or 204 to be a linear hybrid group cellular automata C. And we present the conditions which the complemented hybrid group cellular automata C' with complement vectors derived from C has maximum equal lengths in the state transition diagram of C' Also we analyze the relationship among cycles of C' These results generalize Mukhopadhyay's results.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.293-302
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• 2016

In this paper we analyze the CA formed by combining the uniform 102 CA $\mathbb{C}_u$ and the m-cell 90/150 hybrid CA $\mathbb{C}_h$ whose characteristic polynomial is $(x+1)^m$. We analyze cycle structures of complemented group CA derived from $\mathbb{C}_u$ and propose a condition of complemented CA dividing the entire state space into smaller cycles of equal lengths. And we analyze the cycle structure of complemented group CA $\mathbb{C}^{\prime}$ derived from the CA $\mathbb{C}$ formed by combining $\mathbb{C}_u$ and $\mathbb{C}_h$ with complement vector F such that $(T+I)^{q-1}F{\neq}0$ where $(x+1)^q$ is the minimal polynomial of $\mathbb{C}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6C
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• pp.361-367
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• 2011

In this paper, we propose encryption method to using complemented MLCA(Maximum Length Cellular Automata) based on NBCA(Null Boundary CA) and 2D CAT (Two-Dimensional Cellular Automata Transform) for efficient image encryption. The encryption method is processed in the following order. First, a transition matrix T is created using the Wolfram Rule matrix. Then, the transition matrix T is multiplied to the original image that is intended to be encrypted, which transfers the pixel values of the original image. Furthermore, the converted original image goes through a XOR operation with complemented vector F to convert into a complemented MLCA applied image. Then, the gateway value is set and 2D CAT basis function is created. Also, the 2D CAT is encrypted by multiplying the created basis function to the complemented MLCA applied image. Lastly, the stability analysis verifies that proposed method holds a high encryption quality status.