• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1279-1285
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• 2014

In this paper, we propose on image encryption method which uses NC(Non-linear Cycle) and 2D CAT(Two-Dimensional Cellular Automata Transform) in sequence to encrypt medical images. In terms of the methodology, we use NC to generate a pseudo noise sequence equal to the size of the original image. We then conduct an XOR operation of the generated sequence with the original image to conduct level 1 NC encryption. Then we set the proper Gateway Values to generate the 2D CAT basis functions. We multiply the generated basis functions by the altered NC encryption image to conduct the 2nd level 2D CAT encryption. Finally, we verify that the proposed method is efficient and extremely safe by conducting an analysis of the key spatial and sensitivity analysis of pixels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.663-670
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• 2009

In this paper, we propose the image encryption method which gradually uses NFSR(Non-linear Feedback Shift Register) and 20 CAT(Two-Dimensional Cellular Automata Transform). The encryption method is processed in the following order. First, NFSR is used to create a PN(pseudo noise) sequence, which matches the size of the original image. Then, the created sequence goes through a XOR operation with the original image and process the encipherment. Next, the gateway value is set to produce a 20 CAT basis function. The produced basis function is multiplied by encryption image that has been converted to process the 20 CAT encipherment. Lastly, the results of the experiment which are key space analysis, entropy analysis, and sensitivity analysis verify that the proposed method is efficient and very secure.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.212-216
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• 2011

Digital watermarking has gained importance in recent years in copyright protection and multimedia. This paper proposes a secure and novel watermarking system based on complemented Maximum Length Cellular Automata (MLCA) and Two-Dimension Cellular Automata Transform (2D CAT). In this watermarking scheme, the original watermark is first encrypted by complemented MLCA with the private keys, and then the encrypted watermark is embedded into the CAT domain of the cover image, at last use the inverse CAT for the transformed image, the watermarked image is obtained. Experiment results show that this new method is more secure and provides robust performance against watermarking attacks.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.336-339
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• 2012

본 논문에서는 비선형 MLCA(Maximum Length Cellular Automata)와 1D CAT(One-Dimensional Cellular Automata Transform)를 이용하여 의료 영상 암호화 방법을 제안한다. 암호화 방법은 먼저, Wolfram Rule 행렬에 의해 전이행렬 T를 생성한다. 그 후, 암호화하려는 원 영상에 생성된 전이 행렬 T를 곱하여 원 영상의 픽셀 값을 변환한다. 또한 변환된 원 영상을 여원 벡터 F와 XOR 연산하여 비선형 MLCA가 적용된 영상으로 변환한다. 다음, 게이트웨이 값을 설정하여 1D CAT 기저함수를 생성한다. 그리고, 비선형 MLCA가 적용된 영상에 생성된 1D CAT 기저함수를 곱하여 암호화를 한다. 마지막으로 키 공간 분석을 통하여 제안한 방법이 높은 암호화 수준의 성질을 가졌음을 검증한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8C
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• pp.689-696
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• 2010

The goal of this paper is to present a novel method for protecting digital image using 2-D cellular automata transform (CAT). A copyright and transform coefficients are used to generate a new content-based copyright and an original digital image is distributed without any hidden copyright. The parameter, which is called gateway value, for 2-D CAT is consisted of rule number, initial configuration, lattice length, number of neighbors, and etc. Since 2-D CAT has various gateway values, it is more secure than conventional methods. The proposed algorithm is verified using attacked images such as filtering, cropping, JPEG compression, and rotation for robustness.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.393-396
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• 2010

A secure and novel watermarking system based on complemented Maximum Length Cellular Automata (MLCA) and Two-Dimension Cellular Automata Transform (2D CAT) is proposed. In this watermarking scheme, the original watermark which is first encrypted by complemented MLCA with the private keys, and the encrypted watermark is embedded into the CAT domain of the cover image. Experiment results show that this new method is more secure and provides robust performance against watermarking attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6177-6200
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• 2018

In order to achieve the goal of protecting medical images, some existing watermark techniques for medical image protection mainly focus on improving the invisibility and robustness properties of the method, in order to prevent unnecessary medical disputes. This paper proposes a novel copyright method for medical image protection based on visual secret sharing (VSS) and cellular automata transform (CAT). This method uses the protected medical image feature as well as VSS and a watermark to produce the ownership share image (OSI). The OSI is used for medical image verification and must be registered to a certified authority. In the watermark extraction process, the suspected medical image is used to generate a master share image (MSI). The watermark can be extracted by combining the MSI and the OSI. Different from other traditional methods, the proposed method does not need to modify the medical image in order to protect the copyright of the image. Moreover, the registered OSI used to verify the ownership and its appearance display meaningful information, facilitating image management. Finally, the results of the final experiment can prove the effectiveness of our method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1767-1778
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• 2009

A robust and secure InIm(Integral imaging)-based 3D watermarking scheme using cellular automata transform (CAI) is proposed. In the InIm-based 3D watermarking scheme, the elemental image array (EIA) watermark for the target watermark which has to be detected, is synthesized from the computational pickup process of InIm and embedded in a cover image. The EIA watermark can provide a robust reconstruction of the target watermark However, the 3D property of the EIA watermark causes a weakening of the security. To overcome this problem, the proposed method uses the CAT domain to embed and extract the EIA watermark in the cover image. The use of CAT significantly improves the security for our watermarking algorithm using a single secure key only. Experiments are presented to show that the proposed scheme shows robust and secure performances against various attacks.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.439-446
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• 2019

In this paper, we propose a encryption method using C-MLCA and 1D CAT to secure medical image for efficiently. First, we generate a state transition matrix using a Wolfram rule and create a sequence of maximum length. By operating the complemented vector, it converts an existing sequence to a more complex sequence. Then, we multiply the two sequences by rows and columns to generate C-MLCA basis images of the original image size and go through a XOR operation. Finally, we will get the encrypted image to operate the 1D CAT basis function created by setting the gateway values and the image which is calculated by transform coefficients. By comparing the encrypted image with the original image, we evaluate to analyze the histogram and PSNR. Also, by analyzing NPCR and key space, we confirmed that the proposed encryption method has a high level of stability and security.