• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.116-121
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• 2022

In this paper, we propose a highly secure watermarking technique in which the watermark is multi-encrypted using the R, G, and B component pixels of color image, and then the multi-encrypted watermark is hidden in the LSB of the color image pixel. According to the technique proposed in this paper, the quality of the stego-image created by hiding the multi-encrypted watermark in the LSB of the color image is so excellent that the difference from the cover image cannot be recognized. Also, it is possible to extract the original watermark from the stego-image without loss. If the watermark is hidden in the image using the proposed technique, the security of the watermark is maintained very well because the watermark hidden in the stego-image is multi-encrypted. The proposed watermarking technique can be used in the applications such as military and intellectual property protection requiring high security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.1020-1042
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• 2019

Reversible data hiding in encrypted images (RDHEI) provides some real-time cloud applications; i.e. the cloud, acting as a data-hider, automatically embeds timestamp in the encrypted image uploaded by a content owner. Many existing methods of RDHEI only satisfy user privacy in which the data-hider does not know the original image, but leaks owner privacy in which the receiver can obtains the original image by decryption and extraction. In the literature, the method of Zhang et al. is the one providing weak content-owner privacy in which the content-owner and data-hider have to share a data-hiding key. In this paper, we take care of the stronger notion, called strong content-owner privacy, and achieve it by presenting a new reversible data hiding in encrypted images. In the proposed method, image decryption and message extraction are separately controlled by different types of keys, and thus such functionalities are decoupled to solve the privacy problem. At the technique level, the original image is segmented along a Hilbert filling curve. To keep image privacy, segments are transformed into an encrypted image by using random permutation. The encrypted image does not reveal significant information about the original one. Data embedment can be realized by using pixel histogram-style hiding, since this property, can be preserved before or after encryption. The proposed method is a modular method to compile some specific reversible data hiding to those in encrypted image with content owner privacy. Finally, our experimental results show that the image quality is 50.85dB when the averaged payload is 0.12bpp.

• 문화기술의 융합
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• 제7권1호
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• pp.632-639
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• 2021

본 논문에서는 기밀데이터를 암호화한 후, 암호화된 기밀데이터를 공간적으로 암호화하여 커버 이미지에 은닉하여 기밀데이터의 보안성을 크게 강화한 가역 데이터 은닉기법을 제안하였다. 암호화된 기밀데이터를 공간적인 암호화 기법으로 커버 이미지에 은닉하여 결과 이미지를 생성하면, 결과 이미지의 화질이 매우 우수하여 원본 커버 이미지와 결과 이미지를 시각적으로 구분할 수 없다. 암호화된 기밀데이터가 공간적으로 암호화되어 은닉되었기 때문에, 결과 영상의 어느 위치에 암호화된 기밀데이터가 은닉되어 있는지를 알 수 없어 결과 영상으로부터 암호화된 기밀데이터를 추출할 수 없다. 암호화된 기밀데이터를 추출하여도 기밀데이터가 암호화되어 있어서 원본 기밀데이터를 알 수 없게 된다. 따라서 제안기법을 사용하여 기밀데이터를 영상에 은닉하면 기밀데이터의 보안성이 크게 향상된다. 제안된 기법은 의료, 군사 등의 응용 분야에 효과적으로 사용될 수 있다.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2001년도 춘계학술대회논문집:21세기 신지식정보의 창출
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• pp.64-76
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• 2001

In this paper, A simple image hologram encryption and decryption technique based on the principle of interference are proposed. The technique using the photorefractive material for getting a stable interference pattern is also proposed. And combine these two techniques, I would like to implement a stable optical information security system. In the encrypting process, I would generate binary phase hologram which can reconstruct original image perfectly, and regard this hologram as original image to be encrypted image. And then the hologram is encrypted as randomly generated binary phase image. Reference image is also generated from the encrypted image by applying interference rule. In the decrypting process, I can get a interference intensity by interfering the reference image and the encrypted image in the interferometer. and transform inferference intensity information into phase information. I recover original image by inverse Fourier transforming the phase information. In this process, the intensity information generated by interference of two images is very sensitive to external vibrations. So, I would like to get a stable interference using the characteristic of SPPCM(self pumped phase conjugate mirror) in photorefractive materials, especially BaTiO₃.

• Journal of the Optical Society of Korea
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• 제19권3호
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• pp.241-247
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• 2015

The double-random phase encryption (DRPE) algorithm is a robust technique for image encryption, due to its high speed and encoding a primary image to stationary white noise. Recently it was reported that DRPE in the Fresnel domain can achieve a better avalanche effect than that in Fourier domain, which means DRPE in the Fresnel domain is much safer, to some extent. Consequently, a method based on DRPE in the Fresnel domain would be a good choice. In this paper we present an image-authentication method which uses only partial phase information from a double-random-phase-encrypted image in the Fresnel domain. In this method, only part of the phase information of an image encrypted with DRPE in the Fresnel domain needs to be kept, while other information like amplitude values can be eliminated. Then, with the correct phase keys (we do not consider wavelength and distance as keys here) and a nonlinear correlation algorithm, the encrypted image can be authenticated. Experimental results demonstrate that the encrypted images can be successfully authenticated with this partial phase plus nonlinear correlation technique.

• 한국멀티미디어학회논문지
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• 제7권3호
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• pp.349-356
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• 2004

본 논문에서는 SA(simulated annealing) 알고리듬에 기반한 4-f 광 상관 시스템을 이용하여 실제적인 영상 보안 시스템을 제안하였다. 반복적인 SA알고리듬을 이용하여 이진 위상 성분을 갖는 암호화된 영상과 키 영상을 얻고, 4-f 광 상관 시스템을 이용하여 암호화된 영상과 키 영상과의 상관을 통해 복호화된 영상이 구해진다. 제안된 방법에서는 암호화된 영상 및 키 영상이 이진 위상 성분으로 구성되므로 광 보안 시스템을 구현하기 쉬운 장점이 있다. 그리고 만약 암호화된 영상을 암호화 시스템내에서 고정시키고, 키 영상 정보만을 달리 하면 서로 다른 영상을 복호화할 수 있으므로 차별화된 인증시스템에 응용할 수 있는 장점도 있다. 컴퓨터 시뮬레이션 결과는 두 영상(암호화 및 키 영상)의 이진 위상 성분에도 불구하고, 복호화영상이 생성됨을 보여준다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.958-961
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• 1999

A new image encoding and identification scheme is proposed for security verification by using CGH(computer generated hologram), random phase mask, and correlation technique. The encrypted image, which is attached to the security product, is made by multiplying QPH(quadratic phase hologram) using SA(simulated annealing) algorithm with a random phase function. The random phase function plays a role of key when the encrypted image is decrypted. The encrypted image could be optically recovered by 2-f system and automatically verified for personal identification. Simulation results show the proposed method cand be used for the reconstruction and the recognition of the encrypted. Image.

• Journal of the Optical Society of Korea
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• 제4권1호
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• pp.19-22
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• 2000

A new image encoding and identification scheme is proposed for security verification by us-ing a CGH(computer generated hologram), random phase mask, and a correlation technique. The encrypted image, which is attached to the security product, is made by multiplying a QP- CGH(quadratic phase CGI) with a random phase function. The random phase function plays a key role when the encrypted image is decrypted. The encrypted image can be optically recovered by a 2-f imaging system and automatically verified for personal identification by a 4-f correlation system. Simulation results show the proposed method can be used for both the reconstruction of an original image and the recognition of an encrypted image.

• 대한전자공학회논문지SD
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• 제40권9호
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• pp.658-665
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• 2003

본 논문에서는 위상 변조된 가상 영상을 이용하여 암호화 수준을 향상시키고 퓨리에 영역에서 잡음이나 변이에 강한 복호화 방법을 제안하였다. 암호화된 영상은 원 영상이 아닌 위상 변조된 가상 영상과 무작위 위상 영상을 곱하여 퓨리에 변환하여 만든다. 따라서 허가되지 않은 사용자가 암호화된 영상을 분석함으로써 있을 수 있는 복제 가능성을 원 영상의 어떤 정보도 포함하지 않은 가상 영상을 사용함으로써 배제할 수 있다. 복호화 과정은 암호화된 영상과 제안한 위상 대응 규칙으로 만들어진 퓨리에 복호화 키를 간섭시킨 후 퓨리에 역변환하여 간단히 원 영상을 재생하고 컴퓨터 모의 실험을 통하여 제안한 방법의 암호화된 영상과 복호화 키 영상에 잡음이나 영상의 절단, 변이가 발생하더라도 원 영상의 복원이 가능함을 확인하였다.

• Journal of Information Processing Systems
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• 제9권3호
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• pp.499-510
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• 2013

Hardware-Software co-simulation of a multiple image encryption technique shall be described in this paper. Our proposed multiple image encryption technique is based on the Latin Square Image Cipher (LSIC). First, a carrier image that is based on the Latin Square is generated by using 256-bits of length key. The XOR operation is applied between an input image and the Latin Square Image to generate an encrypted image. Then, the XOR operation is applied between the encrypted image and the second input image to encrypt the second image. This process is continues until the nth input image is encrypted. We achieved hardware co-simulation of the proposed multiple image encryption technique by using the Xilinx System Generator (XSG). This encryption technique is modeled using Simulink and XSG Block set and synthesized onto Virtex 2 pro FPGA device. We validated our proposed technique by using the hardware software co-simulation method.