Vol 22 No 2

Asian Journal of Physics Vol. 22, No. 2 (2013) 101-108

Optical Cryptanalysis – A survey

Wenqi He and Xiang Peng*

College of Optoelectronic Engineering, Key Laboratory of Optoelectronics Devices and Systems,
Education Ministry of China, Shenzhen University, Shenzhen 518060, China

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We review several attacks on the optical encryption schemes based on double random phase encoding (DRPE) and its various variants. All the attacks were taken under the Kerckhoffs' hypothesis in the domain of cryptanalysis. Before doing this, we also make a brief analysis on the key-space and theoretical security level of mentioned encryption schemes. Furthermore, the state-of-art of optical cryptanalysis is reviewed and commented. © Anita Publications. All rights reserved.

Keywords: Optical cryptanalysis, optical encryption, optical information security, double random phase encoding, phase retrieval.

Refs: 61

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Asian Journal of Physics Vol. 22, No. 2 (2013)109-116

Digital watermarking method based on fractional Fourier transform

Jun Lang and Zheng-guang Zhang

¹College of Information Science and Engineering Northeastern University Shen yang, 110004 China

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In this paper, we propose a novel blind digital watermarking algorithm based on the fractional Fourier transform (FRFT) which is a generalization of the ordinary Fourier transform, and its output has the mixed time and frequency components of the signal. The original image is transformed by the fractional Fourier transform, and then the FRFT coefficients are modified by the information of watermark. The experimental results demonstrate that different coefficients have different effects on the watermark. After making a series of attacking experiments on the watermarked image, a novel scheme that has good invisibility is proposed. It has strong robustness against different attacks such as noise, JPEG compression, and Gaussian low-pass filter. © Anita Publications. All rights reserved.

Keywords: Digital watermarking; fractional Fourier transform; robustness; invisibility.

Ref : 24

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Asian Journal of Physics Vol. 22, No. 2 (2013) 117-126

Security enhanced asymmetric cryptosystem in fresnel domain

Sudheesh K Rajput and Naveen K Nishchal*

Department of Physics, Indian Institute of Technology Patna, Patliputra, Patna-800 013, India

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We propose a novel asymmetric cryptosystem with enhanced security based on phase-truncation approach and using modified Gerchberg-Saxton (G-S) phase retrieval algorithm in Fresnel transform domain. The input image bonded with a random phase mask (RPM) is Fresnel transformed and the spectrum is amplitude-truncated and phase-truncated. The amplitude-truncated value serves as first decryption key. The phase-truncated value bonded with another RPM is Fresnel transformed and again amplitude-truncated and phase-truncated. This amplitude-truncated function serves as the second decryption key while the phase-truncated function is again bonded with a different RPM and is converted into a phase-only image using modified G-S algorithm. For decryption, this phase-only image is inverse Fresnel transformed and results a phase-truncated function in the output. Finally original image is obtained after using all the correct Fresnel parameters and generated decryption keys. To measure the effectiveness of the proposed methods, we calculated the mean square error and correlation coefficient between the original and the decrypted images. We present simulation results in the support of proposed method. © 2013 Anita Publications. All rights reserved.

Ref : 52

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Asian Journal of Physics Vol. 22, No. 2 (2013) 127-133

Dual-image encryption by using an affine transform and fractional Fourier transform

Zhengjun Liu,^1,2,3,* Qun Wu³, and Shutian Liu⁴

¹Department of Automatic Measurement and Control, Harbin Institute of Technology, Harbin, 150001, China

²State Key Laboratory of Transient Optics and Photonics, Chinese Academy of Sciences, Xi'an, 710119, China

³Department of Electronic Science and Technology, Harbin Institute of Technology, Harbin 150001, China

⁴Department of Physics, Harbin Institute of Technology, Harbin, 150001 China

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We present a kind of encryption method based on affine transform and fractional Fourier transform. An affine transform is defined for image encryption. Two original images are regarded as real part and imaginary part before encoding. The affine transform and fractional Fourier transform are employed for changing the pixel values of the secret images. The parameters in affine transform serve as main key. ©Anita Publications. All rights reserved.

Keywords: cryptography; chaotic mapping, double image encryption.

Ref : 23

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Asian Journal of Physics Vol. 22, No. 2 (2013) 135-152

Experimental double random phase encoding technique under a joint transforms correlator architecture

John Fredy Barrera,^1,* Myrian Tebaldi² and Roberto Torroba²

¹Grupo de Ópticay Fotónica, Instituto de Física, Universidad de Antioquia, A.A 1226, Medellín, Colombia

²Centro de Investigaciones Ópticas (CONICET La Plata-CIC) and UID OPTIMO, Facultad de Ingeniería, Universidad Nacional de La Plata,

P.O. Box 3 C.P 1897, La Plata, Argentina

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We present a review for updating the last contributions in the field of optical encoding techniques using a joint transform correlator architecture. We focus on the experimental aspects with special reference to both photorefractive and digital based applications. We describe the usual situation involved in developing the experimental set-ups when these techniques are used in multiplexing encrypted data. We address the solution to cross talk and overlapping issues associated with the multiplexing handling.© Anita Publications. All rights reserved.

OCIS codes: 000.0000, 999.9999.

Ref : 45

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Asian Journal of Physics Vol. 22, No. 2 (2013) 153-166

Color information security system using gyrator transform domain

Muhammad Rafiq Abuturab

Department of Physics, Maulana Azad College of Engineering and Technology, Patna 801113, India

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This paper reviews recent works in the area of optical color information security system based on gyrator transform specially the applications of GT with random-structured phase encoding (RSPE), random-radial Hilbert phase encoding (RHPE), and noise-free joint extended gyrator transform correlator (JEGTC). In these methods, the color image is decomposed into three channels, i.e. red, green and blue. The three independent channels can avoid the interference of crosstalks efficiently. The transformation angles of gyrator transform give additional keys for each channel, and thus offer a high level robustness against existing attacks. The proposed optical design is free from axial movement, which is an important issue in an optical system that requires axial movements. The encryption process can be realized with electro-optical hybrid system. The Numerical simulations are demonstrated to verify the flexibility and effectiveness of the proposed method.© Anita Publications. All rights reserved.

OCIS codes: 100.2000, 070.0070, 050.0050.

Ref : 42

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Asian Journal of Physics Vol. 22, No. 2 (2013) 167-174

Image hiding using joint transform correlator and modified Gerchberg-Saxton phase retrieval algorithm

Isha Mehra and Naveen K Nishchal*

Department of Physics, Indian Institute of Technology Patna, Patliputra, Patna-800 013, INDIA

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In this paper, a novel image hiding technique based on joint transform correlator (JTC) and modified Gerchberg-Saxton (G-S) phase retrieval algorithm is proposed. Here, the two images are considered; one is input image to be hidden and the other one is used as the key or host image. The key image is converted into a phase-only image using modified G-S phase retrieval algorithm. These two images are placed in the joint input plane of a JTC architecture, which is then Fourier transformed and its joint power spectrum is computed. As a result, in the output of the optical system, a noisy host image (watermarked image) is visible. Thus, the watermarked image acts like a cover image. For recovery of the hidden image, only the phase key, used as a reference object, is required. Without knowledge of this exact phase key, hidden image cannot be recovered. The proposed scheme not only hides the original input data but also gives the disguising appearance of the input image. Computer simulation results are presented in support of the proposed idea. © 2013 Anita Publications.

Ref : 36

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Asian Journal of Physics Vol. 22, No. 2 (2013) 175-220,A1-A20

Optical encryption and decryption for information security applications : A Resource Letter

Arvind Kumar¹, Madan Singh² and Kehar Singh³

¹Department of Physics, Indian Institute of Technology; DelhiNew Delhi - 110016, India

²Instruments Design, Development, and Facility Centre, Staff Road, Ambala - 133 00, India

³ITM University,Gurgaon, (Haryana), India

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In this resource letter, we present a bibliography of research papers in journals and conference proceedings, books, and book chapters etc on the subject of optical/opto-electronic encryption and decryption for information security applications Some publications may not be directly concerned with the subject but are relevant and useful and are therefore included Publications have been listed year- wise and alphabetically by the first author’s surname in a particular year While efforts have been made to make the list of references as complete as possible, there may be some omissions because the subject has grown very fast during the last eighteen years or so Therefore no claim is made as to the completeness of the list We hope that this resource letter would serve as a useful tool to the beginners as well as to active researchers in the field Suggestions for any additions and corrections to the list would be highly welcome© Anita Publications All rights reserved.© Anita Publications. All rights reserved.

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ASIAN JOURNAL OF PHYSICS