• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.864-867
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• 2005

All-optical networks are emerging as a promising technology for per second class communication. However, they are intrinsically different from electro-optical networks, particularly because they do not regenerate signals in the networks. The characteristics of all-optical network components and architectures manifest and still unstudied security vulnerabilities but also offer a new array of possible countermeasures. In this paper, we have analysed the security issue to protect against intrusion.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.631-634
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• 2002

In this paper, we propose an improved optical security system using three phase-encoded images and the principle of interference. This optical system based on a Mach-Zehnder interferometer consists of one phase-encoded virtual image to be encrypted and two phase-encoded images, encrypting image and decrypting image, where every pixel in the three images has a phase value of '0' and '$\pi$'. The proposed encryption is performed by the multiplication of an encrypting image and a phase-encoded virtual image which dose not contain any information from the decrypted image. Therefore, even if the unauthorized users steal and analyze the encrypted image, they cannot reconstruct the required image. This virtual image protects the original image from counterfeiting and unauthorized access.. The decryption of the original image is simply performed by interfering between a reference wave and a direct pixel-to-pixel mapping image of the encrypted image with a decrypting image. Both computer simulations and optical experiments confirmed the effectiveness of the proposed optical technique for optical security applications.

• Current Optics and Photonics
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• v.8 no.3
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• pp.270-281
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• 2024

Information-hiding technology is introduced into an optical ghost imaging encryption scheme, which can greatly improve the security of the encryption scheme. However, in the current mainstream research on camouflage ghost imaging encryption, information hiding techniques such as digital watermarking can only hide 1/4 resolution information of a cover image, and most secret images are simple binary images. In this paper, we propose an equal-resolution image-hiding encryption scheme based on deep learning and computational ghost imaging. With the equal-resolution image steganography network based on deep learning (ERIS-Net), we can realize the hiding and extraction of equal-resolution natural images and increase the amount of encrypted information from 25% to 100% when transmitting the same size of secret data. To the best of our knowledge, this paper combines image steganography based on deep learning with optical ghost imaging encryption method for the first time. With deep learning experiments and simulation, the feasibility, security, robustness, and high encryption capacity of this scheme are verified, and a new idea for optical ghost imaging encryption is proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.760-763
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• 2004

We propose a biometrical information security method based on Optical Visual Cryptography in that a fingerprint data is processed by Secret Sharing method taking into account the Optical Visual Cryptography and a part of shared data transmitted through an open network. Whenever necessary the owner or the fingerprint can be authenticated by submitting his fingerprint with the other shared information.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.3
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• pp.63-69
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• 2001

Smartcard is highlighted as infrastructure that has an excellent security for executing functions such as user authentication, access control, information storage and control, and its market is expanding rapidly. But possibilities of forgery and alteration by hacking are increasing as well. This paper proposes a method to prevent card forgery and alteration using angular multiplexing and private key multiplexing method on optical encryption, and proposed a Public Key Infrastructure(PKI)-based authentication system combined with One-Time Password (OTP) for verification of forgery and alteration .

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.383-391
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• 2003

A new optical security system for the protection of personal identification information is proposed. Personal identification information consisting of a pure face image and an identification number is used for verification and authentication. Image encryption is performed by a fully phase image encryption technique with two random phase masks located in the input and the Fourier plane of 4-f correlator. The personal information, however, can be leaked out in the decryption process. To cope with this possibility, the encrypted image itself is used in the identification process. An encrypted personal identification number is discriminated and recognized by using the proposed MMACE_p (multiplexed MACE_p) filter, and then authenticity of the personal information is verified by correlation of the face image using the optical wavelet matched filter (OWMF). MMACE_p filter is a synthetic filter with four MACE_p (minimum average correlation energy_phase encrypted) filters multiplexed in one filter plane to recognize 10 different encrypted-numbers at a time. OWMF can improve discrimination capability and SNR (signal to noise ratio). Computer simulations confirmed that the proposed security technique can be applied to the protection of personal identification information.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.153-159
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• 2018

In this paper, we present a three-dimensional (3D) optical encryption technique for quick response (QR) code using computational synthesized integral imaging, computational volumetric reconstruction, and double random phase encryption. Two-dimensional (2D) QR code has many advantages, such as enormous storage capacity and high reading speed. However, it does not protect primary information. Therefore, we present 3D optical encryption of QR code using double random phase encryption (DRPE) and an integral imaging technique for security enhancement. We divide 2D QR code into four parts with different depths. Then, 2D elemental images for each part of 2D QR code are generated by computer synthesized integral imaging. Generated 2D elemental images are encrypted using DRPE, and our method increases the level of security. To validate our method, we report simulations of 3D optical encryption of QR code. In addition, we calculated the peak side-lobe ratio (PSR) for performance evaluation.

• Current Optics and Photonics
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• v.7 no.4
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• pp.362-377
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• 2023

Optical information processing technology is characterized by high speed and parallelism, and the light features short wavelength and large information capacity; At the same time, it has various attributes including amplitude, phase, wavelength and polarization, and is a carrier of multi-dimensional information. Therefore, optical encryption is of great significance in the field of information security transmission, and is widely used in the field of image encryption. For multi-image encryption, this paper proposes a multi-image encryption algorithm based on a modified Gerchberg-Saxton algorithm (MGSA) in the Fresnel-transform domain and computational ghost imaging. First, MGSA is used to realize "one code, one key"; Second, phase function superposition and normalization are used to reduce the amount of ciphertext transmission; Finally, computational ghost imaging is used to improve the security of the whole encryption system. This method can encrypt multiple images simultaneously with high efficiency, simple calculation, safety and reliability, and less data transmission. The encryption effect of the method is evaluated by using correlation coefficient and structural similarity, and the effectiveness and security of the method are verified by simulation experiments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.4
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• pp.37-48
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• 1999

Current encryption methods have been applied to secure communication using discrete chaotic system whose output is a noise-like signal which differs from the conventional encryption methods that employ algebra and number theory[1-2] We propose an optical encryption method that transforms the primary pattern into the image pattern of discrete chaotic function first a primary pattern is encoded using permutation algorithm, In the proposed system we suggest the permutation algorithm using the output of key steam generator and its security level is analyzed. In this paper we worked out problem of the application about few discrete chaos function through a permutation algorithm and enhanced the security level. Experimental results with image signal demonstrate the proper of the implemented optical encryption system.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.