The Experts below are selected from a list of 3909 Experts worldwide ranked by ideXlab platform

Kehar Singh - One of the best experts on this subject based on the ideXlab platform.

  • phase image encryption in the fractional hartley domain using arnold transform and singular value decomposition
    Optics and Lasers in Engineering, 2017
    Co-Authors: Phool Singh, Anil Kumar Yadav, Kehar Singh
    Abstract:

    Abstract A novel scheme for image encryption of phase images is proposed, using fractional Hartley transform followed by Arnold transform and singular value decomposition in the frequency domain. Since the plaintext is a phase image, the Mask used in the spatial domain is a random Amplitude Mask. The proposed scheme has been validated for grayscale images and is sensitive to the encryption parameters such as the order of the Arnold transform and the fractional orders of the Hartley transform. We have also evaluated the scheme's resistance to the well-known noise and occlusion attacks.

  • vulnerability of the security enhanced double random phase Amplitude encryption scheme to point spread function attack
    Optics and Lasers in Engineering, 2012
    Co-Authors: Pramod Kumar, Joby Joseph, Arvind Kumar, Kehar Singh
    Abstract:

    Abstract: The security enhanced double random phase-Amplitude encryption (DRPAE) scheme which has been shown to be resistant to the known plaintext attack, is found susceptible to a simple point spread function (PSF) attack, as in case of the DRPE. Analogy of the DRPAE scheme with the 4-f imaging system is utilized to search for the required PSF, and an a priori knowledge of the Amplitude Mask is not required. Numerical simulations validate the efficacy of our proposed attack. Existence of the linearity in the DRPAE scheme is also examined.

  • known plaintext attack free double random phase Amplitude optical encryption vulnerability to impulse function attack
    Journal of Optics, 2012
    Co-Authors: Pramod Kumar, Joby Joseph, Kehar Singh
    Abstract:

    A security enhanced double random phase-Amplitude encryption (DRPAE) scheme is immune against the powerful known-plaintext attack, due to the insertion of an undercover Amplitude random Mask at the Fourier plane in the conventional double random phase encryption (DRPE) scheme. However, DRPAE, which nullifies the high level known-plaintext attack, is found to be susceptible to a simple impulse function attack. Information about the exact distribution of the Amplitude Mask as well as that of the Fourier plane random phase Mask is divulged from an impulse function attack. A variant form of the impulse function attack is also able to show that the DRPAE scheme is as linear as the conventional DRPE scheme. Numerical simulation results validate the effectiveness of the simple impulse attack on the DRPAE scheme.

Xiaogang Wang - One of the best experts on this subject based on the ideXlab platform.

  • optical double binary Amplitude Mask structure for security authentication
    IEEE Photonics Journal, 2016
    Co-Authors: Xiaogang Wang, Guoquan Zhou
    Abstract:

    A novel method for jointly designing two binary Amplitude Masks (BAMs) that allow for secure authentication is proposed. The speckle-noise diffraction pattern generated numerically from the input secret image encrypted by a random phase is binarized and further compressed. The resulting BAM can be separated into two desired BAMs, each of which does not visually render the primary information when applied for verification. Simulation results are presented to verify the validity and effectiveness of the proposed method.

  • double image encryption without information disclosure using phase truncation fourier transforms and a random Amplitude Mask
    Applied Optics, 2014
    Co-Authors: Xiaogang Wang, Daomu Zhao, Yixiang Chen
    Abstract:

    We present a study about information disclosure in phase-truncation-based cryptosystems. The main information of the original image to be encoded can be obtained by using a decryption key in the worst case. The problem cannot be thoroughly solved by imaginary part truncating, keeping the encryption keys as private keys, or applying different phase keys for different plaintexts during each encryption process as well as the phase modulation in the frequency domain. In order to eliminate the risk of unintended information disclosure, we further propose a nonlinear spatial and spectral encoding technique using a random Amplitude Mask (RAM). The encryption process involving two security layers can be fully controlled by a RAM. The spatial encoding of the plaintext images and the simultaneous encryption of the plaintext images and the encryption key greatly enhance the security of system, avoiding several attacks that have cracked the phase-truncation-based cryptosystems. Besides, the hybrid encryption system retains the advantage of a trap door one-way function of phase truncation. Numerical results have demonstrated the feasibility and effectiveness of the proposed encryption algorithm.

  • Amplitude phase retrieval attack free cryptosystem based on direct attack to phase truncated fourier transform based encryption using a random Amplitude Mask
    Optics Letters, 2013
    Co-Authors: Xiaogang Wang, Daomu Zhao
    Abstract:

    We propose a simple Amplitude-phase retrieval attack free cryptosystem based on direct attack to phase-truncated Fourier-transform-based encryption using a random Amplitude Mask (RAM). The RAM that is not saved during the encryption provides extremely high security for the two private keys, and no iterative calculations are involved in the nonlinear encryption process. Lack of enough constraints makes the specific attack based on iterative Amplitude-phase retrieval algorithms unusable. Numerical simulation results are given for testing the validity and security of the proposed approach.

Yuanmei Gao - One of the best experts on this subject based on the ideXlab platform.

  • observation of the modulation instability induced by both intrinsic noise and the Amplitude Mask with periodic lattices
    Optik, 2015
    Co-Authors: Rong Lin, Yuanmei Gao
    Abstract:

    Abstract We observe experimentally two types of modulation instabilities induced by both intrinsic noise and the Amplitude Mask with periodic photonic lattices in self-defocusing media LiNbO 3 : Fe crystal. We find the participation of the Amplitude Mask accelerates the appearance of the modulation instability. Besides, we observe the modulation instability in two situations when the Amplitude Mask with periodic photonic lattices is used. One is when the angle between the principle axis of the periodic lattices and c axis of the crystal is 0°, and another is 45°. We find periodic photonic lattices have a strong suppression to the further development of the modulation instability in the latter situation.

  • optically induced two dimensional photonic quasicrystal lattices in iron doped lithium niobate crystal with an Amplitude Mask
    Applied Physics Letters, 2012
    Co-Authors: Wentao Jin, Yuanmei Gao
    Abstract:

    We fabricate two-dimensional photonic quasicrystal lattices in iron-doped lithium niobate photorefractive crystal by a single Amplitude Mask. The experimental setup of this method is very simple and flexible without complicated optical adjustment system. It can be applied in almost any optical laboratories. We analyze the photonic quasicrystal lattices by plane wave guiding, Brillouin-zone spectroscopy and far field diffraction pattern imaging. The induced photonic quasicrystal lattices can exist stably for a long time in the photorefractive crystal. This method can be easily extended to generate more complex quasi-periodicity microstructures by designing the Amplitude Mask properly.

  • optical fabrication of three dimensional photonic lattices in linbo3 fe crystals with a single Amplitude Mask
    Optics Communications, 2011
    Co-Authors: Wentao Jin, Yuanmei Gao
    Abstract:

    Abstract We fabricate three-dimensional nonlinear photonic lattices in iron-doped lithium niobate photorefractive crystal for the first time by a single Amplitude Mask. The experimental setup of this method is very simple and flexible. The period of the lattices can be dominated easily. We analyze the three-dimensional photonic lattices by plane wave guiding and far field diffraction pattern imaging. The induced photonic lattices can exist stably for a long time in the photorefractive crystal.

Xiang Peng - One of the best experts on this subject based on the ideXlab platform.

  • optical cryptosystem based on phase truncated fresnel diffraction and transport of intensity equation
    Optics Express, 2015
    Co-Authors: Chenggong Zhang, Xiang Peng
    Abstract:

    A novel optical cryptosystem based on phase-truncated Fresnel diffraction (PTFD) and transport of intensity equation (TIE) is proposed. By using the phase truncation technique, a phase-encoded plaintext could be encrypted into a real-valued noise-like intensity distribution by employing a random Amplitude Mask (RAM) and a random phase Mask (RPM), which are regarded as two secret keys. For decryption, a generalized Amplitude-phase retrieval (GAPR) algorithm combined with the TIE method are proposed to recover the plaintext with the help of two keys. Different from the current phase-truncated-based optical cryptosystems which need record the truncated phase as decryption keys, our scheme do not need the truncated phase because of the introducing of the TIE method. Moreover, the proposed scheme is expected to against existing attacks. A set of numerical simulation results show the feasibility and security of the proposed method.

Daomu Zhao - One of the best experts on this subject based on the ideXlab platform.

  • double image encryption without information disclosure using phase truncation fourier transforms and a random Amplitude Mask
    Applied Optics, 2014
    Co-Authors: Xiaogang Wang, Daomu Zhao, Yixiang Chen
    Abstract:

    We present a study about information disclosure in phase-truncation-based cryptosystems. The main information of the original image to be encoded can be obtained by using a decryption key in the worst case. The problem cannot be thoroughly solved by imaginary part truncating, keeping the encryption keys as private keys, or applying different phase keys for different plaintexts during each encryption process as well as the phase modulation in the frequency domain. In order to eliminate the risk of unintended information disclosure, we further propose a nonlinear spatial and spectral encoding technique using a random Amplitude Mask (RAM). The encryption process involving two security layers can be fully controlled by a RAM. The spatial encoding of the plaintext images and the simultaneous encryption of the plaintext images and the encryption key greatly enhance the security of system, avoiding several attacks that have cracked the phase-truncation-based cryptosystems. Besides, the hybrid encryption system retains the advantage of a trap door one-way function of phase truncation. Numerical results have demonstrated the feasibility and effectiveness of the proposed encryption algorithm.

  • Amplitude phase retrieval attack free cryptosystem based on direct attack to phase truncated fourier transform based encryption using a random Amplitude Mask
    Optics Letters, 2013
    Co-Authors: Xiaogang Wang, Daomu Zhao
    Abstract:

    We propose a simple Amplitude-phase retrieval attack free cryptosystem based on direct attack to phase-truncated Fourier-transform-based encryption using a random Amplitude Mask (RAM). The RAM that is not saved during the encryption provides extremely high security for the two private keys, and no iterative calculations are involved in the nonlinear encryption process. Lack of enough constraints makes the specific attack based on iterative Amplitude-phase retrieval algorithms unusable. Numerical simulation results are given for testing the validity and security of the proposed approach.