Successive encryption and transmission with phase-shifting digital holography

Abstract

We present a novel information or key encryption and transmission technique based on phase-shifting digital holography for a security system. Phase-shifting digital holography is used for recording phase and amplitude information on CCD device. 4-step phase-shifting is implemented by moving the PZT mirror with equidistant phase steps of π /2. The information and the key are converted to random phase patterns. Digital hologram in this method is Fourier transform hologram and quantized with 256 gray-level. The basic idea is that we reuse a 256 gray-level digital hologram to encrypt the information or the key with 4-step phase-shifting digital holography. The encrypted binary data/image in the form of digital hologram can be transmitted through communication network, and is reconstructed and decrypted digitally. The simulation shows that the proposed method gives good results for a successive encryption/transmission.

Experimental Study of Two-step Phase-shifting Digital Holography based on the Calculated Intensity of a Reference Wave

“…The major advantages of digital holography, easy and highly sensitive recording of holograms and quick reconstruction, have been realized by rapidly developing CCD and computer technologies. Digital holography has been applied to microscopy [3][4][5], interferometry [6][7], image encryption [8,9], and recognition of 3D objects [10,11], and so on.…”

QPSK Modulation Based Optical Image Cryptosystem Using Phase-shifting Digital Holography

“…A phase-shifting digital holographic technique that uses a charge-coupled device(CCD) camera for direct recording of a hologram has an advantage of real time digital information processing without using holographic recording media, and can record the full complex information. [7][8][9][10][11][12][13][14][15][16][17][18] Phase-shifting digital holography to reconstruct the amplitude and the phase of light is more accurate than off-axis holographic techniques which record digital holograms. The optical encryption and decryption with this phase-shifting digital holographic technique has been well achieved for binary bit data, but is not good for a gray-level optical image.…”

Dual Optical Encryption for Binary Data and Secret Key Using Phase-shifting Digital Holography

“…[13][14][15][16] Recently, we have presented some papers on the optical encryption using the phase-shifting digital holographic method. [17][18][19][20][21][22] In this paper, we propose a dual optical encryption method for binary image data and secret key based on 2-step phaseshifting digital holography for a cryptographic system, and show the performance of the proposed system for dual cryptography. The encrypted Fourier transform hologram is obtained by phase-shifting a digital holographic technique from an optical setup based on a Mach-Zehnder type interferometer, which is a 256 gray level quantized digital hologram recorded by CCD.…”