Color image encryption using vectorial light field through a compact optical set-up

Abstract

Vector light fields have spatially non-uniform polarization across the transverse plane. In this study, a color image encryption scheme has been proposed in which the data is encoded into the spatially varying polarization states of light to achieve higher degrees of freedom. This scheme provides a strong security and a straightforward way for optical implementation. Simulation and experimental results have been presented to verify the feasibility of the proposed scheme.

Image encryption using binary polarization states of light beam

“…Here, the gray values from 0 to 255 are equivalent to phase values − π to π . The mathematical expression of the intensity distribution, I ( x , y ) of the encoded light beam after passing through an analyzer having transmission axis at an angle θ from the x -axis, can be expressed as 40 , where < … > denotes the time average. The intensity distribution, I ( Ω,θ ) at any point ( x , y ) depends on both the analyzer angle θ and the gray level Ω ( x , y ) corresponding to that point.…”

“…Perfect pixel-to-pixel matching is difficult to achieve, otherwise, it introduces errors in the decoded data. Recently, spatially variable polarization image encryption techniques using single SLM has been reported which make practical implementation simpler but numerous intensity measurements for Stoke’s polarimetry calculation are still necessary, create difficulties for instant application 20 , 40 . These techniques used single random dataset as the encryption key, thus there is a scope for further enhancement of security by using additional keys.…”

Asymmetric multi-image encoding and hiding scheme with structured fingerprint phase masks using gyrator transform and phase-shifting digital holography

“…Different types of phase masks, such as fingerprint phase mask, chaotic phase mask, structured phase mask, voice key, and chaotic fingerprint phase mask have been reported in the literature, which make the tasks of the attackers difficult [18][19][20][21][22]. DNA encoding, interference, vector beam, ghost imaging, wavelength multiplexing, and polarizationbased encryption schemes have also been reported in the literature [23][24][25][26][27][28][29][30][31][32][33].…”