Double-phase image encryption using interference concept, devil’s fractional vortex Fresnel lens phase masks, and the gyrator transform

Abstract

This paper includes a security analysis based on interference, utilizing the gyrator transform (GT), structured phase masks (SPMs), and a phase key created by a devil’s fractional vortex Fresnel lens (DFVFL) in the middle plane. The DFVFL enhances the cryptosystem's key space. It is constructed by combining the devil’s cantor function, a fractional vortex, and a Fresnel zone plate. Experimentally, such masks are advantageous during decoding because they provide extra parameters. DFVFL are diffractive optical elements (DOEs), which enhances their security as they are extremely difficult to replicate. Additionally, these masks possess multiple keys that store properties within a single mask, enhancing the system’s security parameters. DFVFLs are also significant in generating spiraling waves that carry orbital angular momentum (OAM) and find applications in cryptography, quantum computing, bio-photonics, astronomy, and the design of vortex lens and phase mask systems. The sensitivity to encrypting keys, including the GT rotation angles has been studied. In addition, the performance of the scheme has also been evaluated in terms of RMSE, PSNR, SSIM, key space examination, key-sensitivity analysis, entropy, histogram, 3D mesh, correlation, and attacks involving contamination noise. The proposed technique resists various attacks and enhances security.