Multiple-information security system using spherical wave and chaotic random phase mask encoding

Abstract

An asymmetric multiple-information cryptosystem based on spherical wave and chaotic random phase mask (CRPM) is proposed. In this security system, each secret color image is decomposed into R, G, and B channels and then independently phase-only encoded. The resulting channel is first illuminated by spherical wave and then modulated by CRPM to obtain an encoded channel. Similarly, each encoded channel of n secret images is obtained and then individually multiplied together to produce a corresponding encoded channel. The final encoded image R, G, and B channels of n secret images are digitally concatenated. The proposed method has mainly three advantages over reported methods. First, extremely sensitive and robust parameters of CRPM and spherical wave are exploited as decryption keys to enhance the security levels. Second, the different secret images are encrypted by different decryption keys, which cannot be accessed by unauthorized users. Moreover, fewer optical components are employed in the proposed scheme. The extracted secret images are free from crosstalk noise effects. The load of the key’s management and transmission is lightened by using CRPM. The encryption and decryption processes can be implemented by optoelectronic setup. Numerical simulation results show the viability and security of the proposed method.