Optical cryptosystems using structured light: principle, progress, and future prospects

Abstract In today’s technological landscape, safeguarding information during transmission and storage has become a critical concern. In last three decades, optical techniques for information security have emerged as a powerful alternative to conventional digital methods, offering notable benefits such as high processing speed, several degrees of freedom, the use of physical parameters as encryption keys, and multidimensional data handling capabilities. This study provides a comprehensive overview of optical cryptosystems employing structured light that means structuring the light’s intensity, phase, and state of polarization. It mainly focuses on encryption-decryption techniques that utilize the properties of optical vortices, orbital angular momentum holography, arbitrary vector beams. In addition, the advantages, limitations, and prospective future directions of these approaches have been discussed.