Asymmetric Cryptosystem Using Improved Equal Modulus Decomposition in Cylindrical Diffraction Domain

We present a simple and efficient asymmetric cryptosystem using an improved equal modulus decomposition (EMD) in the cylindrical diffraction domain. Being different from a cryptosystem based on the conventional EMD, whose outputs are complex-valued, in the planer diffraction domain, our proposed cryptosystem uses the improved EMD and the cylindrical diffraction. Therefore, the proposed system achieves high robustness against the special attack based on iterative retrieval algorithms. Moreover, it has a merit of real-valued outputs due to the improved EMD. In addition, our proposed asymmetric cryptosystem achieves comparative advantages on encryption time, optical decryption complexity, and the data amount of storage or transmission when it is compared with the conventional EMD-based cryptosystems. The simulation results verify the validity of the proposed system.