Asymmetric cryptosystem by using modular arithmetic operation based on double random phase encoding

We proposed a novel asymmetric cryptosystem based on double random phase encoding technique. The asymmetric architecture is realized through a one-way operation of truncating the imaginary parts of the Fourier Transforms as private keys. The modular arithmetic operation is implemented on the real part to generate a trapdoor for decryption. A real-valued encoded result is obtained by the proposed method. Two random phase masks and the parameters of the modular arithmetic operation are opened up to the public. Without the private keys, illegal users cannot retrieve the secret image. Numerical simulation results are carried out to demonstrate the validity and security of the proposed method.