A Novel Method for Image Encryption Using Time Signature-Dependent S-Boxes Based on Latin Squares and the Playfair System of Cryptography

This paper presents an image encryption algorithm by using time signature-dependent S-Boxes, which are based on Latin squares, the Playfair system of cryptography, and functions that are inspired by the behavior of a Japanese ladder. The encryption algorithm includes four stages: the construction of the S-Box, the generation of keys, image diffusion, and image permutation. The public key is generated from the grey-scale values of the plaintext image and the time signature, and secret key consists of the time signature and two functions from 𝔽_2^8 to 𝔽_2^8 . Permutation and diffusion stages of the encryption algorithm are based on a given S-Box. Moreover, a chaotic map is used in the permutation phase for an effective shuffling of pixel positions. The simulation results and security analyses show that the proposed encryption scheme is quite secure and it can resist various cyber attacks effectively.