Image cryptosystem with image key using integral disproportion

Abstract

The subject matter of this article is the process of securing visual data through encryption. The goal of this study is to develop a new approach for image encryption and decryption using an image as a key, where security and performance are comparable or superior to alternatives. The tasks to be solved are as follows: developing a symmetric image cryptosystem for both greyscale and colored images in any format that can use an arbitrary image as a security key; adapting the capabilities of integral disproportionality for image encryption. The encryption method applies an integral disproportion formula for each pair of pixels’ components for both the input image and the key image starting from the first one. The output is a ciphered object represented as an array of real numbers, with decryption being the inverse process. The result is a novel approach to image encryption, proposing a new cryptosystem in which an arbitrary image of varying size, format, or content serves as the encryption key. The proposed symmetric full-encryption cryptosystem is applicable to both greyscale and colored images in any format. The method employs a frequency-based approach that influences the values of pixels rather than their positions. In contrast to mainstream approaches in this area, the representation of a cipher is not an image but a binary array. The proposed algorithm is simple to implement. The proposed method appears to meet the required requirements in both security and performance. Conclusions. The scientific novelty of the results obtained is as follows: This research introduces a new image encryption method, which is unique in its application of integral disproportionality to alter pixel values, differing from traditional encryption methods. This provides a practical yet secure option to the existing encryption techniques.