Fast and Lightweight Hybrid Image Encryption and Steganography Leveraging an SPN, Chaotic Maps, and LSB Substitution

The rapid growth of digital communication has heightened the need for the secure transfer of sensitive image data. This is due to the increasing threats posed by cyberattacks and unauthorized access. Traditional encryption methods, while effective for text and binary data, often face significant challenges when applied to images, due to their larger size and complex structure. These characteristics make it difficult to provide a robust security solution. In this paper, we present a fast and efficient hybrid image encryption and steganography algorithm that leverages a substitution–permutation network (SPN), a chaotic logistic map (CLM), and least-significant-bit (LSB) substitution. This approach aims to improve data security and confidentiality while maintaining low computational complexity. The chaotic map generates random sequences for substitution and permutation, ensuring high unpredictability. The SPN framework improves the confusion and diffusion properties of the encryption process. The LSB substitution method hides the encrypted data values within the pixels of the cover image. We evaluate the security and efficiency of the proposed algorithm using various statistical tests, including measurement of the mean square error (MSE) and peak signal-to-noise ratio (PSNR) and pixel difference histogram (PDH) analysis. The results indicate that our algorithm outperforms many existing methods in terms of speed and efficiency, making it suitable for real-time hybrid encryption and steganography applications.