A Hybrid Encryption Framework Combining Classical and Modern Techniques for Enhanced Image Encryption
Naresh Singh, Yashpal Singh, Sumit Sangwan, Bhupesh Kumar Singh · Indian Journal of Science and Technology · 2026
Background/Objectives: Digital images exhibit substantial spatial redundancy and strong correlation among neighboring pixels, making effective disruption of spatial and intensity characteristics, an important objective in image encryption. This study proposes a two-layer hybrid image-encryption architecture that integrates Rubik’s Cube-based spatial scrambling, AES-128 encryption, and Genetic Algorithm (GA)-based candidate-key selection. Method: The proposed architecture first applies Rubik’s Cube scrambling controlled by a chaotic logistic map sequence and subsequently performs AES-128 encryption using a candidate key selected via a GA. The GA utilizes a composite fitness function based on Shannon entropy, Number of Pixels Change Rate (NPCR), and Unified Average Changing Intensity (UACI). The reported configuration uses a population size of 100, a maximum of 200 generations, a crossover rate of 0.8, and a mutation rate of 0.01. The experimental evaluation considers 512 × 512 benchmark images and ten repeated runs using an Intel Core i7 processor with 16 GB RAM, Python 3.9, PyCrypto, and OpenCV. Findings: Across the four evaluated image labels, entropy ranges from 7.995 to 7.998, NPCR from 99.58% to 99.67%, and UACI from 33.28% to 33.89%. In a comparative evaluation, the proposed hybrid method achieves an entropy of 7.998, a correlation coefficient of 0.0015, NPCR of 99.67%, UACI of 33.5%, PSNR of 56.7 dB, and an encryption time of 12.4 ms. Novelty: The results indicate favorable outcomes across the assessed imageencryption metrics, suggesting that the integration of spatial scrambling, evolutionary candidate-key selection, and AES-128 forms an effective hybrid framework with a manageable computational cost. Keywords: Image encryption; Advanced Encryption Standard (AES); Rubik’s Cube scrambling; Genetic Algorithm; image security; chaotic map