A Comparative Study and FPGA Implementation of Rubik’s Cube-Inspired Image Encryption Techniques
S. Sharmila, Dhandapani Vaithiyanathan, Raghuvel Subramaniam Bhuvaneswaran · IETE Journal of Research · 2025
The rapid growth of multimedia applications necessitates lightweight and hardware-efficient image encryption techniques for secure communication and data protection. This study presents a comparative evaluation of six image encryption algorithms using MATLAB simulations on standard grayscale images, assessed through NPCR, UACI, entropy, SSIM, PSNR, correlation, chi-square, NIST SP 800-22 statistical tests, and key sensitivity analysis. The results show that while all methods provide strong encryption performance, the Modified Rubik’s Cube (MRC) algorithm consistently achieves near-ideal entropy, high NPCR and UACI values, low pixel correlation, and accurate image reconstruction after decryption. Furthermore, the Rubik’s Cube, Modified Rubik’s Cube, and Chaotic Maps with Circular Shifts algorithms were implemented using Verilog HDL and synthesized on FPGA devices with AMD Xilinx tools. The MRC implementation demonstrated reduced setup delay, balanced power utilization, and low total supply power, confirming its effectiveness for real-time, energy-efficient, and secure image encryption suitable for embedded, IoT, and portable multimedia systems.