Image encryption based on Tetris puzzle game and a ring oscillator coupled with a Van der Pol oscillator

Abstract This paper proposes an image encryption scheme based on the logic of the Tetris game and a ring oscillator coupled with a Van der Pol oscillator. The proposed scheme relies on simultaneous permutation–diffusion mechanism, in which the permutation stage involves pixel extraction and recombination in patterns similar to Tetris tetrominoes. Both encryption phases exploit a chaotic sequence generated by the coupled oscillator system. Prior to encryption, the dynamics of the coupled oscillator system is studied thoroughly, extending beyond previous studies that were limited to bifurcation illustrations. Results of dynamical study reveal complex behaviors such as bifurcation, multistability, and chaos. The latter dynamic property is critical in the encryption process and leads to strong performance results, demonstrating the robustness of the proposed encryption scheme.