Chosen-plaintext attacks on image ciphers based on nonlinear dynamical systems

Recent advances in the fields of wireless communication networks and digital technologies has resulted in a significant increase in multimedia data sharing, especially digital images. Digital images often carry sensitive and personal information, so ensuring their security has become a critical concern. To address these challenges, the cryptography community has developed various encryption techniques, many of which rely on nonlinear dynamical systems and employ processes such as pixel permutation and diffusion to secure images. In this article, we have analyzed various security vulnerabilities in image encryption schemes available in literature that are based on pixel permutation and substitution. The study is divided into two main parts. First, we identify four types of image encryption schemes based on nonlinear dynamical systems and demonstrate their susceptibility to chosen-plaintext attacks. Secondly, we implement a substitution-permutation based image encryption scheme and show that it can be distinguished using a small number of chosen plaintext pairs in a distinguishability game. Furthermore, we prove that an attacker can recover the original plaintext by leveraging knowledge of a few chosen plaintext-ciphertext pairs, despite that the implemented scheme successfully passes all security evaluation tests proposed in the literature for assessing the cryptographic strength of image encryption schemes.