Cryptanalysis of S-box-only chaotic image ciphers against chosen plaintext attack

S-boxes have been widely used as a base of new encryption strategies. Recently, the utilization of S-box becomes popular in image ciphers as a main approach to performing substitution. Based on a general model of S-box-only image ciphers, this paper performs a cryptanalysis on the performance of these kinds of ciphers against chosen plaintext attack. The cryptanalytic findings have been concluded that not only S-box-only image ciphers are practically insecure against chosen plaintext attack, but also the computational complexity of the attack is only O(128L), where L is the total number of pixels with respect to the image. Moreover, a real S-box-only chaotic image cipher is tested as an example analysis to demonstrate our assertion. Finally, we give four corresponding improvement ideas that help to design a secure cryptosystem based on S-boxes.