Cryptanalysis of the integrated chaotic systems based image encryption algorithm

Chaotic image encryption has been favored by more and more researchers, various techniques and chaotic systems have been introduced. Although chaotic systems have many advantages in image encryption, imperfect algorithm designs would compromise the security of chaotic image encryption algorithms. With this in mind, we carefully investigate the ICS-IE (Integrated Chaotic Systems based Image Encryption) algorithm reported in the most recent research paper. In this paper, we firstly point out some issues found in the ICS-IE algorithm, and then improve it. Without changing the security of the original algorithm, we cryptanalyze the improved ICS-IE algorithm and propose a chosen plaintext attack algorithm. With the moduli used in the ICS-IE algorithm and the proposed attack algorithm, some tests are carried out. Test results show that our analysis of modulus is correct, and the proposed algorithm can recover the plain images completely without knowing any secure key related information. Finally, some suggestions on improving the security of the ICS-IE algorithm are presented.