In this paper, a novel chaotic image encryption scheme based on multiple chaotic systems, a 2D cat map and S-box, is proposed. The two stages of masking based on multiple PLCMs (m-PLCMs) are performed - once before and once after the substitution by S-Box. The proposed chaotic encryption scheme (CES) is less computationally intensive compared to AES, and is expected to provide the same level of security. The simulation and analysis results show that the chaotic signals are greatly sensitive to the key and the algorithm has a large space of keys. At the same time, the algorithm exhibits good encryption speed (less computations), and better security performance. © 2007 IEEE.