With the fast evolution of digital data exchange, security information becomes much important in data storage and transmission. Due to the increasing use of images in industrial-process, it is essential to protect the confidential image data from unauthorized access. In this paper, the authors analyze the Advanced Encryption Standard (AES), and they add a key stream generator (A5/1, W7) to AES to ensure improving the encryption performance; mainly for images characterised by reduced entropy. Comparative study with traditional encryption algorithms is shown the superiority of the modified algorithm. Detailed results in terms of security analysis and implementation are given. Comparative study with traditional encryption algorithms is shown the superiority of the modified algorithm.