关键词: 切延迟椭圆反射腔映射系统, 二值序列, 彩色图像, 图像置乱, 加密

Abstract: To improve the performance of Tangent-Delay Ellipse Reflecting Cavity map System (TD-ERCS) and achieve effective protection of color image information, the authors proposed an improved algorithm for the TD-ERCS chaotic sequences and a color image encryption algorithm which was based on this improved sequences. The four-dimensional chaotic real sequences and binary sequences which had ideal random performance were obtained by improving the TD-ERCS. The image, which was composed of the RGB component of the color image, was scrambled by using the improved TD-ERCS chaotic sequences with 8×8 blocks, and then the image was encrypted. The theoretical analysis and experimental results show that the performances of improved TD-ERCS sequences are better than original sequences; the color image encryption algorithm has larger space of key, better encryption effect, higher encryption efficiency, and it also has better security to statistical analysis and stronger ability against JPEG compressing attacks.

Key words: Tangent-Delay Ellipse Reflecting Cavity map System (TD-ERCS), binary sequence, color image, image scrambling, encryption