中文摘要：

由于当前的Logistic混沌映射无法满足一致分布，且在混沌区域存在空白窗口，使得混沌区域较小，在利用该映射加密图像时，导致了较小的密钥空间，降低了加密系统的安全性。因此，定义了一个循环椭圆曲线，设计了一致分布Logistic混沌映射和伪随机混合密钥流生成器，再根据混沌方程与循环椭圆曲线，构造一个加密函数，提出了循环椭圆曲线与一致分布Logistic混沌映射相融合的图像加密算法。首先，根据一致分布Logistic混沌映射和256位的外部密钥以反馈模式生成初始密钥流；然后利用循环椭圆曲线产生的伪随机位序列混合初始密钥流，得到伪随机混合加密数据流；最后根据加密函数对图像进行加密。借助MATLAB仿真平台，对算法及其他几种加密系统进行了对比仿真分析。结果表明：与当前的Logistic映射相比，设计的混沌映射具有更好的一致分布行为；与其他几种加密算法相比，具有更好的加密质量；且密钥空间巨大。

英文摘要：

The small key space, small chaotic domain and low security were caused by the current logistic cha- otic map which not meeting the requirement of information distribution during the eneryption process and existing the bank window in the chaotic area. So, the cyclic elliptic curve was defined, and the uniform distribution logistic chaotic map as well as the pseudorandom mixed key-stream generator was designed. Meanwhile, the encryption function was constructed by the logistic chaotic map and the cyclic elliptic curve, and the linear feedback shift reg- ister was introduced to propose the image encryption algorithm based on the uniform distribution logistic chaotic map coupled the cyclic elliptic curve. Firstly, the initial key stream was produced by the chaotic system and an external secret key of 256-bit in a feedback manner; then the pseudorandom mixed data encryption stream was obtained by the key sequences produced by the pseudorandom bit sequences produced by cyclic elliptic curve mixing the initial key stream; finally, the image was encrypted by the encryption function. The algorithm was tests on the MATLAB platform, the results showed that compared with the current logistic chaotic map, the chaotic logistic map designed had better uniform distribution behavior; and compared with other encryption algorithm the algorithm has better encryption qualitv： in addition, the key space of this algorithm was huge.