Abstract: According to the characteristic of higher secrecy of high-dimension chaotic system，a new digital image encryption algorithm based on four-dimension chaotic system was proposed.The results and analysis demonstrate that the algorithm has good properties of encryption，a large space of keys，good statistical characteristics，strong anti-noise ability.It can resist for the exhaustion attack and count attack，even if the attacker knows chaotic system that is adopted and encryption algorithm，as long as not knowing the entire key，wanting deciphering the primitive image is also comparatively difficult.It shows that the proposed scheme is of high security.

Key words: four-dimension chaotic system, chaos, image encryption, confusion, diffusion

摘要： 根据高维混沌系统具有更高安全性的特点，提出一种基于四维混沌系统的数字图像加密算法。实验结果和分析表明，该算法加密效果良好，具有很强的明密文敏感性，密钥空间大，能够抵御统计攻击、穷举攻击，具有较强的抗干扰能力，即便是攻击者知道加密所采用的混沌系统和具体的加密算法，但只要不知道完整的密钥，想要解密出原始图像也是比较困难的。该算法具有较高的安全性。

关键词: 四维混沌系统, 混沌, 图像加密, 置乱, 替代