针对像素位置置乱，为了削弱当前加密密文存在的周期性，提出了一种基于洗牌算法的二方向折叠扩散混沌系统加密方法。仿真实验表明，该算法不仅能够较好地抗差分攻击、统计特性分析，密钥敏感度强，还能有效抵抗密文攻击，而且密钥空间大，加密效果好。

Aiming at the scrambling of pixel position, in order to weaken the periodicity of encrypted ciphertext, a two-direction folding diffusion chaotic system encryption method based on shuffling algorithm is proposed. The simulation results show that the algorithm can not only resist differential attack, statistical analysis, strong key sensitivity, but also effectively resist ciphertext attack. Moreover, the key space is large and the encryption effect is good.