【摘要】 为解决当前图像加密算法采用独立的置乱与扩散操作,降低算法内联性,且忽略混沌序列生成存在的时延因素,使其难以抵御明文攻击等不足,提出一种内联时延混沌映射耦合Lorenz系统的图像加密算法。将时间延迟引入Logistic映射中,生成Arnold映射的初值;基于明文像素点,构造Arnold映射迭代次数计算模型;根据Arnold映射的迭代次数,建立其映射控制参数的计算函数,生成一组随机序列,利用位置集合,完成图像置乱;迭代超混沌Lorenz系统,生成4D序列组;引入密钥流,修正4D序列组;构造像素扩散机制,完成图像加密。实验结果表明,与当前加密结构相比,该算法拥有更高的保密性能与更强的密钥敏感性。更多还原

【Abstract】 Using current image encryption algorithm is difficult to resist plaintext attacks induced by independently scrambling and diffusion operating resulting in reducing the algorithm’s inline,also the existing time delay factor of the chaos sequence is ignored,so the image encryption algorithm based on inline time delay chaotic map coupled with Lorenz system was proposed.The initial value of Arnold map was generated by introducing the time delay into the Logistic map.The iteration number model of Arnold map was constructed based on the pixels of plaintext.The initial value of Arnold map was generated by introducing the time delay into the Logistic map and basing on iteration number.The calculation function of the mapping control parameters was established based on the initial value for iterating to produce the random sequence and the image was permutated by position set.The 4Dsequence group was generated by iterating the hyper-chaotic system.The pixel diffusion mechanism was constructed by the modified 4Dsequence group with key stream to finish image encryption.Experimental results show that this algorithm has better security performance and stronger key sensitivity compared with the existing encryption structures.更多还原