【摘要】 设计了一种基于Tent映射的混沌加密、隐藏算法。利用明文图像信息参数控制混沌密钥产生,增强混沌密钥与明文数据之间的联系。混沌映射的迭代使用高精度数据运算,避免了混沌系统迭代过程进入周期循环。利用混沌系统产生伪随机序列对图像的采样数据进行置乱操作,将获得的密文像素分成2部分嵌入到公开图像中,改变了密文外观特性。对加密后的图像进行像素变化率(Number of Changing Pixel Rate,NPCR)和归一化平均变化强度(Unified Averaged Changed Intensity,UACI)分析、相邻像素相关性分析、图像信息熵分析及加密运算速度分析发现:提出的加密算法具有较快的加密速度和良好的保密特性。更多还原

【Abstract】 An image encryption and hiding algorithm based on tent map is proposed. The algorithm adopts dynamic encryption keys which correlate with plaintext in order to resist known plaintext attack. The Pseudo-Chaotic sequence is operated by high-precision data to avoid finite computer precision effects on the period of chaotic system. The algorithm adopts two confusion steps as position scrambling and bits scrambling, in which the ciphertext is embedded into the cover image for changing its appearance. Several performance and security analysis of the encryption scheme is carried out, including Number of Changing Pixel Rate(NPCR), Unified Averaged Changed Intensity(UACI), and so on. The analysis result shows that the encryption algorithm has faster encryption speed and better confidentiality characteristics than those of prevailing methods.更多还原