离散分数阶随机变换与加权直方图交叉置乱的双图像加密算法

发布时间：2018-10-30 07:59

【摘要】：为了实现对两幅图像进行同步加密,降低传输负载并提高密文的抗明文攻击能力,提出了离散分数阶随机变换与加权像素混沌置乱的双图像加密算法。将2个分阶参数引入到Tent映射中,设计了新的Tent映射;根据明文像素值,构建加权像素直方图模型,联合位外部密钥,生成改进的Tent映射的初值;再利用初值对分数阶Tent映射进行迭代,输出2组随机序列,对2幅明文进行位置交叉混淆,获取2个置乱密文;基于DWT(discrete wavelet transform)技术,对2个置乱密文进行稀疏表示;根据混沌序列,定义随机循环矩阵,联合稀疏表示,获取2个置乱密文对应的测量矩阵。根据随机掩码与调制相位掩码,建立数据融合模型,将2个测量矩阵组合为复合矩阵;基于离散分数阶随机变换,对复合图像进行扩散,获取密文。测试数据显示:与已有的多图像加密方案相比,该算法的抗明文攻击能力与用户响应值更理想,密文的NPCR、UACI值分别达到了99.83%、34.57%。该算法具有较高的加密安全性,能够有效抵御网络中的外来攻击,确保图像安全传输。
[Abstract]:In order to realize synchronous encryption of two images, reduce the transmission load and improve the anti-plaintext attack ability of ciphertext, a double image encryption algorithm based on discrete fractional random transformation and weighted pixel chaos scrambling is proposed. Two order parameters are introduced into the Tent mapping, and a new Tent map is designed, the weighted pixel histogram model is constructed according to the plaintext pixel value, and the initial value of the improved Tent mapping is generated by combining the external key and the bitwise key. Then the fractional Tent map is iterated by initial value, two sets of random sequences are outputted, two pieces of plaintext are obfuscated, two scrambled ciphertext are obtained, and two scrambled ciphertext are represented sparsely based on DWT (discrete wavelet transform) technology. According to the chaotic sequence, the random cyclic matrix is defined and the sparse representation is combined to obtain two measurement matrices corresponding to the scrambled ciphertext. According to the random mask and modulation phase mask, the data fusion model is established, the two measurement matrices are combined into composite matrices, and the composite images are diffused to obtain ciphertext based on discrete fractional random transformation. The test data show that compared with the existing multi-image encryption scheme, the algorithm has better anti-plaintext attack ability and user response value, and the NPCR,UACI value of ciphertext reaches 99.83 and 34.57 respectively. This algorithm has high encryption security, can effectively resist the external attacks in the network, and ensure the secure transmission of images.
【作者单位】：吉林农业科技学院电气与信息工程学院;哈尔滨工业大学计算机科学与技术学院;长春工程学院电气与信息工程学院;
【基金】：国家自然科学基金(61075077) 吉林省科技支撑项目(20150203002SF) 吉林省教育厅自然科学研究项目(2014317)
【分类号】：TP309.7;TP391.41

【相似文献】