摘要
图像包含大量的机密信息,在当前网络中传输易被攻击者窃取,而现有的图像加密技术难以兼顾安全性与加密效率。对此,提出有限域余弦变换耦合密钥定位的图像加密算法。首先,将图像分割成多个子块;随后,利用有限域余弦变换处理图像子块,构造中间图像;引入外部密钥,确定中间图像块的位置,再次利用有限域余弦变换,扰乱图像像素,完成图像置乱;迭代Logistic映射,构造像素加密函数,完成扩散。仿真结果表明:与当前图像加密技术相比,该算法具有更高的安全性与加密效率,且该算法的信息熵值更大,能够有效抗击差分攻击。
Images contain a large number of confidential information and are easy to be stolen by the attackers in current network transmission. However existing image encryption technology is difficult to balance both the security and the encryption efficiency. So in this paper we propose an image encryption algorithm with key localisation coupling the finite domain cosine transform. First,we divide the image into multiple sub-blocks; Secondly,we process these image sub-blocks with finite domain cosine transform to construct intermediate image;Finally,we introduce the external key to determine the location of the intermediate image block,and use finite domain cosine transform once again to disturb the pixels of image to complete image scrambling. After that we iterate the Logistic mapping,construct the pixel encryption function,and complete the diffusion. Simulation results show that this algorithm has higher security and encryption efficiency compared with current image encryption techniques,and the information entropy of this algorithm is bigger and is able to fight against differential attacks.
出处
《计算机应用与软件》
CSCD
2016年第7期318-320,325,共4页
Computer Applications and Software
关键词
图像加密
密钥空间
有限域余弦变换
中间图像
外部密钥
Image encryption
Key space
Finite domain cosine transform
Intermediate image
External key
