适用于Android手机的像素异或图像分块加密算法

Image block encryption algorithm based on pixel xor for Android phone

为了克服Android手机上图像加密速度慢的缺点,提出了一种适用于Android手机的像素异或图像分块加密算法,该算法将密码学中经典的RC4算法应用于本文的加密算法中。首先,将原始图像分块,将改进的RC4算法运用到相邻的两个子块之间的运算上,从而改变像素值,最后,通过Logistic映射对图像置乱。实验结果表明,原始图像加密后的图像类似噪声,加密后的直方图变得更平滑,有足够大的密钥空间,对密钥有很高的敏感性,密文图像的随机性好,密文图像相邻像素之间相关性低,加密算法在Android手机上有更快的加密速度。

In order to overcome the slow speed of image encryption for android phone,an image block encryption algorithm based on pixel xor is proposed for the Android Phones.In this algorithm,the classic RC4 algorithm in cryptography is modified,and then applied to this paper’s encryption algorithm.Firstly,the original image is divided into blocks.Then,the improved RC4 algorithm is applied to the operation between the adjacent two sub-blocks, thereby changes the value of pixels.Finally,the image is scrambled by logistic map.Experimental results show that the image has a noise-like characteristic and a flat histogram after the original image is encrypted,and that the algorithm has an enough large key space,a very high sensitivity to the key and a fast speed of image encryption for android phone and the encrypted image has a good randomness and has a low correlation between two adjacent pixels.