一种图像置乱加密新算法.pdf

计 算 机 与 现 代 化 　2006 年第 2 期 J ISUANJ I 　YU 　XIANDAIHUA 总第 126 期 ( ) 文章编号 2006 一种图像置乱加密新算法 郏宣耀 ( 宁波大红鹰职业技术学院软件学院 ,浙江 宁波 　315175) 摘要 :提出了一种实用的数字图像置乱新算法。该算法利用线性同余模型产生伪随机序列以对图像进行空间置乱 ,采用 异或操作实现图像的灰度变换。该算法密钥可变 ,变化数较多 ,且灰度直方图改变 ,难以穷举破解。同时解密算法容易 求得 ,解密过程与加密周期无关 ,从而大大缩短了解密时间。实验结果表明 ,该算法具有较好的抗攻击和抗干扰能力 ,并 且易于实现 ,是一种理想的图像置乱方法。 关键词 : 图像置乱;线性同余 ;灰度变换 中图分类号:TP391. 41 　　　　文献标识码 :A A Ne w Algorithm for Digital Image Scrambling J IA Xuanyao ( School of Software Engineering , Ningbo Dahongying Vocational Technology College , Ningbo　315175 , China) Abstract :This paper presents a useful new algorithm of digital image scrambling. It achieves space chaos of an image with a pseudoran dom sequence generated by linear congruential method , and achieves gray chaos by XOR operation. This algorithm’s secret keys are dif ferent to each other , and they are in many types , and the histogram is also different to the original image’s histogram , so it’s difficult to crack the encrypted image by exhaustive method. On the other hand , the decryption method is easy to obtain , and the decryption process is irrelative with the encryption cycle , so it shortens the time consuming of decryption greatly. The results of experiment indicate that , this algorithm plays a good performance in antiattack and antijamming , and what ’s more , it ’s easy to be realized , so it is an ideal method for image scrambling. Key words :image scrambling ;linear congruential ;gray transforming 换[1 ] 、幻方变换[2 ] 、仿射变换[3 ] 、正交变换[4 ] 、Gray 变 0 　引　言