线性移位寄存器在图像加密中的应用

图像加密技术作为数字信息保护的一种有效手段，随着信息技术的发展，人们对其安全性的要求越来越高。讨论了关于线性移位寄存器（LFSR）在图像加密中的应用。本算法先采用LFSR算法产生伪混沌比特密钥流，将该密钥流作为随机值映射算法和加密算法的初始参数。随机值映射算法取其中较高位的密钥流，生成置乱序列用于图像像素的位置置乱。另一组密钥流作为加密序列可对图像的像素值进行加密。实验结果表明该方法运算速度快，通过随机值映射算法产生的伪随机置乱和加密序列具有很强的可操作性、保密性，而且截取伪混沌比特密钥流的位数也可作为密钥存在。

The Application in Image Encryption by Line Feedback Shift Register

For digital information protection, image encryption is an effective technology. As the development of information technology, people also need more and more security on image encryption. This thesis discussed the application in image encryption by line feedback shift register. At first the system generated the initial pseudo-chaos bit key stream by LSFR. The key stream becomed the initial parameter of the random value mapped scrambling algorithm and chaos encryption algorithm. Mapping the image with the mapped stream which was generated by the random value mapped scrambling algorithm with the higher digital key stream, then encrypted the image with the encrypted stream which was generated by another key stream. The result shows this system runs lastly. The pseudo-random mapped stream and pseudo-encrypted stream that were generated by the random value scrambling algorithm both had a strong operational, confidentiality. Also the chosen pseudo-chaos bit key stream can become the keywords.