经过置乱变换的水印再用混沌技术进行加密,在密钥未知的前提下,非授权者无法获取嵌入的数字水印,从而提高了水印系统的安全性-After scrambling transformation chaotic watermarking technology and then encrypted in the key premise of the unknown, unauthorized persons can not obtain the embedded watermark, so as to enhance the security of the watermarking system