利用纠错码的JPEG图像压缩域隐写算法

在对JPEG图像压缩域数据进行分析的基础上,提出了一种以JPEG图像为载体的隐写算法.算法利用纠错码信息隐藏的原理,以对共享密钥进行纠错编码得到的纠错码码字为载体码字,将对秘密信息进行映射编码得到的错误图样嵌入其中,得到载密码字;然后以块为单位,将载密纠错码码字嵌入到JPEG图像压缩域中幅值较大的AC系数中.实验及分析表明,算法在确保一定的嵌入容量的情况下,具有较好的视觉不可感知性和统计不可感知性,并且满足密码学中的"Kerchhoff准则".

Steganography in JPEG Encoded Images Using Error-Correcting Code

According to the analysis of compressed data of JPEG encoded images,a secure steganographic algorithm for JPEG images is proposed.With this algorithm,a mapping relationship between secret bits and error map is built first and then the error map is embedded into the cover-codeword which is derived from error-correcting encoding to the shared key,and the stego-codeword can be obtained.Afterwards,on a block-by-block basis,the stego-codeword is embedded into the larger AC coefficients in the compressed domain.Experimental results show that the proposed algorithm has a good visual and statistical imperceptibility and can guarantee a considerable embedding capacity as well.Furthermore,the algorithm satisfies the "Kerchhoff" rule in cryptography.