The Algorithm Of Images Steganalysis And Tamper Authentication

With the rapid development of communicationsignal process and network technology, Internet is changing the world. All kinds of information spread quickly in Internet. Many Stego-images that are used steganographic communication are coming forth. There are so many tampered images that people can not distinguish between right and wrong too. It is important to study on the images steganalysis and tamper authentication. The study on the algorithm of images steganalysis can prevent lawless messages spreading and improve the study on images steganography. The study on images tamper authentication can improve people's recognition capability.This dissertation discussed the bit plane'property of images. The LSB and Hypo_LSB are same in 0 and 1 distributing and other sides. A steganography and a steganalysis algorithm in Hypo_LSB of image are proposed. Experimental results show that the steganography algorithm is good for hiding information and the steganalysis algorithm is effective.The thesis summarizesχ2and RS steganalysis algorithm on the stego-images. The two kinds of methods can't analysis images that are used hiding information in frequency domain better. A novel image's steganalysis and its improved algorithms based on DCT coefficient distributing are presented. Experimental results show that the new steganalysis algorithms can analysis information that are hidden both in space and frequency domain better and more quickly than others.At last, the dissertation summarized the tampered image's authentication techniques based on digital watermarking and digital signature. These protective images need processed before communication. The definition and theorem about digital image's matching measure are presented. A novel tampered image's authentication algorithm based on image's matching measure is proposed. It has the advantage of simple and easy implementing.