Reaserach On MP3 Audio Digital Watermarking Technology

With the development of the multimedia and Internet, the mass production and transmission of digital audio products has become very convenient. Meanwhile, with the mature of audio compression techniques, the digital music, such as MP3 (MPEG-1 Audio Layer 3), is widely applied to Digital Audio Broadcasting, Audio-on-Demand and Online Music Scales Systems, Which leads to the copyright protection and safety certification of the audio media and other issues. As the effective complement of traditional encryption, digital watermarking has become one of the research hotspots in the information security domain. For the copyright of digital audio, audio digital watermarking plays an important role. MP3 is the most popular audio format on the Internet, and the most serious copyright problem is against it. In this paper, the digital watermarking program for MP3's copyright protection has been studied.The thesis first gives a comprehensive summarization about the digital audio watermarking. Then, with the MP3 coding standard, through the studying of the MP3's compress and decompress theory and analyzing the file format of MP3, a watermarking technology based on MP3's compress domain has been studied. At last, this paper proposes two new audio digital watermarking methods for copyright protection, as follow:(1) A audio digital watermarking scheme, which combines the RSA encryption technology and modifying the scale factors, is proposed. First, the algorithm uses the encrypted information of legal user, who purchases MP3 music legally, as a watermark. Second, a pseudo-random number generator (PRNG) is used to identify the embedding position of scale factors, and finally watermark is embedded according to certain rules.(2) A watermark embedding program which is achieved by modifying the Huffman code value is presented. First, the watermark information is encrypted by RSA; then according to the pre-determined Huffman code table, all the corresponding Huffman code value is obtained from MP3 bit stream; the watermark embedding position is determined by PRNG and finally according to certain rules watermark is embedded.In this paper, the proposed algorithm gathers the Integrity verification and copyright protection in integral. In case of copyright disputes, through the copyright information provided by the legal owner of MP3 music, the watermark extraction system is used for authentication, to provide the legal basis. The experimental result demonstrates that, both of the proposed algorithms are less time-consuming than MP3Stego with lower computational complexity and take an excellent imperceptibility for different types of music. The watermark can be extracted without original audio. The proposed blind watermarking methods have good practical value.