Digital Audio Watermark Synchronization Attack The Problem Study

The digital media has become an important information resource along with the rapid development of digital technology and computer networks. Consequently a series of issues such as the information safety of digital media, intellectual property rights (IPR) protection and authentication become increasingly protrudent, which has become an urgent issue of digital world. As an effectively complementary means of traditional encrypt methods, digital watermarking is a new technology of copyright protection and authentication resources as well as integrity under the environment of open networks. In recent years, great emphasis has been attached and it has become a hot topic in the field of multi-media signal processing.Firstly, this paper introduces the development and some related concepts of digital watermarking, which elucidates the background and significance of the research. Secondly, some related concepts and characters and common problems and algorithms of audio watermarking are listed. Then, based on synchronic problem two audio watermarking algorithms are present. Synchronic digital audio watermarking algorithm based on mean quantization. In this algorithm, the audio signal is decomposed using wavelet basis. Low frequency coefficients are selected to embed synchronic signal and watermark using mean quantization method. The watermark can be extracted without the original audio signal. The algorithm is robust to many operations on digital audio signal, such as noise addition, lossy compression. Synchronization algorithm for dual channel audio watermark based on SVD feature extraction. According to signals of dual channel audio have strong similarity, this algorithm use the method of SVD feature extraction to fix on the watermark synchronic location. Then, the watermarking was embedded into. Experimental results show that the algorithm's robust performance for synchronic attacks had been improved highly.