Voice Security Authentication And Tamper Detection Technology Based On Digital Watermarking

Digital watermarking,as an effective method to protect information security,realize anti-counterfeiting traceability and copyright protection,is an important branch and research direction of information hiding technology.In this paper,we mainly study the security authentication and tamper detection of speech through digital watermarking technology.Nowadays,a variety of speech watermarking techniques have been developed.The embedding methods we mainly use in this paper are echohiding and Quantization Index Modulation(QIM).These two watermarking methods have the advantages of simple operation,good speech quality and wide application among many watermarking methods.However,there are some problems in the research of these watermarking methods,such as low embedding capacity and low security,and more and more speech tampering types pose a serious threat to speech signals.In order to solve these problems,it is difficult to simply improve the embedded method,so we need to combine with other existing technologies to improve the related performance.Aiming at the problems existing in the security authentication and tamper detection of the existing digital watermarking technology,this paper discusses the security authentication and tamper detection of speech respectively,and mainly completes the following work:(1)A more secure echo-hiding method based on modified Pseudo-Noise(PN)sequence and Robust Principal Component Analysis(RPCA)is proposed.The RPCA is used to decompose the original audio signal into low-rank and sparse parts and then a pair of opposite modified PN sequences is employed to embed watermarks into them.The modified PN sequence improves the robustness of watermark detection by providing additional correlation peaks.Meanwhile,benefit from the RPCA and the opposite PN sequences,the security of the proposed method can be further improved,since watermarks cannot be detected from the whole watermarked signal even if the PN sequence is known,which is an obvious improvement compared with the previous PN sequence based echo-hiding methods.In the watermark detection process,we make use of the low-rank and sparse characteristics of the watermarked signal and watermarks can be separately detected from the low-rank and sparse parts by using the same RPCA decomposition parameter.Based on this basic framework,we also propose a multi-bit embedding method to improve the embedding capacity of the proposed method,which can obtain a doubled embedding capacity compared with the previous PN based echo-hiding methods.The proposed method was evaluated with respect to inaudibility,security,and robustness.The experiment results verified the effectiveness of the proposed method.(2)A tamper detection method based on Line Spectral Frequencies(LSFs)and Discrete Wavelet Transform(DWT)is proposed.We use echo-hiding technology to embed the LSFs of the speech itself as tamper detection watermarks into the speech.At the same time,we use QIM to embed synchronization code in DWT domain.Tamper detection is carried out by echo,LSFs and synchronous code together.Experiments show that the proposed method not only satisfies certain speech quality and robustness,but also has better security and fragility.In addition,this method has good accuracy in the detection of tampering.