The existed content authentication schemes based on digital watermark have some shortcomings. In order to solve the problems, a speech content authentication scheme based on high-capacity watermark embedding is proposed, and the high-capacity embedding method is discussed. Firstly, speech signal is framed and segmented, and the samples of each segment are scrambled. Secondly, DCT is performed on the scrambled signal, and low-frequency coefficients are selected as the watermark embedding domain. Lastly, frame number is mapped to a sequence of integers and embedded into the domain based on the embedding method. Theoretical analysis and experimental evaluation results show that the proposed algorithm is inaudible, robust to desynchronous attacks, enhances the embedding capacity, and improves the security of watermark system.
