Multi-watermarking Scheme for Copyright Protection and Content Authentication of Digital Audio

This paper proposes a novel multi-watermarking scheme which embeds three watermarks with different purposes into the same digital audio file. To be specific, the robust watermark is resistant against various signal attacks, thus realizes the function of copyright protection. The semi-fragile watermark is robust against common signal operations but sensitive to malicious tampering and can locate the tampered area, which is used to authenticate the content of digital audio. The fragile watermark is sensitive to any small changes of the audio signal thus can verify its integrity. Experimental results show good transparency of the proposed scheme and the three different watermarks do not interfere with each other. In addition, all the three watermarks are blind-extracted, which is useful in practical applications.