Detection of Tampering in Speech Signals with Inaudible Watermarking Technique

There have recently been serious social issues involved in multimedia signal processing such as malicious attacks and tampering with digital audio/speech signals. Fragile speech watermarking is a technique that enables the detection of tampering with the original signals. We previously proposed an inaudible digital-audio watermarking approach based on cochlear delay. We investigated how the proposed approach could be developed as fragile watermarking by considering its robustness against meaningful processing and fragility against malicious modifications. We evaluated the proposed method of detecting tampering with speech by carrying out three objective tests (PESQ, LSD, and bit-detection), robustness tests on speech coding, and a fragility test on malicious modifications. The results revealed that the proposed approach could detect the positions of tampering as well as the forms it took.