Time-spread echo method for digital audio watermarking with random interval

Conventional echo hiding methods have simple encoding and decoding process, Robustness to MP3 compression, but the correct rate of extracted information need be improved. To copy with this problem, we propose a time-spread echo with random intervals. The encoding process generates an interval sequence to dominate the intervals of echoes. The echo is added into the audio according to the interval sequence, and the values of the gain of two adjacent echoes are opposite. The difference between embedding ‘0’ and ‘1’ is that the gain of the corresponding echo is opposite. The decoding process using the dispreading sequence generated by the key spread the cepstrum of the cover audio. Experiment results show our algorithm can effectively improve correct rate of extracted information.