An echo-hiding watermarking technique based on bilateral symmetric time spread kernel

Echo hiding is an audio watermarking method where information is embedded in the echo delay. A bilateral time spread echo kernel is proposed to improve robustness against malicious attacks as well as enhance the detection performance by increasing the peak value of the kernel cepstrum at the echo delay time. Based on the spreading property of PN sequences and expansions of logarithm and binomial, a closed-form detection gain formula is derived analytically. Computer simulation confirms the proposed method is effective and outperforms the previous unilateral method.