Dual Quantum Audio Watermarking Schemes Based on Quantum Discrete Cosine Transform

The study explores the implementation of watermarking schemes for quantum audio signals based on quantum Discrete Cosine Transform (qDCT). Dual Quantum Audio Watermarking (QAW) schemes, i.e. QAW-I and QAW-II, are proposed by utilizing the property of strong energy compaction of the qDCT. The qDCT transforms the host quantum audio signal which is encoded as an FRQA (Flexible Representation for Quantum Audio) content from time to frequency domain. To retain the high imperceptibility of the dual QAW schemes, the quantum watermark is embedded into the high-frequency portions of host quantum audio signal after the qDCT operation. The circuit networks to execute the embedding and extraction procedures of QAW-I and QAW-II schemes are designed. In addition, simulation-based experiments are conducted to demonstrate their implementation and conclude their advantages in terms of imperceptibility and robustness.