Multicast Covert Communication Based on Multivariate Sequence Mapping Spread Spectrum Orthogonal Modulation

Astract-With the increasing demand for information security, multicast communication, as an important means of transmitting information from a single source to multiple receivers, is becoming more widely used. However, existing multicast steganography methods have limitations in terms of embedding capacity, especially in multi-user communication scenarios, lacking dynamic adaptability and flexibility to meet the needs of covert communication in complex situations. Therefore, this paper proposes a multi-sequence mapping steganography method based on dynamically generated spread-spectrum orthogonal codes using shared keys. This method dynamically generates Walsh codes through shared keys to ensure consistency between the communication parties. Subsequently, the secret information is mapped into multi-sequence and embedded into the small value region of the Quantized Modified Discrete Cosine Transform (QMDCT) coefficients of Advanced Audio Coding (AAC) audio using spread-spectrum orthogonal techniques. This method effectively reduces signal distortion and enhances the secrecy of the embedded information. Experimental results show that this method exhibits excellent performance in terms of embedding capacity and confidentiality, better meeting the needs of multicast covert communication.