An information-hiding model for secure communication

This paper presents an speech information hiding model for transmitting secret speech through subliminal channel covertly for secure communication over PSTN (Public Switched Telephone Network) or VoIP (Voice over Internet Protocol). This model's main statement is that the embedding operation of a secure communication system should work indeterminate from the attacker's point of view. This model for secure communication based on the technique of information hiding has more severe requirements on the performances of data embedding than watermarking and fingerprinting in the aspects of real time, hiding capacity, and speech quality. Experiments show that this model meets the requirement of secure communication and suits for practical application of covert communication. The security analysis of this model by means of information theory and actual test proved that it is theoretically and practically secure. This information theory based model can be commonly used to help design a system of speech secure communication with different coding schemes.