Research on covert communication channel based on modulation of common compressed speech codec

Area of Science:

• Computer Science
• Information Security
• Signal Processing

Background:

• Multimedia applications like Voice over Internet Protocol (VoIP) and mobile communications are widespread.
• Establishing covert communication channels within these popular platforms is an active research area.

Purpose of the Study:

• To present a novel and effective method for constructing a covert communication channel over compressed speech streams.
• To embed secret information within common compressed speech data without compromising audio quality.

Main Methods:

• Analysis of excitation pulse position characteristics in ITU-T G.723.1 and G.729A speech codecs.
• Development of a covert channel by finely modulating the codes of excitation pulse positions based on secret information.
• Utilization of odd/even characteristics of pulse code positions to increase embedding capacity.

Main Results:

• Experimental validation across various scenarios demonstrates the effectiveness of the proposed method.
• The approach achieves a high degree of secrecy for hidden information.
• The method exhibits superior information embedding efficacy compared to existing techniques.

Conclusions:

• The proposed method offers a secure and efficient way to establish covert communication channels within compressed speech.
• Modulating speech codec pulse positions presents a viable strategy for steganography in multimedia communications.
• Further research can explore broader applications and optimizations for this covert channel technique.