Information Hiding in Speech Signals for Secure Communication

Chapter 4

The G.721-Based Speech Information Hiding Approach

Abstract

G.721 is an ITU Telecommunications Standardization Sector standard codec that uses adaptive differential pulse code modulation (ADPCM) to compress data. This chapter focuses on speech information hiding based on the G.721 scheme and proposes a novel approach for embedding 2.4 kbps MELP-coded secret speech information into 32 kbps G.721 for realizing G.721-based real-time secure communication. This approach adopts the LPC-IH-FS and BD-IE-MES algorithms to complete the operations of embedding secret speech information into, and extracting that information from, the G.721 scheme. Experimental results show that this approach meets the requirements of information hiding, satisfies ...