Steganography in Inactive Frames of VoIP Streams Encoded by Source Codec

作者：Huang Yong Feng^*; Tang Shanyu; Yuan Jian

来源：IEEE Transactions on Information Forensics and Security, 2011, 6(2): 296-306.

DOI：10.1109/TIFS.2011.2108649

• Audio streams
• inactive frames
• steganography
• Voice over Internet Protocol (VoIP)

This paper describes a novel high-capacity steganography algorithm for embedding data in the inactive frames of low bit rate audio streams encoded by G.723.1 source codec, which is used extensively in Voice over Internet Protocol (VoIP). This study reveals that, contrary to existing thought, the inactive frames of VoIP streams are more suitable for data embedding than the active frames of the streams; that is, steganography in the inactive audio frames attains a larger data embedding capacity than that in the active audio frames under the same imperceptibility. By analyzing the concealment of steganography in the inactive frames of low bit rate audio streams encoded by G. 723.1 codec with 6.3 kb/s, the authors propose a new algorithm for steganography in different speech parameters of the inactive frames. Performance evaluation shows embedding data in various speech parameters led to different levels of concealment. An improved voice activity detection algorithm is suggested for detecting inactive audio frames taking into packet loss account. Experimental results show our proposed steganography algorithm not only achieved perfect imperceptibility but also gained a high data embedding rate up to 101 bits/frame, indicating that the data embedding capacity of the proposed algorithm is very much larger than those of previously suggested algorithms.

• 出版日期2011-6
• 单位清华大学