Information Hiding in Real-Time VoIP Streams

The real-time speech hiding is to hide the secret speech into a cover speech in real-time communication systems. By hiding one secret speech into the cover speech, we can get a stego speech, which sounds meaningful and indistinguishable from the original cover speech. Therefore, even if the attackers catch the audio packets on Internet, they would not notice that there is another speech hidden inside it. In this paper, we propose a scheme for speech hiding in a real-time communication system such as voice over Internet Protocol (VoIP). We propose a novel design of real-time speech hiding for G.711 codec, which is widely supported by almost every VoIP device. Experimental results show that the processing time for the proposed algorithm takes only 0.257 ms, which is suitable for real-time VoIP applications.