Date Added: Apr 2011
An effective covert communication system can be achieved based on steganography in stream media such as VoIP (Voice over IP), and the LSB-based (Least-Significant-Bit) methods are the most popular strategies. However, LSB embedding in the flat regions of the speech could inevitably bring about the perceptible distortion leading to the degradation of speech quality. Besides, LSB methods are vulnerable for diverse corresponding steganalysis like RS detection. This paper presents an adaptive steganography scheme that selects lower embedding bit rate in the flat blocks, while chooses higher embedding bit rate in the sharp blocks.