Concealing The Secret Messages In Inactive Frames Using Source Codec

Abstract: The paper makes use of high capacity steganography algorithm for producing high data embedding capacity. This is achieved by embedding data in low bit rate audio stream. The term “VoIP” describes the digitalization, compression and transmission of analog audio signals (in majority of speech signals) from a sender to a receiver using IP packets. Any system can be as client and any system made as server. When the client speaks the audio stream will be in the form of Analog signal. By using improved Voice Activity Detection (VAD) algorithm the analog signal is separated into active frame and inactive based on the value of energy and threshold. Active frames are of high bit rate and Inactive frames are of low bit rate. When the value of the energy is less than that of threshold then the signal is non-speech signal ,i.e. the signal is inactive then it comes under Inactive frame. Voice data will be embedded in active frame and text data will be embedded in inactive frame. High capacity steganography algorithm is used to embedded the data in inactive frame. G.723.1 codec is used to compress the audio stream. Then the voice data and text data is received at the receiver end in the form of analog signal. The communication in live so that it ensures security. Therefore this paper meets the requirements of information concealing, and satisfies the secure communication speech .

Keywords: Steganography, Inactive frames, Concealing, VoIP,Speech codec