SPEECH SIGNAL ENCRYPTION USING WAVELET BASED ECHO HIDING ENCODER- DECODER PAIR ARCHITECTURE

摘要

Signal Encryption is a significant approach in hiding covert signals in a network. Steganography provides an apt methodology for hiding sensitive information in multimedia, with enhanced security and reduced possibility of unauthorized decoding. The need for increased signal encryption efficiency and hiding capacity, lays the foundation for the invention stated below. Here in, speech signals have been encrypted with secret message information to be transmitted over a network. The encryption has been done using the concepts of Audio Steganography. The block level architecture of the encoder-decoder pair has been disclosed. The information bit is pseudo-randomly hidden inside the speech carrier signal with highest efficiency while preserving data security. The message has been introduced in the form of echo signals introduced to a wavelet decomposed speech signal. The displaced echo signal added to the main wavelet decomposed speech encodes the message bit in the audio signal with zero loss of data and enhanced noise immunity. The major application of this technology is found in information hiding and security in communication networks especially in defence related areas. Defence communications require enhanced security in data encryption and the invention stated here in, tries to achieve that without compromising the transmission ability. The applicability of the design for real time signal encryption provides further research scope for the invention.