Speech watermarking in wireless sensor network using wavelet transform

In this paper, for secure transmission of speech signal in wireless sensor, a new method based on wavelet transform has been proposed. In this methodology, speech signal is compressed and encrypted simultaneously using characteristics of wavelet transform. The output speech which is in form of an obscure bit stream is required to be inserted in carrier signal. For insertion, fivestage wavelet transform is applied on speech signal and the optimum sub-bands are selected. The simulation results show that the proposed method provides higher security, lower complexity and lower consuming energy in comparison with popular methods in wireless sensor networks.