Design of a discrete cosine transform based speech scrambler
Ed Dawson · Electronics Letters · 1991
A discrete cosine transform based speech-encryption system, suitable for communication over band-limited telephone channels, is described. An energy modification technique is presented which dramatically reduces the residual intelligibiltiy of the scrambled speech. In addition, a method used to reduce the undesirable effects of band limitation is described. Simulation results are included which demonstrate the improved performance of the scheme.