A new perfect analog encryption method which does not expand bandwidth
Zhang Hailin Wang Yumin
This paper deals with the problems associated with scrambling speecn signals, and presents a new perfect analog encryption method, temporarily called Modele-basis-educated. Transform sample Pseudo-randomly Masking technique (MTPM), which can be used in the generalized orthogonal-transform-domain-sample-scrambling schemes such as KLT, DCT, WHT, PST, DFT, etc. It is shown in the paper that this method can not only provide a perfect secrecy of speech in theory, but also keep the bandwidth of scrambled signal from expanding, with a very small mean square error.