Frequency or time domain speech scrambling technique and system which does not require any frame synchronization

摘要

The present invention relates to speech scrambling techniques and systems and in particular to a frequency or time domain speech scrambling technique and system which does not require any frame synchronization. This invention is technique and system for scrambling speech signal in frequency or time domain by means of speech analysis- synthesis techniques. The system described above is very attractive because it has avoided the frame synchronization problem. The existing analog telephone channel can be utilized directly for transmission because bandwidth expansion is completely controllable. In addition, the "key space" is very large and a high degree of security can be achieved.